@article{doi101130001676061960711137mcasmf20co2, author = "Moberly, Ralph", title = "MORRISON, CLOVERLY, AND SYKES MOUNTAIN FORMATIONS, NORTHERN BIGHORN BASIN, WYOMING AND MONTANA", year = "1960", journal = "Geological Society of America Bulletin", url = "https://doi.org/10.1130/0016-7606(1960)71[1137:mcasmf]2.0.co;2", doi = "10.1130/0016-7606(1960)71[1137:mcasmf]2.0.co;2", openalex = "W1978542375" } @techreport{ostrom1969osteology1, author = "Ostrom, J. H", title = "Osteology of Deinonychus antirrhopus, an unusual theropod dinosaur from the Lower Cretaceous of Montana", year = "1969", howpublished = "Bulletin of the Peabody Museum of Natural History, v. 30, p. 1-165", note = "talkorigins\_source = {true}; raw\_reference = {Ostrom, J. H., 1969, Osteology of Deinonychus antirrhopus, an unusual theropod dinosaur from the Lower Cretaceous of Montana: Bulletin of the Peabody Museum of Natural History, v. 30, p. 1-165.}" } @techreport{ostrom1970stratigraphy2, author = "Ostrom, J. H", title = "Stratigraphy and paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin area", year = "1970", howpublished = "Bulletin of the Peabody Museum of Natural History, v. 35, p. 1-234", note = "talkorigins\_source = {true}; raw\_reference = {Ostrom, J. H., 1970, Stratigraphy and paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin area: Bulletin of the Peabody Museum of Natural History, v. 35, p. 1-234.}" } @article{olson1972stratigraphy, author = "Olson, Everett C.", title = "Stratigraphy and Paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin Area, Wyoming and Montana. John H. Ostrom", year = "1972", journal = "The Quarterly Review of Biology", url = "https://doi.org/10.1086/407120", doi = "10.1086/407120", number = "1", openalex = "W2091904599", pages = "78-78", volume = "47" } @article{doi10130603b599f416d111d78645000102c1865d, author = "Jordan, Teresa E.", title = "Thrust Loads and Foreland Basin Evolution, Cretaceous, Western United States", year = "1981", journal = "AAPG Bulletin", abstract = "ABSTRACT Two-dimensional modeling of loading during the formation of the Idaho-Wyoming thrust belt shows that regional isostatic compensation by flexure of an elastic lithosphere is sufficient to control the formation of a foreland basin. The flexural rigidity of the lithosphere is inferred to have been approximately 1023 Nm (1030 dyne cm), on the basis of palinspastic comparison of predicted downwarping, due to the thrust plate loads, to the shape of the sedimentary wedge on the west side of the Cretaceous Western Interior seaway. Erosion of part of the uplifted thrust plates redistributed the load, depositing it farther to the east, thereby causing subsidence over a much wider area than could have been accomplished only by the loading by thrust plates. Paleotopography after major Cretaceous thrust events was calculated. The resulting mountainous terrain, gentle alluvial plain, and flat sea floor correspond well with the topography of the modern foreland thrust belt and basin system in the Andes of South America and to paleogeographic reconstructions in the western United States thrust belt. Topography is controlled by the subsurface geometry of the thrust faults, particularly the positions of ramp zones, and by isostatic subsidence.", url = "https://doi.org/10.1306/03b599f4-16d1-11d7-8645000102c1865d", doi = "10.1306/03b599f4-16d1-11d7-8645000102c1865d", openalex = "W2083997111", references = "doi1010160012821x78900365, doi1010160040195176900044, doi101029jb075i020p03941, doi101029jb083ib12p05989, doi101111j1365246x1981tb02715x, doi101130001676061978891389rbeass20co2, doi1013065d25cbb316c111d78645000102c1865d, doi101306a663386e16c011d78645000102c1865d, doi101306st6398c16, doi102110pec74220001, openalexw2474977981, openalexw586757543" } @article{doi10108002724634198210011915, author = "Estes, Richard and Sanchíz, Borja", title = "Early Cretaceous Lower Vertebrates from Galve (Teruel), Spain", year = "1982", journal = "Journal of Vertebrate Paleontology", abstract = "ABSTRACT The Early Cretaceous (Barremian–Aptian) lower vertebrate fauna from Galve, Spain, includes two hybodontid sharks, Hybodus parvidens and Lonchidion microselachos n. sp., as well as fragmentary remains of characteristic Mesozoic bony fishes. The salamander AIbanerpeton cf. megacephalus (Prosirenidae) is most similar to Jurassic Portuguese specimens of this species. Galverpeton ibericum n. gen. et sp. (family incertae sedis) was probably a slim-bodied animal; it resembles the ambystomatoid–plethodontoid salamanders and is the earliest record of the more derived salamander groups. The first disarticulated specimens of the Upper Jurassic or Lower Cretaceous discoglossid frog Eodiscoglossus santonjae permit refinement of the diagnosis of this primitive frog. A variety of small reptiles is also present, including lizards, crocodilians and dinosaurs; the latter are notable in being represented by teeth of very small (young?) animals. The Galve assemblage includes primarily freshwater forms, and, based on a limited sample, shows broad similarities to other Early Cretaceous faunas in England and (to a slightly lesser degree) North America. It also seems to indicate the beginnings of endemism in the Iberian Peninsula and related areas at the beginning of the Cretaceous, a time when Laurasia was still a single unit.", url = "https://doi.org/10.1080/02724634.1982.10011915", doi = "10.1080/02724634.1982.10011915", openalex = "W2015681697", references = "doi105962p150189, openalexw2246336267" } @article{doi10108002724634198810011681, author = "Jenkins, Farish A. and Schaff, Charles R.", title = "The Early Cretaceous mammal Gobiconodon (Mammalia, Triconodonta) from the Cloverly Formation in Montana", year = "1988", journal = "Journal of Vertebrate Paleontology", abstract = "ABSTRACT Gobiconodon ostromi, sp. nov., described from two partial skeletons collected from the Cloverly Formation in southcentral Montana, is closely related to Gobiconodon borissiaki Trofimov (1978) from the Early Cretaceous of Mongolia. The unusual dental characters of this new form are enlarged caniniform incisors, reduced canines, and replacement of the molariform teeth that lie distal to the presumptive premolars. Despite the fact that the molariform occlusal pattern is the same as in Amphilestes of the Middle Jurassic and the overall structure of the molariform teeth is comparable to that in amphilestid triconodonts, the dentition is otherwise so anomalous that Gobiconodon is assigned to a new family. The scapula possesses a supraspinous fossa and an apparently large coracoid. The humerus exhibits large deltopectoral and medial crests, and protuberant epicondyles; the planes of the proximal and distal halves of this bone are substantially offset. The pelvis conforms to a generalized mammalian pattern. A deep fossa of unknown function occurs on the dorsal surface of the lesser trochanter; the greater trochanter extends distally well down onto the shaft. A spur-like bone appears to represent an extratarsal element. In overall body size, Gobiconodon ostromi, sp. nov., is comparable to Didelphis virginiana but in its limb and vertebral proportions is more robust.", url = "https://doi.org/10.1080/02724634.1988.10011681", doi = "10.1080/02724634.1988.10011681", openalex = "W2041142773", references = "doi101002aja1001370304, doi101002jmor1051670308, doi101002jmor1051850203, doi101098rstb19760022, doi101111j109636421981tb01127x, doi101111j109636421985tb01500x, doi101111j1469185x1968tb00966x, doi105281zenodo16386718, doi105962bhltitle3460, openalexw1539913220" } @misc{paul1988the3, author = "Paul, G. S", title = "THe horned theropods of the Morrison and Great Oolite, and the sickle-claw theropods of the Cloverly, Djadokhta and Judith River", year = "1988", howpublished = "Hunteria, v. 2, p. 1-9", note = "talkorigins\_source = {true}; raw\_reference = {Paul, G. S., 1988, THe horned theropods of the Morrison and Great Oolite, and the sickle-claw theropods of the Cloverly, Djadokhta and Judith River: Hunteria, v. 2, p. 1-9.}" } @article{doi101016019566719190005w, author = "Allen, P. and Wimbledon, William A.P.", title = "Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas", year = "1991", journal = "Cretaceous Research", url = "https://doi.org/10.1016/0195-6671(91)90005-w", doi = "10.1016/0195-6671(91)90005-w", openalex = "W2048119552", references = "doi101111j136530911988tb00992x" } @article{doi101111j136521171992tb00050x, author = "DeCelles, Peter G. and Burden, Elliott T.", title = "Non‐marine sedimentation in the overfilled part of the Jurassic‐Cretaceous Cordilleran foreland basin: Morrison and Cloverly Formations, central Wyoming, USA", year = "1992", journal = "Basin Research", abstract = "Abstract Lithostratigraphic, chronostratigraphic, sedimentological and penological data from the Upper Jurassic‐Lower Cretaceous Morrison and Cloverly Formations in central Wyoming allow detailed characterization of the early history of the central part of the Cordilleran foreland basin. The Morrison is divisible into three informal members: (1) a lower sandstone, deposited by a complex coastal dune‐foreshore–fluvial system during retreat of the Sundance sea; (2) a middle mudstone, deposited by muddy fluvial and ephemeral lacustrine systems during a period of regional, seasonal aridity; and (3) an upper sandstone, deposited by a sandy fluvial system of variable sinuosity. The overlying Cloverly Formation is divisible into two informal members: (1) a lower mudstone (previously considered as part of the Morrison Formation), deposited by muddy fluvial and lacustrine systems; and (2) an upper chert‐pebble conglomerate and sandstone, deposited primarily by gravel‐dominant braided rivers. Palynological data and a single fission‐track date indicate that the lower part of the middle Morrison mudstone is early to middle Oxfordian and the upper part of the lower Cloverly mudstone is Valanginian. Morrison sandstones are subarkosic, with average \%QFL = 91,6, 3 and \%QmFLt = 83, 6, 11. Cloverly sandstones are cherty litharenites and sublitharenites, with average \%QFL = 99.6, 0,0.4 and \%QmFLt = 82,0,18 (Gazzi‐Dickinson point‐counting method). Palaeocurrent data and sandstone compositions indicate a complex provenance including exirrabasinal sources in lower Mesozoic and upper Palaeozoic sedimentary and volcanic rocks of the Cordillera and intrabasinal sources of Proterozoic clasts in south‐central Wyoming. Cloverly sandstone compositions in the eastern part of the study area were influenced by short‐term fluvial reworking within the basin. The thickness of the composite Morrison‐Cloverly succession is practically constant over a distance of several hundred km east of the Idaho‐Wyoming thrust belt, and its internal chronostratigraphic zones are subparallel. On the other hand, equivalent strata in the Gannett Group of the thrust belt are at least three times thicker. This indicates that the Morrison and Cloverly in central Wyoming were deposited within the overfilled part of the foreland basin. Preliminary regional correlation indicates that coarse‐grained lithofacies in these rocks are significantly time‐transgressive, generally becoming younger toward the E and NE. Overfilling of the early Cordilleran foreland basin in central Wyoming was accomplished by progradation from the W and S. In spite of their three‐dimensional (3D) complexity, the Morrison and Cloverly Formations generally confirm theoretical model predictions for overfilled foreland basins.", url = "https://doi.org/10.1111/j.1365-2117.1992.tb00050.x", doi = "10.1111/j.1365-2117.1992.tb00050.x", openalex = "W1994783903", references = "doi1010160012825277900551, doi101111j1365246x1981tb02715x, doi10113000167606198394222ponaps20co2, doi101130mem151p355, doi10130603b599f416d111d78645000102c1865d, doi101306212f83b92b2411d78648000102c1865d, doi1013062f9188fb16ce11d78645000102c1865d, doi102110pec88010071, doi102136sssaj196503615995002900020004x, openalexw1912927042" } @article{doi101111j136521171992tb00051x, author = "Meyers, James and Suttner, Lee J. and Furer, L.C. and May, Michael T. and Soreghan, Michael J.", title = "Intrabasinal tectonic control on fluvial sandstone bodies in the Cloverly Formation (Early Cretaceous), west‐central Wyoming, USA", year = "1992", journal = "Basin Research", abstract = "Abstract Temporal and spatial changes in alluvial sand‐body geometry and palaeodispersal patterns of the lower part of the Cloverly Formation (Early Cretaceous) in west‐central Wyoming suggest differential uplift within the developing medial to distal foreland basin and existence of subtle structurally controlled topography nearly 60 Myr before classic Laramide uplift in the Wyoming foreland province. This intraforeland structural topography exerted a significant control on dispersal and deposition of widespread gravels of Neocomian‐Aptian age. Surface studies have established the presence of two conglomeratic sandstones in the Cloverly Formation in the western Wind River Basin. Both conglomeratic sandstones are chert arenites, but the lower conglomeratic sandstone is characterized by dark chert pebbles derived from western and southwestern extrabasinal sources and was deposited by braided rivers, whereas the upper conglomeratic sandstone is characterized by intraformational clasts derived locally from adjacent floodplains and deposited by NE‐flowing rivers of moderate sinuosity which carried a higher proportion of suspended load in stable bank‐confined channels. Surface and subsurface mapping of sandstone‐body geometry in the lower dark chert‐pebble conglomeratic sandstone, together with palaeocurrent analysis of trough cross‐bedding, reveal a major NE‐flowing trunk river system in the area. Lithological correlation of surface sections to adjacent well logs, together with regional format correlation of fine‐grained intervals in well logs up to 120 km E of the outcrop belt, enable detailed mapping of the trunk system. The trunk system was approximately 5–10 km wide, and may have been confined by subtle structural topography developed by recurrent differential uplift along NE‐trending fractures in Archaean basement rocks. The fractures are along strike with diabase dike swarms and faults mapped in Archaean basement rocks of the Laramide Wind River uplift. The lower chert‐pebble sandstone is absent for a lateral distance of at least 30 km between these lineaments, including an area of at least 1000 km 2, indicating the existence of a low NE‐SW‐trending interfluve perpendicular to the axis of the modern Wind River Range. Early Cretaceous development of structural topography and partitioning of the medial to distal foreland basin of west‐central Wyoming were most likely controlled by tectonic reactivation and differential uplift along fractures in Archaean basement rocks in response to early thrust loading and intraplate stresses during initial subsidence of the foreland basin.", url = "https://doi.org/10.1111/j.1365-2117.1992.tb00051.x", doi = "10.1111/j.1365-2117.1992.tb00051.x", openalex = "W2172067183" } @article{openalexw1533729705, author = "Peterson, Fred", title = "Sand Dunes, Sabkhas, Streams, and Shallow Seas: Jurassic Paleogeography in the Southern Part of the Western Interior Basin", year = "1994", abstract = "Abstract Jurassic rocks in the southern part of the Jurassic Western Interior basin consist largely of clastic materials, with considerably smaller quantities of carbonates and evaporites. The rocks were deposited in nonmarine environments and in marine waters that, at times, had moderately to highly elevated salinities and tended to be inimical to life. A magmatic arc bordered the southwest side of the continent and influenced sedimentation in the Western Interior by episodically providing voluminous quantities of volcanic ash to the region. The arc also produced elevated terrain and a rain shadow that at least partly determined the climate in the Western Interior. The climate was warm and dry and played an important role in sedimentation by fostering precipitation of evaporites, formation of extensive eolian dune fields, and development of a large saline-alkaline lake at the end of the period. The lithologic succession includes at least 8 local or region-wide unconformities, and the system is separated from both the Triassic and Cretaceous Systems by additional region-wide unconformities. All except one of these surfaces record the effects of tectonic adjustments in the region that probably occurred continuously but were made more noticeable by the slight but perceptible structural discordances at the unconformities. Some of the unconformities can be related to global sea-level fluctuations that have been proposed in the literature, but the known structural activity in the region, the poor age calibration of the beds, and questions concerning the validity and documentation of proposed global sea-level curves make it difficult to confidently relate most of the rock sequences to global eustasy. Lower Jurassic rocks, not present east of the Colorado Plateau, were deposited in large ergs represented by the Wingate Sandstone and the younger Navajo Sandstone and their correlative beds. Eolian sedimentation was continuous in the northern part of the region, but farther south in the central part of the Colorado Plateau, it was disrupted after deposition of the Wingate by a flood of fluvial sand (Kayenta Formation and correlative beds) that was shed westward off the ancestral Rocky Mountains in about the middle of the epoch. The Mogollon slope on the northeast side of the magmatic arc in southern Arizona, also was a source of fluvial clastic debris shed onto the southwestern part of the Colorado Plateau. Middle Jurassic rocks were deposited during five marine transgressive-regressive cycles in which an interior seaway that was mostly in Idaho and Wyoming expanded and contracted, there by moving the strandline back and forth across the northern and northwestern parts of the region. Eolian sands, evaporites consisting of gypsum or anhydrite and rare halite, and marine limestones form distinctive deposits of the epoch. Rapid subsidence in the Utah-Idaho trough along the west side of the region probably was caused by thrust loading farther west in the western Elko highlands during the early phase of the Elko orogeny. The principal source area for fluvial clastics transported into the southern part of the region during most of this time was the Mogollon slope farther south. In contrast, the principal source area for eolian clastics was to the north in shoreface sands along the southern shoreline of the Sundance seaway. Most of the clastic material in the Utah-Idaho trough probably was derived from the western Elko highlands. During the latest Middle Jurassic (late Callovian), thrust faulting ceased in the Elko orogenic belt and the Utah-Idaho trough or foredeep was inverted to a highland area called the eastern Elko highlands. This area then became an important source of sediment for the region farther east. Deposition of Upper Jurassic strata began with two additional marine transgressions during Oxfordian and possibly earliest Kimmeridgian time. These were succeeded by continental sedimentation of the Morrison and related formations throughout the entire Western Interior basin. The Mogollon slope as well as the western and eastern Elko high lands were the principal source areas for clastic sediment. Uplift continued in the eastern Elko highlands as a continuation of the later or crustal rebound phase of the Elko orogeny, and thrust faulting, this time in the eastern Elko highlands, evidently did not begin until the Sevier orogeny in late Early Cretaceous time.", openalex = "W1533729705" } @article{doi101306d426822a2b2611d78648000102c1865d, author = "Olsén, Thomas and Steel, R. J. and Hogseth, K. and Skar, T. and Røe, Signe‐Line", title = "Sequential architecture in a fluvial succession; sequence stratigraphy in the Upper Cretaceous Mesaverde Group, Prince Canyon, Utah", year = "1995", journal = "Journal of Sedimentary Research", abstract = "ABSTRACT Five unconformity-bounded sequences have been documented within a 1300 m thick succession of predominantly fluvial Upper Cretaceous and Lower Tertiary deposits in the Price Canyon area of the westernmost part of the Book Cliffs, east-central Utah, U.S.A. This area experienced major tectonically induced changes in the paleogeography during deposition. The earliest fluvial deposits in the study area were formed in a relatively simple foreland basin setting in front of the Sevier Orogenic Belt, and contain more marine influence than previously recorded. Following a gradual termination of thrusting, sedimentation became increasingly controlled by uplift of the San Rafael Swell to the southeast. Our studies suggest that the fluvial systems in the upper part of the succession alternated bet een being confined within a valley open towards the north and being more directly eastward flowing. On the basis of the observed sequences, an idealized model of alluvial sequences, whose internal architecture can be related to a fall-rise-fall cycle of the stratigraphic base level, has been established. Upward or downward changes in the position of this base level dictate the creation and destruction of accommodation on the alluvial plain and therefore exert a direct control on the sequential architecture and sandstone body geometry of fluvial successions. In our model, the basal sequence boundary is overlain by an amalgamated fluvial sandstone sheet. The sheet is succeeded by a fining-upward, more mudstone-rich level with more isolated sandstone bodies, and this level may culminate in a marine or lacustrine transgression. The upper part of the sequence may show a coarsening-upward trend heralding the next phase of base-level fall and sequence-boundary generation. Use of the suggested model has the potential to refine existing lithostratigraphic schemes and, given the higher resolution and more detailed correlation, may significantly improve paleogeographic reconstructions and aid in prediction of potentially hydrocarbon-bearing reservoirs. A revised and refined lithostratigraphy has been established on the basis of alluvial sequence analysis. The lower half of the succession forms the youngest part of a major eastward-prograding clastic tongue, the Mesaverde Group, and is Campanian. We divide this part into the Blackhawk, Castlegate, and Price River Formations. The rest of the succession is Maastrichtian to Paleocene and is referred to the North Horn Formation. This formation was deposited in an intermontane setting.", url = "https://doi.org/10.1306/d426822a-2b26-11d7-8648000102c1865d", doi = "10.1306/d426822a-2b26-11d7-8648000102c1865d", openalex = "W2110366794", references = "doi101111j136521171992tb00050x, doi101306m41456c20" } @incollection{doi102110pec95520097, author = "May, Michael T. and Furer, L.C. and Kvale, Erik P. and Suttner, Lee J. and Johnson, Gary D. and Meyers, James", title = "CHRONOSTRATIGRAPHY AND TECTONIC SIGNIFICANCE OF LOWER CRETACEOUS CONGLOMERATES IN THE FORELAND OF CENTRAL WYOMING", year = "1995", booktitle = "SEPM (Society for Sedimentary Geology) eBooks", abstract = "Intra and inter basinal correlations between outcrop and subsurface over most of northern and central Wyoming indicate that chert bearing conglomerates in the lower Cretaceous Cloverly Formation in the foreland of central Wyoming occupy three distinct stratigraphic levels The two older conglomerates are in the lower Cloverly Formation in the western Wind River Basin and reflect northerly to northeasterly dispersal The youngest conglomerate is in the upper Cloverly Formation in the eastern portion of the basin gravels in this interval also were transported to the north and northeast The two older conglomerates are separated from the youngest conglomerate by up to 35 m of purple to gray smectite rich mudstones that contain distinctive 10 to 90 em thick layers of white to dark green devitrified tuff as well as silica and carbonate nodular beds Fission track ages of 125 128 Ma have been obtained from three samples of tuff in the Wind River Basin These tuffs can be correlated to prominent tuffs further north in the Bighorn Basin where a paleomagnetic stratigraphy has been established Fission track ages of zircons from devitrified tuff layers and magnetostratigraphy of mudstones suggest that the older two conglomerates in the Wind River Basin were deposited between 133 and 128 Ma and the youngest conglomerate at about 118 to 115 Ma Three dimensional spatially controlled and temporally constrained reconstructions of paleodrainage systems for Cloverly conglom erates illustrate the complexity of fluvial drainage networks within the evolving Early Cretaceous foreland basin Sand body geometry and dispersal patterns within these fluvial networks were partially controlled by tectonic activity which created a series of northeast oriented horsts and grabens in the Wind River Basin Location of trunk rivers was controlled by the positions of grabens within the basin", url = "https://doi.org/10.2110/pec.95.52.0097", doi = "10.2110/pec.95.52.0097", openalex = "W2254411674", references = "doi101016b9780080122779500159, doi101111j136521171992tb00051x, doi101130001676061985961419acajg20co2, doi1011300016760619891010864tpolcg23co2, doi10113000917613198614388toitit20co2, doi1011300091761319880160501tpsmof23co2, doi101130gsab55951, doi101130mem171, doi10130603b5b74016d111d78645000102c1865d, doi101306a663386e16c011d78645000102c1865d, kvaleNonepaleoenvironments" } @article{doi101111j136530911997tb01531x, author = "Kilibarda, Zoran and Loope, David B.", title = "Jurassic aeolian oolite on a palaeohigh in the Sundance Sea, Bighorn Basin, Wyoming", year = "1997", journal = "Sedimentology", abstract = "ABSTRACT Aeolian limestones are widespread in the Quaternary record and have been identified in outcrops and cores of late Palaeozoic strata. These rocks have been interpreted as a low latitude signal of glacio‐eustatic sea level fluctuations and have not been previously reported from the Mesozoic or from other episodes of earth history generally believed to have been non‐glacial. Numerous lenticular bodies of cross‐stratified oolite lie near the contact between the lower and upper members of the mudstone‐dominated lower Sundance Formation (Middle and Upper Jurassic) in the Bighorn Basin of north‐central Wyoming, USA. The lenses, up to 12 m thick, contain sedimentary structures diagnostic of aeolian deposition. Inversely graded laminae within thick sets of cross‐strata were deposited by climbing wind ripples. Adhesion structures and evenly dispersed lag granules are present in flat‐bedded strata at the bases of several of the oolite bodies. Thin sections reveal abundant intergranular micrite of vadose origin. The lenses appear to represent virtually intact, isolated aeolian bedforms that migrated across a nearly sand‐free deflation surface. When the Sundance Sea transgressed the dunes, a thin (<1 m thick), wave‐rippled, oolite veneer formed on the upper surface of the aeolianite. Previous workers, primarily on the basis of sedimentary structures in the veneer, interpreted the oolite lenses as tidal sand bodies. The dunes provide clear evidence of widespread subaerial exposure on the crest and north flank of the Sheridan Arch. This structural high was delineated by previous workers who demonstrated thinning of pre‐upper‐Sundance Formation strata and localized development of ooid shoals. Ooids that formed in shoals on the windward (southern) side of the palaeohigh were exposed and deflated during lowstand. Thin, scour‐filling ooid grainstone lenses that crop out in the southern part of the study area represent remnants of the marine beds that sourced the aeolianites. Farther north (down‐wind), oolitic dunes prograded over thinly laminated lagoonal silts. When relative sea level began to rise, the uncemented dunes were buried under fine‐grained marine sediment as the lee side of a low‐relief island was inundated.", url = "https://doi.org/10.1111/j.1365-3091.1997.tb01531.x", doi = "10.1111/j.1365-3091.1997.tb01531.x", openalex = "W2089471903" } @article{cifelli1998triconodont, author = "Cifelli, Richard L. and Wible, John R. and Jenkins, Farish A.", title = "Triconodont mammals from the Cloverly Formation (Lower Cretaceous), Montana and Wyoming", year = "1998", journal = "Journal of Vertebrate Paleontology", url = "https://doi.org/10.1080/02724634.1998.10011048", doi = "10.1080/02724634.1998.10011048", number = "1", openalex = "W1999491069", pages = "237-241", volume = "18", references = "doi101007978146122784737, doi101016030096299290314g, doi10108002724634198810011708, doi101111j109636421973tb00786x, doi101111j109636421984tb00544x, doi101111j1469185x1968tb00966x, doi1011300091761319960240399rvdipt23co2, doi105962bhltitle118972, doi105962bhltitle3460, openalexw1539913220" } @article{doi10108002724634199810011048, author = "Cifelli, Richard L. and Wible, John R. and Jenkins, Farish A.", title = "Triconodont mammals from the Cloverly Formation (Lower Cretaceous), Montana and Wyoming", year = "1998", journal = "Journal of Vertebrate Paleontology", abstract = "(1998). Triconodont mammals from the Cloverly Formation (Lower Cretaceous), Montana and Wyoming. Journal of Vertebrate Paleontology: Vol. 18, No. 1, pp. 237-241.", url = "https://doi.org/10.1080/02724634.1998.10011048", doi = "10.1080/02724634.1998.10011048", openalex = "W1999491069", references = "doi101007978146122784737, doi101016030096299290314g, doi10108002724634198810011708, doi101111j109636421973tb00786x, doi101111j109636421984tb00544x, doi101111j1469185x1968tb00966x, doi1011300091761319960240399rvdipt23co2, doi105962bhltitle118972, doi105962bhltitle3460, openalexw1539913220" } @article{doi102110jsr68632, author = "Currie, Brian S.", title = "Upper Jurassic-Lower Cretaceous Morrison and Cedar Mountain formations, NE Utah-NW Colorado; relationships between nonmarine deposition and early Cordilleran foreland-basin development", year = "1998", journal = "Journal of Sedimentary Research", abstract = "ABSTRACT Sedimentologic, stratigraphic, and petrologic analysis of the Upper Jurassic-Lower Cretaceous Morrison and Cedar Mountain formations of Utah and Colorado provides information on the timing and nature of early Cordilleran foreland-basin development. The Morrison Formation can be subdivided into three depositional facies assemblages: (1) lower progradational shallow marine, lacustrine, fluvial, and eolian facies deposited during Oxfordian-Kimmeridgian retreat of the Stump-Sundance sea; (2) a middle assemblage containing sandy-gravelly braided fluvial deposits, which are overlain by meandering fluvial channel and overbank facies; and (3) an upper assemblage of laterally stable, low-sinuosity, fluvial channel facies deposited during Tithonian-early Neocomian (?) time. The upper part of this assemblage shows evidence of alteration and early diagenesis related to development of an Early Cretaceous unconformity. The overlying Cedar Mountain Formation is subdivided into two facies assemblages: (1) the Neocomian Buckhorn Conglomerate was deposited by northeast-trending, sandy-gravelly braided rivers that were incised into the underlying Morrison Formation; (2) an upper assemblage containing laterally stable, low-sinuosity, fluvial channel facies deposited during late Neocomian-Albian time. The base of the unit contains a thick calcrete zone that formed during an unconformity following Buckhorn deposition. Morrison and Cedar Mountain formation sandstones contain three petrofacies: a feldspar-rich lower Morrison petrofacies (\%QmFLt = 70, 19, 11), and chert-rich upper Morrison and Buckhorn/Cedar Mountain petrofacies (\%QmFLt = 54, 5, 41 and 69, 4, 27, respectively). Sandstone composition and paleocurrent data indicate a Cordilleran source area composed of Proterozoic, Paleozoic, and Mesozoic sedimentary rocks. The Morrison Formation and Buckhorn Conglomerate were deposited in the back-bulge depozone of the Late Jurassic Cordilleran foreland-basin system and onlapped a flexural forebulge located in central Utah. Late Neocomian eastward migration of the forebulge uplifted areas in eastern Utah, producing an unconformity, while the foredeep in central Utah underwent flexural subsidence. The upper part of the Cedar Mountain Formation represents overfilling of the foredeep and deposition above the forebulge.", url = "https://doi.org/10.2110/jsr.68.632", doi = "10.2110/jsr.68.632", openalex = "W2096453514", references = "doi101111j136521171992tb00050x" } @article{doi101006cres20000242, author = "Tang, Feng and Luo, Zhe‐Xi and Zhou, Zhuo and You, Hai‐Lu and Georgi, Justin A. and Tang, Zhi-lu and Wang, X.-Z.", title = "Biostratigraphy and palaeoenvironment of the dinosaur-bearing sediments in Lower Cretaceous of Mazongshan area, Gansu Province, China", year = "2001", journal = "Cretaceous Research", url = "https://doi.org/10.1006/cres.2000.0242", doi = "10.1006/cres.2000.0242", openalex = "W2150863381", references = "cifelli1998triconodont, doi10108002724634199810011048" } @article{doi1016690883135120010160233mjbabd20co2, author = "Kvale, Erik P. and JOHNSON, A. D. and Mickelson, Debra L. and Keller, Kenneth W. and Furer, L.C. and Archer, Allen W.", title = "Middle Jurassic (Bajocian and Bathonian) Dinosaur Megatracksites, Bighorn Basin, Wyoming, U.S.A", year = "2001", journal = "Palaios", abstract = "Two previously unknown rare Middle Jurassic dinosaur megatracksites are reported from the Bighorn Basin of northern Wyoming in the Western Interior of the United States.These trace fossils occur in carbonate units once thought to be totally marine in origin, and constitute the two most extensive Middle Jurassic dinosaur tracksites currently known in North America.The youngest of these occurs primarily along a single horizon at or near the top of the ''basal member'' of the ''lower'' Sundance Formation, is mid-Bathonian in age, and dates to ϳ167 ma.This discovery necessitates a major change in the paleogeographic reconstructions for Wyoming for this period.The older tracksites occur at multiple horizons within a 1 m interval in the middle part of the Gypsum Spring Formation.This interval is uppermost Bajocian in age and dates to ϳ170 ma.Terrestrial tracks found, to date, have been all bipedal tridactyl dinosaur prints.At least some of these prints can be attributed to theropods.Possible swim tracks of bipedal dinosaurs are also present in the Gypsum Spring Formation.Digitigrade prints dominate the Sundance trackways, with both plantigrade and digitigrade prints being preserved in the Gypsum Spring trackways.The Sundance track-bearing surface locally covers 7.5 square kilometers in the vicinity of Shell, Wyoming.Other tracks occur apparently on the same horizon approximately 25 kilometers to the west, north of the town of Greybull.The Gypsum Spring megatracksite is locally preserved across the same 25 kilometer east-west expanse, with the Gypsum Spring megatracksite more extensive in a north-south direction with tracks occurring locally across a 100 kilometer extent.Conservative estimates for the trackway density based on regional mapping in the Sundance tracksite discovery area near Shell suggests that over 150,000 in situ tracks may be preserved per square kilometer in the Sundance Formation in this area.Comparable estimates have not been made for other areas.Similarities between the two megatracksites include their formation and preservation in upper intertidal to supratidal sediments deposited under at least seasonally arid conditions.Microbial mat growth on the ancient tidal flats apparently initiated the preservation of these prints.", url = "https://doi.org/10.1669/0883-1351(2001)016<0233:mjbabd>2.0.co;2", doi = "10.1669/0883-1351(2001)016<0233:mjbabd>2.0.co;2", openalex = "W2179114768", references = "doi101111j136530911988tb01248x" } @phdthesis{openalexw2188730773, author = "Wilborn, Brooke K.", title = "Two New Dinosaur Bonebeds From the Late Jurassic Morrison Formation, Bighorn Basin, Wy: an Analysis of the Paleontology and Stratigraphy", year = "2001", booktitle = "VTechWorks (Virginia Tech)", abstract = "Vertebrate fossils have been discovered at several locations in the Bighorn Basin (Wyoming). The Virginia Museum of Natural History's (VMNH) digsite is located in the eastern part of the Bighorn Basin, in the Coyote Basin. Many scientists have worked within these basins trying to describe the stratigraphy. One question specifically asked is where the boundary between the Morrison Fm. (Jurassic) and the Cloverly Fm. (Cretaceous) lies. This new study attempted to show if the current method (Kvale, 1986) of determining the boundary is appropriate. The stratigraphy of the area was examined using Kvale, 1986, Ostrom, 1970, and Moberly, 1960's work in order to see which model was more robust. The fossils in the VMNH digsite were used to supplement the stratigraphic data in determining the age of specific beds. All of Ostrom's units were identified throughout the study area. There is some doubt as to whether the units would be acceptable outside of the Coyote Basin because of laterally discontinuity. Nevertheless, his description of units is satisfactory for the study area, and is more appropriate than other methods. The geologic age of the dinosaurs uncovered in the VMNH quarry is in agreement with the age determined stratigraphically. The VMNH site is below Ostrom's Unit II, which would place it in the Late Jurassic. The determination of the Jurassic/Cretaceous stratigraphic boundary has not been resolved. However, since the Pryor Conglomerate member of the Cloverly Fm. can be identified throughout this area, it is proposed as the Morrison Fm./Cloverly Fm. boundary.", openalex = "W2188730773", references = "doi101016s0016699594802173, doi101029ft322p0008, doi10103819221, doi10103821872, doi101130001676061960711137mcasmf20co2, doi1023072406913, doi1023073514548, doi105860choice376291, kvaleNonepaleoenvironments, openalexw3153867697, openalexw566013788" } @article{doi101086342626, author = "Currie, Brian S.", title = "Structural Configuration of the Early Cretaceous Cordilleran Foreland‐Basin System and Sevier Thrust Belt, Utah and Colorado", year = "2002", journal = "The Journal of Geology", abstract = "Stratigraphic and provenance data from Lower Cretaceous rocks in Utah and Colorado and structural evidence from the Sevier belt in west‐central Utah allow recognition of the ties between early thrust‐belt evolution and foreland‐basin system development. Regional isopach patterns of Lower Cretaceous strata define foreland‐basin system depozones. Lower Cretaceous strata in west‐central Utah that thicken westward from ∼100 m to ∼1.2 km were deposited within the flexurally subsiding foredeep depozone. Correlative units in eastern Utah and western Colorado ∼100 m thick were deposited in the back‐bulge depozone. These thickness trends indicate the Lower Cretaceous foreland‐basin system consisted of a foredeep ∼100–180 km wide and forebulge ∼260–460 km wide. A computer‐generated flexural model of the foreland‐basin system produces a reasonable match of the observed basin geometry using a 400‐km‐wide load with a maximum elevation of 2.5 km located in western Utah. The load used in the model is similar to restored, balanced structural cross sections of the Sevier thrust belt that indicate thrust loads associated with the Canyon Range and Pavant thrusts were at the same location and of similar magnitude during Early Cretaceous time.", url = "https://doi.org/10.1086/342626", doi = "10.1086/342626", openalex = "W2094290315", references = "doi102110pec95520097" } @article{doi1016710272463420020220286lftlca20co2, author = "Nydam, Randall L. and Cifelli, Richard L.", title = "Lizards from the Lower Cretaceous (Aptian–Albian) Antlers and Cloverly Formations", year = "2002", journal = "Journal of Vertebrate Paleontology", abstract = "Abstract Recent discoveries from the Aptian–Albian Antlers (Oklahoma) and Cloverly (Montana, Wyoming) formations provide significant additions to the Early Cretaceous record of lizards in North America. The lizards from the Antlers Formation include two teiids (one named), an anguimorphan, and a series of fragmentary jaws with “paramacellodid”-like teeth. The lizards from the Cloverly Formation include a new species of Paramacellodus and many indeterminate jaw fragments. The apparent lack of shared lizard taxa between the two units calls into question their temporal equivalence, which is based on similarity of dinosaur taxa. Although apparently distinct, the lizard faunas of both units are very similar to that of the Late Jurassic Morrison Formation in being composed primarily of “paramacellodid” or “paramacellodid”-like taxa. It appears that there was a period of relative stasis in the evolution of lizards in North America between the Late Jurassic and Aptian–Albian, paralleling a similar trend in Europe between the Late Jurassic and the Barremian (or later). Reported lizards from the Aptian–Albian of Mongolia present a level of taxonomic diversity much different than that of the same time period in Oklahoma, Montana, and Wyoming, but more like that of the Late Cretaceous of North America, suggesting that taxonomic groups common to the Late Cretaceous and Tertiary occurred earlier in Asia than in North America.", url = "https://doi.org/10.1671/0272-4634(2002)022[0286:lftlca]2.0.co;2", doi = "10.1671/0272-4634(2002)022[0286:lftlca]2.0.co;2", openalex = "W2136137817", references = "cifelli1998triconodont, doi101016019566719190005w, doi101017s009483730002131x, doi10108002724634198410011989, doi10108002724634199810011048, doi101086273307, doi1011111475498300083, doi1034191mp991, doi105962bhltitle4911, openalexw1535663436, openalexw1826760900, openalexw657437657" } @article{doi101016jsedgeo200709001, author = "Elliott, William S. and Suttner, Lee J. and Pratt, Lisa M.", title = "Tectonically induced climate and its control on the distribution of depositional systems in a continental foreland basin, Cloverly and Lakota Formations (Lower Cretaceous) of Wyoming, U.S.A.", year = "2007", journal = "Sedimentary Geology", url = "https://doi.org/10.1016/j.sedgeo.2007.09.001", doi = "10.1016/j.sedgeo.2007.09.001", openalex = "W2008831534", references = "doi102110pec95520097" } @article{doi104202app20080102, author = "Sereno, Paul C. and Brusatte, Stephen L.", title = "Basal Abelisaurid and Carcharodontosaurid Theropods from the Lower Cretaceous Elrhaz Formation of Niger", year = "2008", journal = "Acta Palaeontologica Polonica", abstract = "We report the discovery of basal abelisaurid and carcharodontosaurid theropods from the mid Cretaceous (Aptian-Albian, ca. 112 Ma) Elrhaz Formation of the Niger Republic. The abelisaurid, Kryptops palaios gen. et sp. nov., is represented by a single individual preserving the maxilla, pelvic girdle, vertebrae and ribs. Several features, including a maxilla textured externally by impressed vascular grooves and a narrow antorbital fossa, clearly place Kryptops palaios within Abelisauridae as its oldest known member. The carcharodontosaurid, Eocarcharia dinops gen. et sp. nov., is represented by several cranial bones and isolated teeth. Phylogenetic analysis places it as a basal carcharodontosaurid, similar to Acrocanthosaurus and less derived than Carcharodontosaurus and Giganotosaurus. The discovery of these taxa suggests that large body size and many of the derived cranial features of abelisaurids and carcharodontosaurids had already evolved by the mid Cretaceous. The presence of a close relative of the North American genus Acrocanthosaurus on Africa suggests that carcharodontosaurids had already achieved a trans-Tethyan distribution by the mid Cretaceous.", url = "https://doi.org/10.4202/app.2008.0102", doi = "10.4202/app.2008.0102", openalex = "W2068353031", references = "doi101002ara20206, doi101016004019519190231g, doi101017cbo9780511536045, doi101017s0016756804000330, doi101029jb084ib11p05973, doi10108002724634199710011027, doi101086273307, doi10113008137233291, doi1016710272463420020220460ancroc20co2, doi101671027246342003231apfast20co2, doi10167102724634200727127tpasom20co2, doi1016710272463420072732caomct20co2, doi1034191b109, doi103998mpub9690664, doi105281zenodo16171435, doi105281zenodo4664674, doi105281zenodo5376792, openalexw2173200745, openalexw2989049194" } @article{doi101016jpalaeo200906004, author = "Britt, Brooks B. and Eberth, David A. and Scheetz, Rod D. and Greenhalgh, Brent W. and Stadtman, Kenneth L.", title = "Taphonomy of debris-flow hosted dinosaur bonebeds at Dalton Wells, Utah (Lower Cretaceous, Cedar Mountain Formation, USA)", year = "2009", journal = "Palaeogeography Palaeoclimatology Palaeoecology", url = "https://doi.org/10.1016/j.palaeo.2009.06.004", doi = "10.1016/j.palaeo.2009.06.004", openalex = "W1979079282", references = "doi1010160278416583900089, doi1010160305440388900817, doi101017s0094837300005820, doi101038319768a0, doi10129879781933789439, doi102110palo2003p0322, doi102113gsrocky8specialpaper11, doi1023072802289, doi105860choice300309, doi105860choice393984, doi105962bhlpart22969, doi107208chicago97802267237300010001, openalexw2989049194, ostrom2020stratigraphy" } @article{doi101016jearscirev201005001, author = "Sames, Benjamin and Cifelli, Richard L. and Schudack, Michael", title = "The nonmarine Lower Cretaceous of the North American Western Interior foreland basin: New biostratigraphic results from ostracod correlations and early mammals, and their implications for paleontology and geology of the basin—An overview", year = "2010", journal = "Earth-Science Reviews", url = "https://doi.org/10.1016/j.earscirev.2010.05.001", doi = "10.1016/j.earscirev.2010.05.001", openalex = "W2069443416", references = "doi102110pec95520097" } @article{doi104202app20100073, author = "Taylor, Michael P. and Wedel, Mathew J. and Cifelli, Richard L.", title = "A New Sauropod Dinosaur from the Lower Cretaceous Cedar Mountain Formation, Utah, USA", year = "2011", journal = "Acta Palaeontologica Polonica", abstract = "Brontomerus mcintoshi is a new genus and species of sauropod dinosaur from the Hotel Mesa Quarry in Grand County, Utah, USA, in the upper part of the Ruby Ranch Member (Aptian-Albian) of the Lower Cretaceous Cedar Mountain Formation. It is known from at least two fragmentary specimens of different sizes. The type specimen is OMNH 66430, the left ilium of a juvenile individual; tentatively referred specimens include a crushed presacral centrum, a complete and well-preserved mid-to-posterior caudal vertebra, the partial centrum of a distal caudal vertebra, a complete pneumatic anterior dorsal rib from the right side, the nearly complete left scapula of a much larger, presumably adult, individual, and two partial sternal plates. Brontomerus is diagnosed by five autapomorphies of the type specimen: preacetabular lobe 55\% of total ilium length, longer than in any other sauropod; preacetabular lobe directed anterolaterally at 30 o to the sagittal, but straight in dorsal view and vertically oriented; postacetabular lobe reduced to near absence; ischiadic peduncle reduced to very low bulge; ilium proportionally taller than in any other sauropod, 52\% as high as long. In a phylogenetic analysis, Brontomerus was recovered as a camarasauromorph in all most parsimonious trees, but with uncertain position within that clade. The large preacetabular lobe of the ilium anchored powerful protractor and abductor muscles, but precise interpretation is impossible without functionally related elements such as femora and proximal caudal vertebrae. Brontomerus is the eighth sauropod genus named from the Early Cretaceous of North America, and more remain to be described: North American sauropod diversity did not decline catastrophically at the end of the Jurassic as often assumed. The most striking differences between Late Jurassic and Early Cretaceous sauropod faunas in North America is that the former are abundant and dominated by diplodocids, whereas the latter are comparatively scarce-though still diverse-and dominated by macronarians.", url = "https://doi.org/10.4202/app.2010.0073", doi = "10.4202/app.2010.0073", openalex = "W2148059335", references = "doi101016jpalaeo200906004" } @article{doi101080027246342012671204, author = "D’Emic, Michael D. and Foreman, Brady Z.", title = "The beginning of the sauropod dinosaur hiatus in North America: insights from the Lower Cretaceous Cloverly Formation of Wyoming", year = "2012", journal = "Journal of Vertebrate Paleontology", abstract = "ABSTRACT We redescribe and present newly excavated sauropod material from the Lower Cretaceous Cloverly Formation of Wyoming that we refer to the titanosauriform Sauroposeidon proteles. In contrast to previous hypotheses that it was a brachiosaurid, we assert that Sauroposeidon is a member of the Somphospondyli on the basis of numerous features. Thus, the mid-Cretaceous disappearance of sauropods from the North American fossil record concerned both brachiosaurids and somphospondylans. We find claims for titanosaurs in the Early Cretaceous of North America to be unsubstantiated. The latest register of Sauroposeidon and other Early Cretaceous North American sauropods (before the ‘sauropod hiatus’) occurs in or below the coastal units marking transgression of the Western Interior Seaway, whereas many ecologically disparate dinosaur groups are present both below and above this boundary in the same geologic units that sauropods are found in. The presence of these through-ranging groups with sauropods before and after sauropod absence suggests that appropriate sauropod-bearing environments were present into the Late Cretaceous, implying that the disappearance of sauropods is not attributable to taphonomic or sampling bias. Furthermore, field observations of the Cloverly Formation indicate that Cretaceous pre-hiatus sauropods inhabited near-coastal environments, which were abundant in the western United States well after the start of the hiatus. The start of the sauropod hiatus is interpreted as the result of a genuine continent-wide extinction, coincident with the appearance of (and perhaps attributable to competition with) advanced ornithischian herbivores, decrease in habitat due to the incursion of the Western Interior Seaway, or both.", url = "https://doi.org/10.1080/02724634.2012.671204", doi = "10.1080/02724634.2012.671204", openalex = "W2075903152", references = "doi101017s0094837300005820, doi101046j10963642200200029x, doi10108002724634199810011115, doi10108002724634199910011178, doi101126science23547931156, doi102113gsrocky8specialpaper11, doi102475ajss319111253, doi105860choice393984, openalexw1601939319, openalexw3215057009" } @article{doi101080147720192012667446, author = "D’Emic, Michael D.", title = "Revision of the sauropod dinosaurs of the Lower Cretaceous Trinity Group, southern USA, with the description of a new genus", year = "2012", journal = "Journal of Systematic Palaeontology", abstract = "Early Cretaceous sauropods were among the first dinosaurs discovered in North America, but several aspects of their taxonomy and evolution remain poorly understood. Much of this ambiguity stems from lack of anatomical overlap among taxa and the 125-year-long taxonomic confusion surrounding the sauropods Astrodon and Pleurocoelus. New discoveries have begun to remedy the first problem, but a lack of autapomorphies in their holotypes and skeletal associations among their hypodigms renders Astrodon johnstoni, Pleurocoelus altus and Pleurocoelus nanus nomina dubia. Herein I examine the affinities of sauropods from the Trinity Group of Texas and Oklahoma previously referred to as ‘Pleurocoelus’ or ‘Astrodon’. Some of this material currently comprises the genera Paluxysaurus and Sauroposeidon from laterally equivalent strata in Texas and Oklahoma, respectively. Although representative individuals of Paluxysaurus are only two-thirds the size of Sauroposeidon, bone histology of Paluxysaurus indicates that the individuals from the type locality were not near adult size. The similar provenance, lack of morphological differences, and shared unique features support referral of Paluxysaurus to Sauroposeidon. Other sauropod remains from the Trinity Group are not referable to ‘Pleurocoelus’, ‘Astrodon’ or Sauroposeidon. Some of these remains comprise the holotype of Astrophocaudia slaughteri gen. et sp. nov., a basal titanosauriform diagnosed by a hyposphene–hypantrum system in the caudal vertebrae. A sauropod hind limb previously referred to ‘Pleurocoelus’ is instead referable to Cedarosaurus weiskopfae based on shared features of the pes. Cladistic analysis indicates that Astrophocaudia and Sauroposeidon are members of Somphospondyli, whereas Cedarosaurus is a brachiosaurid. The Trinity Group of Texas and laterally equivalent Antlers Formation of Oklahoma exhibit similar dinosaur faunas at the generic and specific levels to the Cloverly Formation of Wyoming. This homogeneity with respect to latitude stands in marked contrast to the latitudinal variation in dinosaur communities that developed later in the Cretaceous. http://zoobank.org/urn:lsid:zoobank.org:pub:FE82D372-7ADA-4870-9572-3A3F607D39CE", url = "https://doi.org/10.1080/14772019.2012.667446", doi = "10.1080/14772019.2012.667446", openalex = "W2022338877", references = "doi101080027246342012671204, doi1016710272463420020220286lftlca20co2" } @article{doi101080027246342012717567, author = "Oreska, Matthew P. J. and Carrano, Matthew T. and Dzikiewicz, Katherine M.", title = "Vertebrate paleontology of the Cloverly Formation (Lower Cretaceous), I: faunal composition, biogeographic relationships, and sampling", year = "2013", journal = "Journal of Vertebrate Paleontology", abstract = "ABSTRACT The vertebrate fauna of the Cloverly Formation has been studied for more than 75 years, but remains poorly sampled and incompletely understood. We undertook an extensive survey of the formation that resulted in the discovery of several new, highly productive vertebrate microfossil bonebeds (VMBs). Comprehensive sampling of these and other sites has nearly doubled the known vertebrate diversity of the Cloverly Formation. In addition to the comparatively well-known dinosaurs, this augmented faunal list includes hybodontoid sharks, numerous bony fishes, three lissamphibian lineages, lizards, multiple crocodylians, and several new mammal occurrences. The known Cloverly vertebrate fauna now more closely resembles those of other late Early Cretaceous formations in North America, indicating broad similarities across wide geographic areas at this time. In addition, this work underscores the important role VMBs can play in areas previously studied primarily through surface prospecting and quarrying, especially for assessing paleoecology and species diversity.", url = "https://doi.org/10.1080/02724634.2012.717567", doi = "10.1080/02724634.2012.717567", openalex = "W1977535708", references = "cifelli1998triconodont, doi10100797814684216682, doi101007bf00344966, doi101016jcretres200802004, doi101038114085a0, doi10108002724634199810011048, doi101080027246342012671204, doi101086273307, doi101093nqs5vi146318i, doi101098rstb19940091, doi1016660094837336180, doi102110pec95520097, doi102475ajss319111253, doi105281zenodo16171435, doi107312kiel11918, openalexw2246336267, openalexw3215057009, sánchezhernández2007dinosaurs" } @article{doi101371journalpone0080405, author = "Kirkland, James I. and Alcalá, Luís and Loewen, Mark A. and Espílez, Eduardo and Mampel, Luis and Wiersma, Jelle P.", title = "The Basal Nodosaurid Ankylosaur Europelta carbonensis n. gen., n. sp. from the Lower Cretaceous (Lower Albian) Escucha Formation of Northeastern Spain", year = "2013", journal = "PLoS ONE", abstract = "Nodosaurids are poorly known from the Lower Cretaceous of Europe. Two associated ankylosaur skeletons excavated from the lower Albian carbonaceous member of the Escucha Formation near Ariño in northeastern Teruel, Spain reveal nearly all the diagnostic recognized character that define nodosaurid ankylosaurs. These new specimens comprise a new genus and species of nodosaurid ankylosaur and represent the single most complete taxon of ankylosaur from the Cretaceous of Europe. These two specimens were examined and compared to all other known ankylosaurs. Comparisons of these specimens document that Europelta carbonensis n. gen., n. sp. is a nodosaur and is the sister taxon to the Late Cretaceous nodosaurids Anoplosaurus, Hungarosaurus, and Struthiosaurus, defining a monophyletic clade of European nodosaurids- the Struthiosaurinae.", url = "https://doi.org/10.1371/journal.pone.0080405", doi = "10.1371/journal.pone.0080405", openalex = "W2090263554", references = "doi101007bf02860849, doi101016b9780444594259000275, doi101016s0016699580800386, doi1010291999pa900040, doi10102994pa00258, doi10108002724634199510011230, doi101086407120, doi101098rspl18870117, doi101098rsta20031240, doi101127njgpm19831983141, doi1011440016764903087, doi1016660094837320050310291teafot20co2, doi102307jctvxkn7tk, doi103732ajb0900346, olson1972stratigraphy, openalexw1496509561, openalexw3215057009" } @article{doi101371journalpone0112055, author = "Farke, Andrew A. and Maxwell, W. Desmond and Cifelli, Richard L. and Wedel, Mathew J.", title = "A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia", year = "2014", journal = "PLoS ONE", abstract = "The fossil record for neoceratopsian (horned) dinosaurs in the Lower Cretaceous of North America primarily comprises isolated teeth and postcrania of limited taxonomic resolution, hampering previous efforts to reconstruct the early evolution of this group in North America. An associated cranium and lower jaw from the Cloverly Formation (?middle-late Albian, between 104 and 109 million years old) of southern Montana is designated as the holotype for Aquilops americanus gen. et sp. nov. Aquilops americanus is distinguished by several autapomorphies, including a strongly hooked rostral bone with a midline boss and an elongate and sharply pointed antorbital fossa. The skull in the only known specimen is comparatively small, measuring 84 mm between the tips of the rostral and jugal. The taxon is interpreted as a basal neoceratopsian closely related to Early Cretaceous Asian taxa, such as Liaoceratops and Auroraceratops. Biogeographically, A. americanus probably originated via a dispersal from Asia into North America; the exact route of this dispersal is ambiguous, although a Beringian rather than European route seems more likely in light of the absence of ceratopsians in the Early Cretaceous of Europe. Other amniote clades show similar biogeographic patterns, supporting an intercontinental migratory event between Asia and North America during the late Early Cretaceous. The temporal and geographic distribution of Upper Cretaceous neoceratopsians (leptoceratopsids and ceratopsoids) suggests at least intermittent connections between North America and Asia through the early Late Cretaceous, likely followed by an interval of isolation and finally reconnection during the latest Cretaceous.", url = "https://doi.org/10.1371/journal.pone.0112055", doi = "10.1371/journal.pone.0112055", openalex = "W1980567050", references = "doi101080089129632012688589, doi10108010635150701883881, doi101080147720192010488045, doi101098rspl18870117, doi101111j001438202005tb00940x, doi101111j10960031200800217x, doi101126science1116412, doi101126science23547931156, doi10113008137233291, doi10120600030082200635301ydanpc20co2, doi105860choice331556, doi107312kiel11918, longrich2008a, openalexw3215057009" } @article{doi102110pal2013132, author = "McMullen, Sharon K. and Holland, Steven M. and O’Keefe, F. Robin", title = "THE OCCURRENCE OF VERTEBRATE AND INVERTEBRATE FOSSILS IN A SEQUENCE STRATIGRAPHIC CONTEXT: THE JURASSIC SUNDANCE FORMATION, BIGHORN BASIN, WYOMING, U.S.A", year = "2014", journal = "Palaios", abstract = "Previous studies of the sequence stratigraphic distribution of fossils have focused on the record of relatively abundant marine invertebrates. Only a handful of studies have examined how sequence stratigraphic architecture influences the occurrence of vertebrates, particularly large and rare tetrapods. The Jurassic Sundance Formation of the Bighorn Basin, Wyoming, USA, contains a rich suite of invertebrate and vertebrate fossils, including large and rare marine reptiles, and this allows the sequence stratigraphic controls on the distribution of these groups to be compared. The Sundance Formation consists of four depositional sequences, with the lower two being carbonate dominated and the upper two siliciclastic dominated. Two incised valley fills are also present. The presence of multiple depositional sequences and strongly erosional sequence boundaries is the likely cause of the complicated lithostratigraphic nomenclature of the Sundance. Invertebrates (mollusks and echinoderms) in the Sundance conform to well-established patterns of occurrences, including strong facies control and fossil concentrations at maximum flooding surfaces, in the upper portion of parasequences, and within lags overlying sequence boundaries. As expected from their rarity, marine reptiles (ichthyosaurs, plesiosaurs, and pliosaurs) show a weaker connection to sequence stratigraphic architecture. Nonetheless, they do display facies control and are found primarily in offshore mudstone, rather than shoreface and estuarine sandstone. They are also more common at hiatal surfaces, including a zone of concretions at the maximum flooding surface and in lag deposits overlying sequence boundaries. These associations suggest that sequence stratigraphic architecture may be a useful approach for discovery of marine vertebrates and that sequence stratigraphic context should be considered when making paleobiological interpretations of marine vertebrates as well as invertebrates.", url = "https://doi.org/10.2110/pal.2013.132", doi = "10.2110/pal.2013.132", openalex = "W2105175602", references = "doi10108010420940490428823" } @article{doi101139cjes20140200, author = "Eberth, David A.", title = "Origins of dinosaur bonebeds in the Cretaceous of Alberta, Canada", year = "2015", journal = "Canadian Journal of Earth Sciences", abstract = "Upper Cretaceous dinosaur bonebeds are common in Alberta, Canada, and have attracted continuous scientific attention since the 1960s. Since its inception, the Royal Tyrrell Museum of Palaeontology has documented the presence of hundreds of these sites and has been involved directly in the scientific study of many tens. Because many of these bonebeds have been used to address questions about the paleobiology and paleoecology of dinosaurs, questions have arisen about bonebed origins and preservation in the Cretaceous of Alberta. This study of 260 bonebeds delineates broad paleoenvironmental settings and associations, and taphonomic signatures of assemblages as a first step in assessing patterns of dinosaur bonebed origins in the Upper Cretaceous of Alberta. Bonebeds are known predominantly from the Belly River Group and the Horseshoe Canyon, lower St. Mary River, Wapiti, and Scollard formations. In these units, bonebeds are mostly associated with river channel and alluvial wetland settings that were influenced by a subtropical to warm-temperate, monsoonal climate. Most bonebeds formed in response to flooding events capable of killing dinosaurs, reworking and modifying skeletal remains, and burying taphocoenoses. The “coastal-plain-flooding hypothesis,” proposed in 2005, suggested that many bonebeds in the Dinosaur Park Formation formed in response to the effects of recurring coastal-plain floods that submerged vast areas of ancient southern Alberta on a seasonal basis. It remains the best mechanism to explain how many of the bonebeds were formed and preserved at Dinosaur Provincial Park, and here, is proposed as the mechanism that best explains bonebed origins in other Upper Cretaceous formations across central and southern Alberta.", url = "https://doi.org/10.1139/cjes-2014-0200", doi = "10.1139/cjes-2014-0200", openalex = "W1805219736", references = "doi101016jpalaeo200902007, doi101016jpalaeo200906004, doi102110palo2014084, doi1035767gscpgbull444654, doi1035767gscpgbull452155" } @article{carrano2016vertebrate, author = "Carrano, Matthew T. and Oreska, Matthew P. J. and Lockwood, Rowan", title = "Vertebrate paleontology of the Cloverly Formation (Lower Cretaceous), II: Paleoecology", year = "2016", journal = "Journal of Vertebrate Paleontology", url = "https://doi.org/10.1080/02724634.2015.1071265", doi = "10.1080/02724634.2015.1071265", number = "2", openalex = "W2261175596", pages = "e1071265", volume = "36", references = "doi101034j160007062002970210x, doi101038nature01420, doi101038nature06277, doi10108002724634199810011114, doi101111j109583121991tb00548x, doi101111j14610248200400608x, doi101126science2562999, doi1016710272463420010210172dteotr20co2, doi1023071930126, doi105860choice435902" } @article{doi101371journalpone0154218, author = "Mallon, Jordan C. and Ott, Christopher J. and Larson, Peter L. and Iuliano, Edward M. and Evans, David C.", title = "Spiclypeus shipporum gen. et sp. nov., a Boldly Audacious New Chasmosaurine Ceratopsid (Dinosauria: Ornithischia) from the Judith River Formation (Upper Cretaceous: Campanian) of Montana, USA", year = "2016", journal = "PLoS ONE", abstract = "This study reports on a new ceratopsid, Spiclypeus shipporum gen et sp. nov., from the lower Coal Ridge Member of the Judith River Formation in Montana, USA, which dates to \textasciitilde 76 Ma (upper Campanian). The species is distinguished by rugose dorsal contacts on the premaxillae for the nasals, laterally projecting postorbital horncores, fully fused and anteriorly curled P1 and P2 epiparietals, and a posterodorsally projecting P3 epiparietal. The holotype specimen is also notable for its pathological left squamosal and humerus, which show varied signs of osteomyelitis and osteoarthritis. Although the postorbital horncores of Spiclypeus closely resemble those of the contemporaneous 'Ceratops', the horncores of both genera are nevertheless indistinguishable from those of some other horned dinosaurs, including Albertaceratops and Kosmoceratops; 'Ceratops' is therefore maintained as a nomen dubium. Cladistic analysis recovers Spiclypeus as the sister taxon to the clade Vagaceratops + Kosmoceratops, and appears transitional in the morphology of its epiparietals. The discovery of Spiclypeus adds to the poorly known dinosaur fauna of the Judith River Formation, and suggests faunal turnover within the formation.", url = "https://doi.org/10.1371/journal.pone.0154218", doi = "10.1371/journal.pone.0154218", openalex = "W2402671157", references = "doi101016jpalaeo200906004, doi101086684289, doi105281zenodo1048846" } @inproceedings{andforeman2017comparison, author = "Foreman, Brady Z. and D'Emic, Michael D. and Malone, David H. and Craddock, John P.", title = "COMPARISON OF U-PB DETRITAL ZIRCON PROVENANCE BETWEEN UPPER JURASSIC MORRISON FORMATION AND LOWER CRETACEOUS CLOVERLY FORMATION (BIGHORN BASIN, NORTHWEST WYOMING, USA)", year = "2017", booktitle = "Geological Society of America Abstracts with Programs", url = "https://doi.org/10.1130/abs/2017am-301724", doi = "10.1130/abs/2017am-301724", openalex = "W2771313173" } @article{doi101017pab201637, author = "Rogers, Raymond R. and Carrano, Matthew T. and Rogers, Kristina A. Curry and Perez, Magaly and Regan, Anik", title = "Isotaphonomy in concept and practice: an exploration of vertebrate microfossil bonebeds in the Upper Cretaceous (Campanian) Judith River Formation, north-central Montana", year = "2017", journal = "Paleobiology", abstract = "Abstract Vertebrate microfossil bonebeds (VMBs)—localized concentrations of small resilient vertebrate hard parts—are commonly studied to recover otherwise rarely found small-bodied taxa, and to document relative taxonomic abundance and species richness in ancient vertebrate communities. Analyses of taphonomic comparability among VMBs have often found significant differences in size and shape distributions, and thus considered them to be non-isotaphonomic. Such outcomes of “strict” statistical tests of isotaphonomy suggest discouraging limits on the potential for broad, comparative paleoecological reconstruction using VMBs. Yet it is not surprising that sensitive statistical tests highlight variations among VMB sites, especially given the general lack of clarity with regard to the definition of “strict” isotaphonomic comparability. We rigorously sampled and compared six VMB localities representing two distinct paleoenvironments (channel and pond/lake) of the Upper Cretaceous Judith River Formation to evaluate biases related to sampling strategies and depositional context. Few defining distinctions in bioclast size and shape are evident in surface collections, and most site-to-site comparisons of sieved collections are indistinguishable (p ≤0.003). These results provide a strong case for taphonomic equivalence among the majority of Judith River VMBs, and bode well for future studies of paleoecology, particularly in relation to investigations of faunal membership and community structure in Late Cretaceous wetland ecosystems. The taphonomic comparability of pond/lake and channel-hosted VMBs in the Judith River Formation is also consistent with a formative model that contends that channel-hosted VMBs were reworked from pre-existing pond/lake assemblages, and thus share taphonomic history.", url = "https://doi.org/10.1017/pab.2016.37", doi = "10.1017/pab.2016.37", openalex = "W2589812560", references = "carrano2016vertebrate, doi101006cres19941022, doi10100797814899503456, doi101016003101829190016k, doi101017s0094837300004929, doi101038142234b0, doi10108001621459196110482090, doi101086684289, doi101111j13652745200901566x, doi10166600948373200026103tap20co2, doi1023072800758, doi105281zenodo1048846, doi105860choice300309, openalexw2294506137, openalexw2474977981" } @article{doi1026879847, author = "Frederickson, Joseph and Lipka, Thomas R. and Cifelli, Richard L.", title = "Faunal composition and paleoenvironment of the Arundel Clay (Potomac Formation; Early Cretaceous), Maryland, USA", year = "2018", journal = "Palaeontologia Electronica", abstract = "The Arundel Clay facies of the Potomac Group represents one of the few Lower Cretaceous vertebrate-bearing deposits in the Atlantic coastal plain. Vertebrate fossils from this unit have been known for more than 150 years, but thus far formal descriptions have mainly concentrated on its dinosaurs and mammals. Herein, we eport on a moderately diverse faunal assemblage (USNM 41614) from Dinosaur Park in Prince Georges County, Maryland. This assemblage is represented by 306 disarticulated macro-and microfossils that largely consist of teeth and scales (89\%). This vertebrate fauna includes two species of hybodont sharks, multiple semionotid fishes, one species of lungfish, three species of turtle, three families of neosuchian crocodilians, six species of dinosaurs, and two species of mammals. Combined with other historical collections from this unit, these new additions to the fauna show that the Arundel was a far more robust and diverse ecosystem than previously envisaged, broadly similar in composition to contemporaneous units of western North America. The Arundel assemblage differs, however, from those in many other Lower Cretaceous sites in that it is dominated numerically by Hybodus and goniopholidid crocodylomorphs, which together comprise 58\% of catalogued specimens. Similarly, this sample entirely lacks lissamphibians and lepidosaurs. Traditionally, the Arundel has been interpreted as being of fluvial origin, deposited in a freshwater system of stranded channels or oxbows. Based on faunal composition, together with published geological and sedimentological evidence, we propose that at least some of the Arundel facies was deposited in close proximity to the Atlantic Ocean.", url = "https://doi.org/10.26879/847", doi = "10.26879/847", openalex = "W2889032821", references = "doi101017jpa2016131, doi10108002724634199810011114, doi101098rspl18870117, doi101146annurevearth042711105313, doi1023071374076, doi102475ajss321125417, doi105281zenodo1040383, doi105281zenodo16171435, doi105860choice434681, doi105860choice435902, doi105962bhltitle70395, openalexw1847672611" } @article{doi107717peerj5883, author = "Avrahami, Haviv M. and Gates, Terry A. and Heckert, Andrew B. and Makovicky, Peter J. and Zanno, Lindsay E.", title = "A new microvertebrate assemblage from the Mussentuchit Member, Cedar Mountain Formation: insights into the paleobiodiversity and paleobiogeography of early Late Cretaceous ecosystems in western North America", year = "2018", journal = "PeerJ", abstract = "The vertebrate fauna of the Late Cretaceous Mussentuchit Member of the Cedar Mountain Formation has been studied for nearly three decades, yet the fossil-rich unit continues to produce new information about life in western North America approximately 97 million years ago. Here we report on the composition of the Cliffs of Insanity (COI) microvertebrate locality, a newly sampled site containing perhaps one of the densest concentrations of microvertebrate fossils yet discovered in the Mussentuchit Member. The COI locality preserves osteichthyan, lissamphibian, testudinatan, mesoeucrocodylian, dinosaurian, metatherian, and trace fossil remains and is among the most taxonomically rich microvertebrate localities in the Mussentuchit Member. To better refine taxonomic identifications of isolated theropod dinosaur teeth, we used quantitative analyses of taxonomically comprehensive databases of theropod tooth measurements, adding new data on theropod tooth morphodiversity in this poorly understood interval. We further provide the first descriptions of tyrannosauroid premaxillary teeth and document the earliest North American record of adocid remains, extending the appearance of this ancestrally Asian clade by 5 million years in western North America and supporting studies of pre-Cenomaninan Laurasian faunal exchange across Beringia. The overabundance of mesoeucrocodylian remains at the COI locality produces a comparatively low measure of relative biodiversity when compared to other microvertebrate sites in the Mussentuchit Member using both raw and subsampling methods. Much more microvertebrate research is necessary to understand the roles of changing ecology and taphonomy that may be linked to transgression of the Western Interior Seaway or microhabitat variation.", url = "https://doi.org/10.7717/peerj.5883", doi = "10.7717/peerj.5883", openalex = "W2901412058", references = "doi101002ar23592, doi101017pab201637, doi101371journalpone0093190" } @article{demic2019chronostratigraphic, author = "D'Emic, Michael D. and Foreman, Brady Z. and Jud, Nathan A. and Britt, Brooks B. and Schmitz, Mark and Crowley, James L.", title = "Chronostratigraphic Revision of the Cloverly Formation (Lower Cretaceous, Western Interior, USA)", year = "2019", journal = "Bulletin of the Peabody Museum of Natural History", url = "https://doi.org/10.3374/014.060.0101", doi = "10.3374/014.060.0101", number = "1", openalex = "W2932600392", pages = "3", volume = "60", references = "carrano2016vertebrate, doi1010160016703773902135, doi101016jchemgeo200503011, doi101016jepsl200909013, doi101016jgloplacha201312007, doi1010292007gc001805, doi101086622567, doi101103physrevc41889, doi1018814epiiugs2013v36i3002, doi102110pec95520097, doi102475ajs3042105, openalexw2912219260" } @article{doi101017jpa201895, author = "Herne, Matthew and Nair, Jay P. and Evans, Alistair R. and Tait, Alan", title = "New small-bodied ornithopods (Dinosauria, Neornithischia) from the Early Cretaceous Wonthaggi Formation (Strzelecki Group) of the Australian-Antarctic rift system, with revision of Qantassaurus intrepidus Rich and Vickers-Rich, 1999", year = "2019", journal = "Journal of Paleontology", abstract = "Abstract The Flat Rocks locality in the Wonthaggi Formation (Strzelecki Group) of the Gippsland Basin, southeastern Australia, hosts fossils of a late Barremian vertebrate fauna that inhabited the ancient rift between Australia and Antarctica. Known from its dentary, Qantassaurus intrepidus Rich and Vickers-Rich, 1999 has been the only dinosaur named from this locality. However, the plethora of vertebrate fossils collected from Flat Rocks suggests that further dinosaurs await discovery. From this locality, we name a new small-bodied ornithopod, Galleonosaurus dorisae n. gen. n. sp. from craniodental remains. Five ornithopodan genera are now named from Victoria. Galleonosaurus dorisae n. gen. n. sp. is known from five maxillae, from which the first description of jaw growth in an Australian dinosaur is provided. The holotype of Galleonosaurus dorisae n. gen. n. sp. is the most complete dinosaur maxilla known from Victoria. Micro-CT imagery of the holotype reveals the complex internal anatomy of the neurovascular tract and antorbital fossa. We confirm that Q. intrepidus is uniquely characterized by a deep foreshortened dentary. Two dentaries originally referred to Q. intrepidus are reassigned to Q.? intrepidus and a further maxilla is referred to cf. Atlascopcosaurus loadsi Rich and Rich, 1989. A further ornithopod dentary morphotype is identified, more elongate than those of Q. intrepidus and Q.? intrepidus and with three more tooth positions. This dentary might pertain to Galleonosaurus dorisae n. gen. n. sp. Phylogenetic analysis recovered Cretaceous Victorian and Argentinian nonstyracosternan ornithopods within the exclusively Gondwanan clade Elasmaria. However, the large-bodied taxon Muttaburrasaurus langdoni Bartholomai and Molnar, 1981 is hypothesised as a basal iguanodontian with closer affinities to dryomorphans than to rhabdodontids. UUID: http://zoobank.org/4af87bb4-b687-42f3-9622-aa806a6b4116", url = "https://doi.org/10.1017/jpa.2018.95", doi = "10.1017/jpa.2018.95", openalex = "W2921822738", references = "doi101080027246342012694385, doi101080027246342013746229, doi1010800272463420161269539, doi1010800311551820181453085, doi1010801477201920171371258, doi101111j10963642201000620x, doi101111pala12236, doi102307jctt1zxz1md6, doi102307jctvxkn7tk, doi105860choice503272, doi107717peerj1523, openalexw575814759" } @article{doi1033740140600101, author = "D’Emic, Michael D. and Foreman, Brady Z. and Jud, Nathan A. and Britt, Brooks B. and Schmitz, Mark D. and Crowley, James L.", title = "Chronostratigraphic Revision of the Cloverly Formation (Lower Cretaceous, Western Interior, USA)", year = "2019", journal = "Bulletin of the Peabody Museum of Natural History", abstract = "The Cloverly Formation is an important geologic unit for understanding the development of North American terrestrial landscapes and ecosystems, but the age of this unit is poorly constrained. We report U–Pb radiometric dates determined by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and chemical abrasion thermal ionization mass spectrometry (CA-TIMS) from euhedral zircons derived from fluvial sandstone and bentonitic claystone. We reanalyzed published biostratigraphic, paleomagnetic, and radiometric datasets, which have generally disregarded younger (late Albian–Cenomanian) ages for the formation. New data reported in this study suggest that deposition of the Cloverly Formation spanned the Valanginian–Cenomanian stages (ca. 140 Ma–98 Ma), a longer time interval than the commonly cited Aptian–Albian depositional timeframe. The lowest member of the Cloverly Formation, the Pryor Conglomerate, was deposited ca. 140–130 Ma in response to the onset of the Sevier Orogeny shedding sediment from the west. The overlying Little Sheep Mudstone Member was deposited ca. 124–109 Ma in a time of low sediment supply. In the mid–late Albian to early Cenomanian (ca. 109–98 Ma), sediment sourced from the east was deposited as the Himes Member and Greybull Sandstone. Following this, the Sykes Mountain Formation began nearshore deposition as the Western Interior Seaway transgressed from the north. Our revised chronostratigraphic framework for the Cloverly Formation is congruent with tectonic subsidence analysis showing a rapid increase in accommodation space in the mid-Albian. We hypothesize that more intensive sampling may yield multiple fossil assemblages within the formation, paralleling its correlates to the south. Furthermore, we hypothesize that some poorly represented taxa will be synonymized with taxa from those same units now that their temporal equivalence has been demonstrated.", url = "https://doi.org/10.3374/014.060.0101", doi = "10.3374/014.060.0101", openalex = "W2932600392", references = "carrano2016vertebrate, doi1010160016703773902135, doi101016jchemgeo200503011, doi101016jepsl200909013, doi101016jgloplacha201312007, doi1010292007gc001805, doi101086622567, doi101103physrevc41889, doi1018814epiiugs2013v36i3002, doi102475ajs3042105, openalexw2912219260" } @book{doi10129879781933789439, author = "Ostrom, John H.", title = "Stratigraphy and Paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin Area, Wyoming and Montana", year = "2020", booktitle = "Yale University Press eBooks", abstract = "Frontmatter -- CONTENTS -- FIGURES -- TABLES -- CHARTS -- PLATES -- LOCALITY MAPS -- ABSTRACT -- 1. INTRODUCTION -- 2. STRATIGRAPHY -- 3. STRATIGRAPHIC DISTRIBUTION OF FOSSIL VERTEBRATES -- 4. SYSTEMATIC PALEONTOLOGY -- 5. FAUNAL COMPARISONS -- 6. AGE OF THE CLOVERLY FORMATION -- REFERENCES CITED -- APPENDIX A: MEASURED SECTIONS -- APPENDIX B: LOCALITY REGISTER AND MAPS", url = "https://doi.org/10.12987/9781933789439", doi = "10.12987/9781933789439", openalex = "W4285658390" } @book{doi102307jctvxkn7tk, author = "Ostrom, John H.", title = "Stratigraphy and Paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin Area, Wyoming and Montana", year = "2020", booktitle = "Yale University Press eBooks", url = "https://doi.org/10.2307/j.ctvxkn7tk", doi = "10.2307/j.ctvxkn7tk", openalex = "W3011999755" } @article{doi105194fr2312020, author = "Joyce, Walter G. and Rollot, Yann and Cifelli, Richard L.", title = "A new species of baenid turtle from the Early Cretaceous Lakota Formation of South Dakota", year = "2020", journal = "Fossil record", abstract = "Abstract. Baenidae is a clade of paracryptodiran turtles known from the late Early Cretaceous to Eocene of North America. The proposed sister-group relationship of Baenidae to Pleurosternidae, a group of turtles known from sediments dated as early as the Late Jurassic, suggests a ghost lineage that crosses the early Early Cretaceous. We here document a new species of paracryptodiran turtle, Lakotemys australodakotensis gen. and sp. nov., from the Early Cretaceous (Berriasian to Valanginian) Lakota Formation of South Dakota based on a poorly preserved skull and two partial shells. Lakotemys australodakotensis is most readily distinguished from all other named Late Jurassic to Early Cretaceous paracryptodires by having a broad, baenid-like skull with expanded triturating surfaces and a finely textured shell with a large suprapygal I that laterally contacts peripheral X and XI and an irregularly shaped vertebral V that does not lap onto neural VIII and that forms two anterolateral processes that partially separate the vertebral IV from contacting pleural IV. A phylogenetic analysis suggests that Lakotemys australodakotensis is a baenid, thereby partially closing the previously noted gap in the fossil record.", url = "https://doi.org/10.5194/fr-23-1-2020", doi = "10.5194/fr-23-1-2020", openalex = "W3006600777", references = "demic2019chronostratigraphic, doi1033740140600101" } @misc{ostrom2020stratigraphy, author = "Ostrom, John H.", title = "Stratigraphy and Paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin Area, Wyoming and Montana", year = "2020", url = "https://doi.org/10.12987/9781933789439", doi = "10.12987/9781933789439", openalex = "W4285658390" } @article{breeden2021the, author = "Breeden, Benjamin T. and Raven, Thomas J. and Butler, Richard J. and Rowe, Timothy B. and Maidment, Susannah C. R.", title = "The anatomy and palaeobiology of the early armoured dinosaur Scutellosaurus lawleri (Ornithischia: Thyreophora) from the Kayenta Formation (Lower Jurassic) of Arizona", year = "2021", journal = "Royal Society Open Science", abstract = "The armoured dinosaurs, Thyreophora, were a diverse clade of ornithischians known from the Early Jurassic to the end of the Cretaceous. During the Middle and Late Jurassic, the thyreophorans radiated to evolve large body size, quadrupedality, and complex chewing mechanisms, and members of the group include some of the most iconic dinosaurs, including the plated Stegosaurus and the club-tailed Ankylosaurus; however, the early stages of thyreophoran evolution are poorly understood due to a paucity of relatively complete remains from early diverging thyreophoran taxa. Scutellosaurus lawleri is generally reconstructed as the earliest-diverging thyreophoran and is known from over 70 specimens from the Lower Jurassic Kayenta Formation of Arizona, USA. Whereas Scutellosaurus lawleri is pivotal to our understanding of character-state changes at the base of Thyreophora that can shed light on the early evolution of the armoured dinosaurs, the taxon has received limited study. Herein, we provide a detailed account of the osteology of Scutellosaurus lawleri, figuring many elements for the first time. Scutellosaurus lawleri was the only definitive bipedal thyreophoran. Histological studies indicate that it grew slowly throughout its life, possessing lamellar-zonal tissue that was a consequence neither of its small size nor phylogenetic position, but may instead be autapomorphic, and supporting other studies that suggest thyreophorans had lower basal metabolic rates than other ornithischian dinosaurs. Faunal diversity of the Kayenta Formation in comparison with other well-known Early Jurassic-aged dinosaur-bearing formations indicates that there was considerable spatial and/or environmental variation in Early Jurassic dinosaur faunas.", url = "https://doi.org/10.1098/rsos.201676", doi = "10.1098/rsos.201676", number = "7", openalex = "W3184028119", volume = "8", references = "doi101016s0037073803001581, doi101017jpa202014, doi101017s1477201907002271, doi10108002724634199610011283, doi101098rspl18870117, doi101126science28454232137, doi101127njgpa210199841, doi101130b264061, doi1012063521, doi101371journalpone0204007, doi105281zenodo16171435, doi105860choice393984, padian1989presence" } @article{doi1010800272463420212003372, author = "Carrano, Matthew T. and Oreska, Matthew P. J. and Murch, Abree and Trujillo, Kelli C. and Chamberlain, Kevin R.", title = "Vertebrate paleontology of the Cloverly Formation (Lower Cretaceous), III: a new species of Albanerpeton, with biogeographic and paleoecological implications", year = "2021", journal = "Journal of Vertebrate Paleontology", abstract = "We describe a new species of the albanerpetontid amphibian Albanerpeton from three localities in the Lower Cretaceous Cloverly Formation of Wyoming, U.S.A. Radiometric dates between ∼111–112 Ma indicate it is slightly younger than A. arthridion from the Antlers Formation. The new species is diagnosed on a pair of fused frontals that possess a unique combination of characters, mixing plesiomorphic features of the internasal process with a more derived overall shape and proportions. Referred material includes premaxillae, maxillae, dentaries, atlantes, ‘axes,’ trunk vertebrae, humeri, and an ilium.Phylogenetic analyses place the new species near the base of Albanerpeton sensu lato but without fully resolving its position. The inclusion of Shirerpeton and Wesserpeton within this clade opens up the possibility that these genera might be incorporated into Albanerpeton, or that a number of species formerly assigned to Albanerpeton might receive new generic assignments. By including several informal species in our analysis, it becomes clear that character distributions are more homoplastic and that past genus typologies are probably less secure. We assign the new species to Albanerpeton conservatively, pending further phylogenetic study.The Cloverly Albanerpeton is found in unambiguously aquatic deposits, suggesting that the animal lived near these settings for at least part of its life. This is a common habitat for Mesozoic albanerpetontids, unlike the karst-dominated, often drier, deposits in which Cenozoic species are typically found. Despite the recent discovery of a probable arboreal species, it is likely that albanerpetontids inhabited a range of habitats throughout their evolutionary history.", url = "https://doi.org/10.1080/02724634.2021.2003372", doi = "10.1080/02724634.2021.2003372", openalex = "W4214830085", references = "carrano2016vertebrate, doi101016jgr201412004, doi101016jtecto201204021, doi101016s0031018203003675, doi10108002724634198210011915, doi101080027246342012717567, doi10108008120090500100077, doi101111cla12160, doi101111j10960031200800217x, doi101126scienceabb6005, doi101371journalpone0189767, doi1016660094837336180, doi1023071933240, doi105860choice325663, doi105860choice461500" } @article{doi1010801477201920211978005, author = "Lockwood, Jeremy A. F. and Martill, David M. and Maidment, Susannah C. R.", title = "A new hadrosauriform dinosaur from the Wessex Formation, Wealden Group (Early Cretaceous), of the Isle of Wight, southern England", year = "2021", journal = "Journal of Systematic Palaeontology", abstract = "A new genus and species of non-hadrosaurid hadrosauriform dinosaur, Brighstoneus simmondsi gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. The new taxon has two autapomorphies, a nasal having a modest nasal bulla with convex sides, and primary and accessory ridges on the lingual aspect of the maxillary crown. The dentary has at least 28 alveolar positions, which is the highest number recorded in an ornithopod with non-parallel sided alveoli, creating a character combination that is unique within Iguanodontia. The hadrosauriform fauna of the Barremian–Aptian Wealden Group on both the Isle of Wight and mainland England has been represented for almost a century by just two taxa, the robust Iguanodon bernissartensis and the more gracile Mantellisaurus atherfieldensis, with referred material often being fragmentary or based on unassociated elements. This discovery increases the known hadrosauriform diversity in England and, together with recent discoveries in Spain, suggests that their diversity in the upper Wealden of Europe was considerably wider than initially realized. This find also has important implications for the validity of the Mantellisaurus atherfieldensis hypodigm, and a reassessment of existing material is suggested.http://zoobank.org/urn:lsid:zoobank.org:pub:31F0D48F-C1DA-406E-A811-1F5937ED19F4", url = "https://doi.org/10.1080/14772019.2021.1978005", doi = "10.1080/14772019.2021.1978005", openalex = "W3211438913", references = "doi101111brv12666, doi101111zoj12193, doi101371journalpone0045712, gates2018a, tsogtbaatar2019a" } @article{doi101111pala12546, author = "Freimuth, William J. and Varricchio, David J. and Brannick, Alexandria L. and Weaver, Lucas N. and Wilson, Gregory P.", title = "Mammal‐bearing gastric pellets potentially attributable to Troodon formosus at the Cretaceous Egg Mountain locality, Two Medicine Formation, Montana, USA", year = "2021", journal = "Palaeontology", abstract = "Abstract Fossil gastric pellets (regurgitalites) have distinct taphonomic characteristics that facilitate inferences of behavioural ecology in deep time, despite their rarity in the fossil record. Using the taphonomic patterns of both extant and fossil small mammals from more recent geologic deposits as a guide, we assess the taphonomy of three unusual multi‐individual aggregates of mammal skeletons from palaeosols at Egg Mountain, a dinosaur nesting locality from the Upper Cretaceous Two Medicine Formation, Montana, USA. One aggregate consists of two individuals of the multituberculate Filikomys primaevus. This specimen is characterized by brecciated crania, articulated postcrania, and an absence of digestive markings, all suggestive of a non‐predatory origin. Two additional aggregates consist of 3 and 11 individuals, respectively, primarily of the marsupialiform Alphadon halleyi. High proportions of crania and indigestible elements (e.g. teeth), extensive disarticulation and breakage, digestive corrosion patterns, and the absence of a phosphatic ground mass are indicative of regurgitalites and align with features of extant prey in diurnal raptor gastric pellets. We interpret these specimens as the oldest known mammal‐bearing regurgitalites. The discrepancy in taphonomic features implies behavioural separation between the two mammalian taxa at the locality. Abundant shed teeth and nesting evidence at the locality favours the non‐avian theropod Troodon formosus as the predator responsible for the regurgitalites, congruent with previous inferences of a small‐bodied prey diet, manipulation of prey during feeding, heightened metabolic processes, and potential nocturnality for this taxon.", url = "https://doi.org/10.1111/pala.12546", doi = "10.1111/pala.12546", openalex = "W3183484889", references = "doi101016jcub201803042, doi101017pab201637, doi101139cjes20200169, doi102110palo2019099, doi103389feart201800252" } @article{doi107717peerj12242, author = "Suarez, Celina and Frederickson, Joseph and Cifelli, Richard L. and Pittman, Jeffrey G. and Nydam, Randall L. and Hunt-Foster, ReBecca and Morgan, Kirsty", title = "A new vertebrate fauna from the Lower Cretaceous Holly Creek Formation of the Trinity Group, southwest Arkansas, USA", year = "2021", journal = "PeerJ", abstract = "We present a previously discovered but undescribed late Early Cretaceous vertebrate fauna from the Holly Creek Formation of the Trinity Group in Arkansas. The site from the ancient Gulf Coast is dominated by semi-aquatic forms and preserves a diverse aquatic, semi-aquatic, and terrestrial fauna. Fishes include fresh- to brackish-water chondrichthyans and a variety of actinopterygians, including semionotids, an amiid, and a new pycnodontiform, Anomoeodus caddoi sp. nov. Semi-aquatic taxa include lissamphibians, the solemydid turtle Naomichelys, a trionychid turtle, and coelognathosuchian crocodyliforms. Among terrestrial forms are several members of Dinosauria and one or more squamates, one of which, Sciroseps pawhuskai gen. et sp. nov., is described herein. Among Dinosauria, both large and small theropods (Acrocanthosaurus, Deinonychus, and Richardoestesia) and titanosauriform sauropods are represented; herein we also report the first occurrence of a nodosaurid ankylosaur from the Trinity Group. The fauna of the Holly Creek Formation is similar to other, widely scattered late Early Cretaceous assemblages across North America and suggests the presence of a low-diversity, broadly distributed continental ecosystem of the Early Cretaceous following the Late Jurassic faunal turnover. This low-diversity ecosystem contrasts sharply with the highly diverse ecosystem which emerged by the Cenomanian. The contrast underpins the importance of vicariance as an evolutionary driver brought on by Sevier tectonics and climatic changes, such as rising sea level and formation of the Western Interior Seaway, impacting the early Late Cretaceous ecosystem.", url = "https://doi.org/10.7717/peerj.12242", doi = "10.7717/peerj.12242", openalex = "W3205493255", references = "demic2019chronostratigraphic, doi1026879847, doi1033740140600101" } @article{doi1010800272463420242316668, author = "Whitebone, S. Amber and Funston, Gregory F. and Currie, Philip J.", title = "An unusual microsite from the Upper Cretaceous Horseshoe Canyon Formation of Alberta, Canada", year = "2023", journal = "Journal of Vertebrate Paleontology", abstract = "The Upper Cretaceous Horseshoe Canyon Formation of Alberta, Canada, is among the best-studied paleoecosystems in North America. However, its microvertebrate paleocommunity structure is relatively poorly known, partly because it lacks the abundant microsites of other Upper Cretaceous deposits of Alberta. An unusual microsite (FTS-2) from the Horsethief Member of the Horseshoe Canyon Formation is described that produces abundant anuran and troodontid material, alongside perinatal material from ornithischians and tyrannosaurs. Anuran specimens representing a minimum of two separate taxa and a metatherian molar suggest that these components of the fauna were more diverse than currently recognized. The assemblage is similar to three other North American sites that produce abundant troodontid teeth alongside perinatal dinosaurs. However, environmental and taphonomic conditions of these sites vary, supporting the notion of mixed biotic and abiotic factors driving the association of troodontids alongside perinates. In part, this may stem from similar nesting preferences between troodontids and other dinosaurs, as material collected from all three sites suggests proximity to troodontid nesting sites. Sites such as FTS-2 are important for revealing the rare and small components of paleoecosystems, and hold promise for revealing interactions between these parts of the fauna.", url = "https://doi.org/10.1080/02724634.2024.2316668", doi = "10.1080/02724634.2024.2316668", openalex = "W4393150755", references = "doi101002ar24199, doi101017pab201637, doi101073pnas1011924108, doi10108002724634199510011271, doi101098rspl18870117, doi101126science28253972241, doi101139cjes20170034, doi101139cjes20200145, doi101139cjes20200169, doi1023071005355, doi1023071374076, doi105281zenodo1040383, doi105281zenodo16171435, doi105281zenodo16435343, doi105962bhltitle106965, openalexw3215057009" } @article{doi101093zoolinneanzlad124, author = "Mocho, Pedro and Escaso, Fernando and Gasulla, José Miguel and Galobart, Àngel and Poza, Begoña and Cubedo, Andrés Santos and Sanz, J. L. and Ortega, Francisco", title = "New sauropod dinosaur from the Lower Cretaceous of Morella (Spain) provides new insights on the evolutionary history of Iberian somphospondylan titanosauriforms", year = "2023", journal = "Zoological Journal of the Linnean Society", abstract = "Abstract A new somphospondylan titanosauriform from the Lower Cretaceous of Spain is described from the remains found at the Sant Antoni de la Vespa site (upper Barremian Arcillas de Morella Formation) located in Morella. Garumbatitan morellensis gen. et sp. nov. is diagnosed by 11 autapomorphies and eight local autapomorphies; and our phylogenetic analyses suggest that Garumbatitan morellensis might correspond to an early-branching somphospondylan. The presence of several somphospondylan traits in Garumbatitan morellensis supports the somphospondylan hypothesis. The phylogenetic distribution of some titanosauriform and somphospondylan novelties in the femur (markedly developed lateral bulge, high shaft eccentricity, linea intermuscularis cranialis, and trochanteric shelf) is discussed. The tarsus and pes of Garumbatitan morellensis are distinctive, being characterized by the loss of the calcaneum, relative slenderness of the metatarsals II, III, and IV when compared to the retracted metatarsals I and V, three pedal phalanges in digit IV, and reduced ungual III. The sauropod fauna of the Iberian Peninsula during the Hauterivian–Aptian shows a complex phylogenetic mosaic, including forms with Laurasian affinities, mainly titanosauriforms (Soriatitan, Garumbatitan, and possibly Tastavinsaurus and Europatitan), and Gondwanan affinities, the rebbachisaurid Demandasaurus. Faunal exchange during the Early Cretaceous between the Europe, North America, East Asia, and Africa is plausible.", url = "https://doi.org/10.1093/zoolinnean/zlad124", doi = "10.1093/zoolinnean/zlad124", openalex = "W4387139168", references = "doi105252geodiversitas2022v44a25" } @article{doi101371journalpone0286042, author = "Zanno, Lindsay E. and Gates, Terry A. and Avrahami, Haviv M. and Tucker, Ryan T. and Makovicky, Peter J.", title = "An early-diverging iguanodontian (Dinosauria: Rhabdodontomorpha) from the Late Cretaceous of North America", year = "2023", journal = "PLoS ONE", abstract = "Intensifying macrovertebrate reconnaissance together with refined age-dating of mid-Cretaceous assemblages in recent decades is producing a more nuanced understanding of the impact of the Cretaceous Thermal Maximum on terrestrial ecosystems. Here we report discovery of a new early-diverging ornithopod, Iani smithi gen. et sp. nov., from the Cenomanian-age lower Mussentuchit Member, Cedar Mountain Formation of Utah, USA. The single known specimen of this species (NCSM 29373) includes a well-preserved, disarticulated skull, partial axial column, and portions of the appendicular skeleton. Apomorphic traits are concentrated on the frontal, squamosal, braincase, and premaxilla, including the presence of three premaxillary teeth. Phylogenetic analyses using parsimony and Bayesian inference posit Iani as a North American rhabdodontomorph based on the presence of enlarged, spatulate teeth bearing up to 12 secondary ridges, maxillary teeth lacking a primary ridge, a laterally depressed maxillary process of the jugal, and a posttemporal foramen restricted to the squamosal, among other features. Prior to this discovery, neornithischian paleobiodiversity in the Mussentuchit Member was based primarily on isolated teeth, with only the hadrosauroid Eolambia caroljonesa named from macrovertebrate remains. Documentation of a possible rhabdodontomorph in this assemblage, along with published reports of an as-of-yet undescribed thescelosaurid, and fragmentary remains of ankylosaurians and ceratopsians confirms a minimum of five, cohabiting neornithischian clades in earliest Late Cretaceous terrestrial ecosystems of North America. Due to poor preservation and exploration of Turonian-Santonian assemblages, the timing of rhabdodontomorph extirpation in the Western Interior Basin is, as of yet, unclear. However, Iani documents survival of all three major clades of Early Cretaceous neornithischians (Thescelosauridae, Rhabdodontomorpha, and Ankylopollexia) into the dawn of the Late Cretaceous of North America.", url = "https://doi.org/10.1371/journal.pone.0286042", doi = "10.1371/journal.pone.0286042", openalex = "W4379739689", references = "demic2019chronostratigraphic, doi101038s4159802219896w, doi1033740140600101, gates2018a" } @article{doi107717peerj15453, author = "Barker, Chris T. and Naish, Darren and Gostling, Neil J.", title = "Isolated tooth reveals hidden spinosaurid dinosaur diversity in the British Wealden Supergroup (Lower Cretaceous)", year = "2023", journal = "PeerJ", abstract = "Isolated spinosaurid teeth are relatively well represented in the Lower Cretaceous Wealden Supergroup of southern England, UK. Until recently it was assumed that these teeth were referable to Baryonyx, the type species (B. walkeri) and specimen of which is from the Barremian Upper Weald Clay Formation of Surrey. British spinosaurid teeth are known from formations that span much of the c. 25 Ma depositional history of the Wealden Supergroup, and recent works suggest that British spinosaurids were more taxonomically diverse than previously thought. On the basis of both arguments, it is appropriate to doubt the hypothesis that isolated teeth from outside the Upper Weald Clay Formation are referable to Baryonyx. Here, we use phylogenetic, discriminant and cluster analyses to test whether an isolated spinosaurid tooth (HASMG G369a, consisting of a crown and part of the root) from a non-Weald Clay Formation unit can be referred to Baryonyx. HASMG G369a was recovered from an uncertain Lower Cretaceous locality in East Sussex but is probably from a Valanginian exposure of the Hastings Group and among the oldest spinosaurid material known from the UK. Spinosaurid affinities are both quantitatively and qualitatively supported, and HASMG G369a does not associate with Baryonyx in any analysis. This supports recent reinterpretations of the diversity of spinosaurid in the Early Cretaceous of Britain, which appears to have been populated by multiple spinosaurid lineages in a manner comparable to coeval Iberian deposits. This work also reviews the British and global records of early spinosaurids (known mainly from dental specimens), and revisits evidence for post-Cenomanian spinosaurid persistence.", url = "https://doi.org/10.7717/peerj.15453", doi = "10.7717/peerj.15453", openalex = "W4378909266", references = "doi105252geodiversitas2022v44a25" } @article{doi1010800272463420242399102, author = "Oreska, Matthew P. J. and DeMar, David G. and Gardner, James D. and Carrano, Matthew T.", title = "Vertebrate paleontology of the Cloverly Formation (Lower Cretaceous), IV: the oldest edentulous frog (Salientia) from Laurasia", year = "2024", journal = "Journal of Vertebrate Paleontology", url = "https://doi.org/10.1080/02724634.2024.2399102", doi = "10.1080/02724634.2024.2399102", openalex = "W4402836180", references = "doi1010800272463420212003372" } @article{doi1010801477201920242346573, author = "Lockwood, Jeremy A. F. and Martill, David M. and Maidment, Susannah C. R.", title = "Comptonatus chasei, a new iguanodontian dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, southern England", year = "2024", journal = "Journal of Systematic Palaeontology", abstract = "A new iguanodontian dinosaur, Comptonatus chasei gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. These strata provide an important record of a critical time in the development of iguanodontian diversity. The specimen, which is described here for the first time, was found and excavated in 2013 and represents the most complete iguanodontian skeleton discovered in the Wealden Group for a century. A new taxon is diagnosed by several autapomorphies found in the neurocranium, teeth, coracoid and other parts of the body, together with a unique suite of characters. These include a dentary with a straight ventral border, and a markedly expanded prepubic blade. These features set it apart from the sympatric Mantellisaurus atherfieldensis, Brighstoneus simmondsi and Iguanodon cf. bernissartensis, increasing the known diversity of this clade in the Barremian–early Aptian of England. http://zoobank.org/urn:lsid:zoobank.org:pub:2F3125A5-BDEF-4835-8829-92104752A86F", url = "https://doi.org/10.1080/14772019.2024.2346573", doi = "10.1080/14772019.2024.2346573", openalex = "W4400439377", references = "doi101111joa13363, doi101371journalpone0045712, doi101371journalpone0175253, doi102307jctt1zxz1md6, doi104202app20110051, gates2018a, tsogtbaatar2019a" } @inproceedings{andjackson2025paleosols, author = "Jackson, Emily and Holland, Steven", title = "Paleosols through time: implications for the paleobiological record of the Lower Cretaceous Cloverly Formation, Bighorn Basin, Wyoming", year = "2025", booktitle = "Geological Society of America Abstracts with Programs", url = "https://doi.org/10.1130/abs/2025am-9197", doi = "10.1130/abs/2025am-9197", openalex = "W4417218195" } @article{doi101017jpa20254, author = "Carrano, Matthew T.", title = "First report of ceratopsians and tyrannosauroids (Dinosauria) in the Newark Canyon Formation (Lower Cretaceous) of Nevada", year = "2025", journal = "Journal of Paleontology", abstract = "Abstract This paper describes three collections of vertebrate fossils from the Lower Cretaceous Newark Canyon Formation of Eureka County, Nevada, made by the United States Geological Survey in 1961. Briefly mentioned in the prior literature, these specimens have gone unstudied for more than sixty years, until their recent transfer to the Smithsonian Institution. Re-examination of the materials reveals the first records of neoceratopsian and tyrannosauroid dinosaurs in the Newark Canyon Formation. In addition to augmenting the known vertebrate fauna from this poorly studied stratum, these occurrences provide important new data on otherwise rare taxa during a time of major faunal transition in North America.", url = "https://doi.org/10.1017/jpa.2025.4", doi = "10.1017/jpa.2025.4", openalex = "W4410244958", references = "doi1026879847" } @article{doi101371journalpone0335893, author = "Botfalvai, Gábor and Csiki‐Sava, Zoltán and Magyar, János and Páll‐Gergely, Barna and Koczó, Levente and Ţabără, Daniel and Konecsni, Gergő and Budai, Soma", title = "Paleontological and paleoecological significance of the oldest highly productive Upper Cretaceous (lowermost Maastrichtian) bonebed of Haţeg Basin (western Romania; Densuş-Ciula Formation)", year = "2025", journal = "PLoS ONE", abstract = "Recent extensive fieldwork in the Densuş-Ciula Formation in Haţeg Basin has led to the discovery of several important high-diversity bonebeds. Among the excavated locations, site K2 is by far the most significant, as based on its stratigraphical position it is considered the oldest known (earliest Maastrichtian) highly diversified vertebrate site in the entire Haţeg Basin, and thus provides a good starting point for paleofaunistic, paleoecological and biostratigraphic comparisons with other similar sites across the Transylvanian area. During this study, detailed sedimentological, palynological, invertebrate- and vertebrate paleontological investigations were conducted to reconstruct the former paleoenvironment and the different depositional processes that allowed the formation of this productive bonebed. More than 800 vertebrate fossils were collected from an approximately 4.75 m2 area of the bonebed horizon of site K2 representing at least 17 species including fish, amphibians, turtles, squamates, crocodyliforms, dinosaurs, pterosaurs and mammals, ranking this site among the most taxonomically diverse ones within the basin. The sedimentological investigation points towards a lacustrine depositional environment in which a high-diversity, multitaxic, multidominant mixed assemblage was accumulated on a flood-related delta due to a sudden drop in transport energy. Based on its stratigraphical position, site K2 represents the oldest vertebrate site within the Haţeg area and suggests a remarkable large-scale faunal stability on the Haţeg Island during the Maastrichtian. The dominant elements of the local fauna were already present in the earliest Maastrichtian, and no significant differences in faunal composition can be detected between this oldest and other, younger vertebrate assemblages of Haţeg Basin, at least at the level of higher taxa. Furthermore, just as the faunal composition, the dominance spectrum of the different taxa has not changed significantly among the Maastrichtian sites of Haţeg Basin.", url = "https://doi.org/10.1371/journal.pone.0335893", doi = "10.1371/journal.pone.0335893", openalex = "W4416078619", references = "doi1010800272463420212003372" } @article{doi103389feart20251497416, author = "Allen, Maximilian L. and Suarez, Marina B. and Adams, Thomas L. and Suarez, Celina", title = "Ecohydrology and paleoenvironment of the Cretaceous (Albian) Cloverly Formation: insights from multi-taxon oxygen isotope analysis of vertebrate phosphates", year = "2025", journal = "Frontiers in Earth Science", abstract = "The Cloverly Formation of Montana and Wyoming preserves abundant nonmarine vertebrate fossils from the mid-Cretaceous, yet its paleoenvironment and faunal niche structure remain poorly understood. We analyzed δ 18 Ο phosphate in over 100 fossil individuals from multiple vertebrate taxa collected from a single microfossil bonebed in Carbon County, Montana.To infer habitat preferences and water-use strategies, we compared δ 18 Ο phosphate values within and across taxa. We reconstructed δ 18 O surface\_water from semi-aquatic reptile values using regressions calibrated with data from modern environments and extant taxa. Using a multi-taxon framework, we estimated warm-season water temperatures from δ 18 O surface\_water and δ 18 Ο phosphate of lepisosteid (gar) scales, then converted these to air temperatures using a modern climate transfer function. δ 18 Ο phosphate values ranged from 9.5‰ to 23.2‰ (VSMOW) and varied across taxa. Aquatic and semi-aquatic groups exhibited lower values than dinosaurian taxa. Our reconstructed mean δ 18 O surface\_water was −7.9‰ (95\% CI: −10.1 to 5.5‰), yielding a warm-season water temperature of 26°C and an air temperature of 24°C. Intertaxon differences reflect niche partitioning and suggest primary isotopic signals are preserved. Unexpectedly high values in Bernissartiid-like neosuchian teeth may indicate greater ecohydrological diversity than previously recognized. Our δ 18 O surface\_water estimate aligns with other Aptian-Albian proxies but exceeds model-based predictions, likely due to outdated assumptions underlying the model. The MAWSAT estimate falls within the upper range of model-data assimilation outputs. These results provide new context for ecological structure in the Cloverly fauna and offer the first quantitative temperature estimate for the Formation, helping to define baseline conditions between the Aptian-Albian Cold Snap and the Cretaceous Thermal Maximum.", url = "https://doi.org/10.3389/feart.2025.1497416", doi = "10.3389/feart.2025.1497416", openalex = "W4410316006", references = "doi1010800272463420212003372" } @article{doi107717peerj19340, author = "Adrian, Brent and Smith, Heather F. and McDonald, Andrew T.", title = "A revised turtle assemblage from the Upper Cretaceous Menefee Formation (New Mexico, North America) with evolutionary and paleobiostratigraphic implications", year = "2025", journal = "PeerJ", abstract = "and multiple trionychid and plastomenid species through the remainder of the Campanian in the San Juan Basin. A cluster analysis of turtle diversity across early-middle Campanian sites in Laramidia shows distributions consistent with latitudinal provinciality in some groups. For instance, derived baenids were restricted to latitudes south of southern Utah, along with marine taxa (bothremydids and protostegids) and pan-kinosternoids. Basin-scale endemism is also suggested by some baenid and trionychid distributions. Otherwise, the turtle fauna of the Menefee most closely resemble those of the similarly-aged Wahweap Fm. in southern Utah, and the Aguja Fm. in the Big Bend area of Texas and Mexico to a lesser extent. The Menefee turtle assemblage is consistent with reconstructed paleoenvironments characteristic of the western shoreline of the Western Interior Seaway. Recurrent cyclothems in these settings shaped the development of fluviodeltaic deposits that preserved distal components of large channels with surrounding floodplains and swamps, along with evidence of freshwater, brackish, and possibly shallow marine influence.", url = "https://doi.org/10.7717/peerj.19340", doi = "10.7717/peerj.19340", openalex = "W4409705461", references = "doi101007s1254202100555w, doi101016jjsames201810005, doi1013065ceae56516bb11d78645000102c1865d, doi103133b1940" } @article{doi101002spp270055, author = "Jansen, Olivier and Garcia, Géraldine and Otero, Olga and Augé, Marc and Gomez, Bernard and Valentin, Xavier", title = "Freshwater amphibians and squamates from Villeveyrac (lower Campanian; Hérault, France): palaeodiversity, palaeoenvironment and implications for the Late Cretaceous palaeobiogeography of the European herpetofauna", year = "2026", journal = "Papers in Palaeontology", abstract = "Abstract The Late Cretaceous witnessed numerous transgression–regression sequences and the onset of a global cooling phase at the start of the Campanian. In the European archipelago, these environmental changes, combined with active plate tectonics, facilitated the formation of ephemeral land bridges that served as dispersal routes for a variety of clades. However, the timing and mechanisms of these dispersals remain poorly understood, notably because of the scarcity of lower Campanian fossil‐bearing continental outcrops. Over the last two decades, the locality of Villeveyrac (Hérault, France) has yielded lower Campanian freshwater deposits, particularly rich in vertebrates and plants. Despite abundant findings, the diversity of amphibians and squamates has been sparsely documented. In this study we identify six amphibian taxa (Albanerpetontidae,?Palaeobatrachidae indet.,?Neobatrachia indet., Batrachosauroididae indet., and two indeterminate anurans) alongside six squamate taxa, which include a pan‐shinisaur lizard, a madtsoiid snake of the genus Herensugea and indeterminate monstersaur,?anguid, iguanomorph and squamate. Six of these 12 taxa, specifically the palaeobatrachid, batrachosauroidid, pan‐shinisaur, madtsoiid, monstersaur and iguanomorph, correspond to the earliest occurrence of their clades in Europe. Additionally, we tentatively document one of the oldest anguids in the world. For each of these groups, we discuss palaeobiogeographical and palaeoenvironmental implications. The amphibian and squamate composition highlights a combination of aquatic, semi‐aquatic and terrestrial features, consistent with other animal and plant remains. The lower Campanian deposits of Villeveyrac are thus interpreted as a floodplain with braided streams, river channels, and surrounding riparian and paludal habitats, under a warm and humid subtropical climate.", url = "https://doi.org/10.1002/spp2.70055", doi = "10.1002/spp2.70055", openalex = "W7125796552", references = "doi1010800272463420212003372, doi1010800891296320211881084, doi1010800891296320222054712" } @misc{kvaleNonepaleoenvironments, author = "Kvale, Erik Peter", title = "Paleoenvironments and tectonic significance of the Upper Jurassic Morrison/Lower Cretaceous Cloverly formations, Bighorn Basin, Wyoming", year = "None", url = "https://doi.org/10.31274/rtd-180813-5735", doi = "10.31274/rtd-180813-5735", openalex = "W290722566", references = "doi1010079783642814983, doi1010160012825277900551, doi101016b9780444408266500078, doi1010970001069419730500000019, doi101111j136530911975tb00290x, doi101111j136530911977tb00128x, doi1011300091761319808543ncrihs20co2, doi10130603b599f416d111d78645000102c1865d, doi10130674d720182b2111d78648000102c1865d, openalexw1912927042" } @misc{solimanNonestratigraphy, author = "Soliman, Hosny El-Desouky Ahmed", title = "Stratigraphy and sedimentology of Lower Cretaceous Sykes Mountain Formation, Bighorn Basin, Wyoming", year = "None", url = "https://doi.org/10.31274/rtd-180813-8886", doi = "10.31274/rtd-180813-8886", openalex = "W797660994", references = "doi1010079783642814983, doi1010160012825277900551, doi1010970001069419730500000019, doi10113000167606196576803masord20co2, doi10113000167606197687725mobmoa20co2, doi10113000167606198293663hssoiv20co2, doi101306d42695672b2611d78648000102c1865d, doi1023073514634, kvaleNonepaleoenvironments, openalexw1528850606, openalexw1912927042" }