@article{pitrat1973vertebrates,
    author = "Pitrat, Charles W.",
    title = "Vertebrates and the Permo-Triassic extinction",
    year = "1973",
    journal = "Palaeogeography, Palaeoclimatology, Palaeoecology",
    url = "https://doi.org/10.1016/0031-0182(73)90011-4",
    doi = "10.1016/0031-0182(73)90011-4",
    number = "4",
    pages = "249-264",
    volume = "14"
}

@misc{pitrat1973vertebrates1,
    author = "Pitrat, C. W",
    title = "Vertebrates and the Permo-Triassic extinction",
    year = "1973",
    howpublished = "Palaeogeography, Palaeoclimatology, Palaeoecology, v. 14, p. 249-264",
    note = "talkorigins\_source = {true}; raw\_reference = {Pitrat, C. W., 1973, Vertebrates and the Permo-Triassic extinction: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 14, p. 249-264.}"
}

@article{schopf1974permotriassic2,
    author = "Schopf, T. J. M",
    title = "Permo-Triassic extinctions",
    year = "1974",
    journal = "relations to sea floor spreading: Journal of Geology, v. 82, p. 129-143",
    note = "talkorigins\_source = {true}; raw\_reference = {Schopf, T. J. M., 1974, Permo-Triassic extinctions: relations to sea floor spreading: Journal of Geology, v. 82, p. 129-143.}"
}

@article{simberloff1974permotriassic3,
    author = "Simberloff, D. S",
    title = "Permo-Triassic extinctions",
    year = "1974",
    journal = "effects of area on biotic equilibrium: Journal of Geology, v. 82, p. 267-274",
    note = "talkorigins\_source = {true}; raw\_reference = {Simberloff, D. S., 1974, Permo-Triassic extinctions: effects of area on biotic equilibrium: Journal of Geology, v. 82, p. 267-274.}"
}

@incollection{olson1982extinctions,
    author = "Olson, Everett C.",
    title = "Extinctions of Permian and Triassic nonmarine vertebrates",
    year = "1982",
    booktitle = "Geological Implications of Impacts of Large Asteroids and Comets on the Earth",
    abstract = "The massive extinction of invertebrate shallow marine organisms during late Permian time and the resurgence of new families during Triassic time are well documented and appear to be related to sharp reduction in the habitat areas of the major groups as shallow sea environments became increasingly reduced. Sharp changes occurred in the terrestrial vertebrates, but the patterns of change were distinctly different and through Permian and Triassic periods occurred four times. The first major decrease in numbers of families took place at the end of early Permian time (the Kungurian-Guadalupian transition). The loss comprised the majority of families and their immediate derivatives that had persisted from the coal measures into the lower Permian. A second sharp decrease of reptilian families took place at the end of Permian time and included primarily therapsid reptiles involved in the therapsid radiation of the middle and upper Permian. A few “advanced” families existed. A third episode of loss of families occurred at the end of Early Triassic time and a fourth at the end of Triassic time. The last involved primarily archosaurian reptiles, which had replaced the therapsids. The changes that took place and the causes of severe decreases in families may be viewed from four perspectives: stochastic events; physical changes extrinsic to the organisms; biological changes, both intrinsic and extrinsic to the organisms; and catastrophic events. The strong tendency toward phyletic attainment of large size clearly played an important role in familial decreases as physical and biological changes and geographic distributions changed. No definitive evidence that catastrophe had any role in any of the familial extinctions exists at present, but that this may have played a role in the loss of families during Permian and Triassic times cannot be fully ruled out.",
    url = "https://doi.org/10.1130/spe190-p501",
    doi = "10.1130/spe190-p501",
    pages = "501-512"
}

@article{doi101098rspb20201125,
    author = "Allen, Bethany J and Wignall, Paul B and Hill, Daniel J and Saupe, Erin E and Dunhill, Alexander M",
    title = "The latitudinal diversity gradient of tetrapods across the Permo-Triassic mass extinction and recovery interval.",
    year = "2020",
    journal = "Proceedings. Biological sciences",
    abstract = "The decline in species richness from the equator to the poles is referred to as the latitudinal diversity gradient (LDG). Higher equatorial diversity has been recognized for over 200 years, but the consistency of this pattern in deep time remains uncertain. Examination of spatial biodiversity patterns in the past across different global climate regimes and continental configurations can reveal how LDGs have varied over Earth history and potentially differentiate between suggested causal mechanisms. The Late Permian-Middle Triassic represents an ideal time interval for study, because it is characterized by large-scale volcanic episodes, extreme greenhouse temperatures and the most severe mass extinction event in Earth history. We examined terrestrial and marine tetrapod spatial biodiversity patterns using a database of global tetrapod occurrences. Terrestrial tetrapods exhibit a bimodal richness distribution throughout the Late Permian-Middle Triassic, with peaks in the northern low latitudes and southern mid-latitudes around 20-40° N and 60° S, respectively. Marine reptile fossils are known almost exclusively from the Northern Hemisphere in the Early and Middle Triassic, with highest diversity around 20° N. Reconstructed terrestrial LDGs contrast strongly with the generally unimodal gradients of today, potentially reflecting high global temperatures and prevailing Pangaean super-monsoonal climate system during the Permo-Triassic.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC7329043/",
    doi = "10.1098/rspb.2020.1125",
    pmcid = "PMC7329043",
    pmid = "32546099"
}

@article{doi101371journalpone0259369,
    author = "Kulik, Zoe T and Lungmus, Jacqueline K and Angielczyk, Kenneth D and Sidor, Christian A",
    title = "Living fast in the Triassic: New data on life history in Lystrosaurus (Therapsida: Dicynodontia) from northeastern Pangea.",
    year = "2021",
    journal = "PloS one",
    abstract = "Lystrosaurus was one of the few tetrapods to survive the Permo-Triassic mass extinction, the most profound biotic crisis in Earth's history. The wide paleolatitudinal range and high abundance of Lystrosaurus during the Early Triassic provide a unique opportunity to investigate changes in growth dynamics and longevity following the mass extinction, yet most studies have focused only on species that lived in the southern hemisphere. Here, we present the long bone histology from twenty Lystrosaurus skeletal elements spanning a range of sizes that were collected in the Jiucaiyuan Formation of northwestern China. In addition, we compare the average body size of northern and southern Pangean Triassic-aged species and conduct cranial geometric morphometric analyses of southern and northern taxa to begin investigating whether specimens from China are likely to be taxonomically distinct from South African specimens. We demonstrate that Lystrosaurus from China have larger average body sizes than their southern Pangean relatives and that their cranial morphologies are distinctive. The osteohistological examination revealed sustained, rapid osteogenesis punctuated by growth marks in some, but not all, immature individuals from China. We find that the osteohistology of Chinese Lystrosaurus shares a similar growth pattern with South African species that show sustained growth until death. However, bone growth arrests more frequently in the Chinese sample. Nevertheless, none of the long bones sampled here indicate that maximum or asymptotic size was reached, suggesting that the maximum size of Lystrosaurus from the Jiucaiyuan Formation remains unknown.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC8570511/",
    doi = "10.1371/journal.pone.0259369",
    pmcid = "PMC8570511",
    pmid = "34739492"
}

@article{doi101038s42003022041626,
    author = "Qiao, Yu and Liu, Jun and Wolniewicz, Andrzej S and Iijima, Masaya and Shen, Yuefeng and Wintrich, Tanja and Li, Qiang and Sander, P Martin",
    title = "A globally distributed durophagous marine reptile clade supports the rapid recovery of pelagic ecosystems after the Permo-Triassic mass extinction.",
    year = "2022",
    journal = "Communications biology",
    abstract = "Marine ecosystem recovery after the Permo-Triassic mass extinction (PTME) has been extensively studied in the shallow sea, but little is known about the nature of this process in pelagic ecosystems. Omphalosauridae, an enigmatic clade of open-water durophagous marine reptiles, potentially played an important role in the recovery, but their fragmentary fossils and uncertain phylogenetic position have hindered our understanding of their role in the process. Here we report the large basal ichthyosauriform Sclerocormus from the Early Triassic of China that clearly demonstrates an omphalosaurid affinity, allowing for the synonymy of the recently erected Nasorostra with Omphalosauridae. The skull also reveals the anatomy of the unique feeding apparatus of omphalosaurids, likely an adaptation for feeding on hard-shelled pelagic invertebrates, especially ammonoids. Morphofunctional analysis of jaws shows that omphalosaurids occupy the morphospace of marine turtles. Our discovery adds another piece of evidence for an explosive radiation of marine reptiles into the ocean in the Early Triassic and the rapid recovery of pelagic ecosystems after the PTME.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC9663502/",
    doi = "10.1038/s42003-022-04162-6",
    pmcid = "PMC9663502",
    pmid = "36376479"
}

@article{doi101111joa13770,
    author = "Jenkins, Kelsey M and Meyer, Dalton L and Lewis, Patrick J and Choiniere, Jonah N and Bhullar, Bhart-Anjan S",
    title = "Re-description of the early Triassic diapsid Palacrodon from the lower Fremouw formation of Antarctica.",
    year = "2022",
    journal = "Journal of anatomy",
    abstract = "The rapid radiation and dispersal of crown reptiles following the end-Permian mass extinction characterizes the earliest phase of the Mesozoic. Phylogenetically, this early radiation is difficult to interpret, with polytomies near the crown node, long ghost lineages, and enigmatic origins for crown group clades. Better understanding of poorly known taxa from this time can aid in our understanding of this radiation and Permo-Triassic ecology. Here, we describe an Early Triassic specimen of the diapsid Palacrodon from the Fremouw Formation of Antarctica. While Palacrodon is known throughout the Triassic and exhibits a cosmopolitan geographic range, little is known of its evolutionary relationships. We recover Palacrodon outside of crown reptiles (Sauria) but more crownward than Youngina capensis and other late Permian diapsids. Furthermore, Palacrodon possesses anatomical features that add clarity to the evolution of the stapes within the reptilian lineage, as well as incipient adaptations for arboreality and herbivory during the earliest phases of the Permo-Triassic recovery.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC9644968/",
    doi = "10.1111/joa.13770",
    pmcid = "PMC9644968",
    pmid = "36168715"
}

@article{doi101016jcub202304007,
    author = "Kammerer, Christian F and Viglietti, Pia A and Butler, Elize and Botha, Jennifer",
    title = "Rapid turnover of top predators in African terrestrial faunas around the Permian-Triassic mass extinction.",
    year = "2023",
    journal = "Current biology: CB",
    abstract = "Catastrophic ecosystem disruption in the late Permian period resulted in the greatest loss of biodiversity in Earth's history, the Permian-Triassic mass extinction (PTME).1 The dominant terrestrial vertebrates of the Permian (synapsids) suffered major losses at this time, leading to their replacement by reptiles in the Triassic.2 The dominant late Permian predatory synapsids, gorgonopsians, were completely extirpated by the PTME. The largest African gorgonopsians, the Rubidgeinae, have traditionally been assumed to go extinct at the Permo-Triassic boundary (PTB).3,4,5 However, this apparent persistence through the sustained extinction interval characterizing the continental PTME6 is at odds with ecological theory indicating that top predators have high extinction risk.7 Here, we report the youngest known large-bodied gorgonopsians, gigantic specimens from the PTB site of Nooitgedacht 68 in South Africa. These specimens are not rubidgeine, and instead are referable to Inostrancevia, a taxon previously thought to be a Russian endemic.8 Based on comprehensive review of the South African gorgonopsian record, we show that rubidgeines were early victims of ecosystem disruption preceding the PTME and were replaced as top predators by Laurasian immigrant inostranceviines. The reign of this latter group was short-lived, however; by the PTB, gorgonopsians were extinct, and a different group (therocephalians) became the largest synapsid predators, before themselves going extinct. The extinction and replacement of top predators in rapid succession at the clade level underlines the extreme degree of ecosystem instability in the latest Permian and earliest Triassic, a phenomenon that was likely global in extent.",
    url = "https://pubmed.ncbi.nlm.nih.gov/37220743/",
    doi = "10.1016/j.cub.2023.04.007",
    pmid = "37220743"
}

@misc{song2023respiratory,
    author = "Song, Haijun and Wu, Yuyang and Dai, Xu and Corso, Jacopo Dal and Wang, Fengyu and Feng, Yan and Chu, Daoliang and Tian, Li and Song, Huyue and Foster, William J.",
    title = "Respiratory protein-driven selectivity during the Permian–Triassic mass extinction",
    year = "2023",
    publisher = "Zenodo",
    abstract = "<strong>Fossil occurrence data</strong> Fossil data used to calculate diversity variation were obtained from a previously published database of Permian‒Triassic marine fossils (Song et al., 2018; Song et al., 2020). The database contains 52,322 occurrences at the generic level from 1,768 published papers and the Paleobiology Database, spanning the Late Permian Changhsingian to the Late Triassic Rhaetian (Data 1). Our analysis is based on the occurrences of genera, as taphonomy prevents species-level identifications. Within the considered interval, a total of 1,097 genera belong to 13 major clades, including two clades of protozoa (foraminifera and radiolarians), nine clades of invertebrates (corals, sponges, brachiopods, bryozoans, ostracods, cephalopods, gastropods, bivalves, and echinoderms), and two clades of vertebrates (conodonts and fishes). For marine arthropods, we used only ostracod data because ostracods are abundant in the fossil record during the late Permian. Other marine arthropods are very rare in this time interval. For example, only two genera of trilobite, one genus of chelicera, and one genus of decapod are recorded in the Changhsingian bin compared to \&gt; 100 genera of ostracods in the Paleobiology Database. We did not consider background extinction in the Late Permian because many studies have shown that the background extinction rate of marine taxa in the Changhsingian is negligible compared to the mass extinction interval around the Permian‒Triassic boundary (Yin et al., 2007; Shen et al., 2011; Song et al., 2013; Fan et al., 2020). Therefore, the results using the Changhsingian and Induan fossil data reflect a selectivity pattern of the Permian‒Triassic mass extinction rather than background extinction. <strong>Body size data</strong> We used the comprehensive database of Schaal et al. (2016) to assign body size expressed as the maximum length for each species. Using the maximum size for each taxon is a common approach for body size studies, as the effects of juvenile specimens in the database can be avoided (Stanley, 1973; Jablonski, 1997; Lockwood, 2005; Heim et al., 2015; Payne et al., 2016; Schaal et al., 2016). We followed the same methods to compile additional data for taxa not included in this database. A number of recently published databases were used to compile the size data, including references (Romano et al., 2016; Shi et al., 2016; Foster et al., 2018; Chen et al., 2019; Feng et al., 2020; Foster et al., 2020). Other size data were mainly obtained from the published taxonomic literature (see Data 2). Only common taxa from both Changhsingian and Induan are included because these taxa have abundant fossil data to study their size change during the Permian-Triassic interval, i.e., foraminifera, brachiopods, ostracods, gastropods, cephalopods, bivalves, conodonts, and fishes. Other taxa including corals, sponges, radiolarians, bryozoans, and echinoderms are absent/very rare in the Induan bin (see Data 1), and accordingly are not included in this study. The Changhsingian and Induan body size dataset is composed of 1495 species in 635 genera belonging to eight common clades. Other data were obtained from the above fossil occurrence and body size datasets. <strong>References</strong> Chen, J., Song, H., He, W., Tong, J., Wang, F., Wu, S., 2019. Size variation of brachiopods from the Late Permian through the Middle Triassic in South China: Evidence for the Lilliput Effect following the Permian-Triassic extinction. Palaeogeography, Palaeoclimatology, Palaeoecology, 519: 248–257. Fan, J.-x., Shen, S.-z., Erwin, D.H., Sadler, P.M., MacLeod, N., Cheng, Q.-m., Hou, X.-d., Yang, J., Wang, X.-d., Wang, Y., 2020. A high-resolution summary of Cambrian to Early Triassic marine invertebrate biodiversity. Science, 367(6475): 272–277. Feng, Y., Song, H., Bond, D.P.G., 2020. Size variations in foraminifers from the early Permian to the Late Triassic: implications for the Guadalupian–Lopingian and the Permian–Triassic mass extinctions. Paleobiology, 46(4): 511–532. Foster, W., Gliwa, J., Lembke, C., Pugh, A., Hofmann, R., Tietje, M., Varela, S., Foster, L., Korn, D., Aberhan, M., 2020. Evolutionary and ecophenotypic controls on bivalve body size distributions following the end-Permian mass extinction. Global and Planetary Change, 185: 103088. Foster, W., Lehrmann, D., Yu, M., Ji, L., Martindale, R., 2018. Persistent environmental stress delayed the recovery of marine communities in the aftermath of the latest Permian mass extinction. Paleoceanography and Paleoclimatology, 33(4): 338–353. Heim, N.A., Knope, M.L., Schaal, E.K., Wang, S.C., Payne, J.L., 2015. Cope's rule in the evolution of marine animals. Science, 347(6224): 867–870. Jablonski, D., 1997. Body-size evolution in Cretaceous molluscs and the status of Cope's rule. Nature, 385(6613): 250–252. Lockwood, R., 2005. Body size, extinction events, and the early Cenozoic record of veneroid bivalves: a new role for recoveries? Paleobiology, 31(4): 578–590. Payne, J.L., Bush, A.M., Heim, N.A., Knope, M.L., McCauley, D.J., 2016. Ecological selectivity of the emerging mass extinction in the oceans. Science, 353(6305): 1284–1286. Romano, C., Koot, M.B., Kogan, I., Brayard, A., Minikh, A.V., Brinkmann, W., Bucher, H., Kriwet, J., 2016. Permian–Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution. Biological Reviews, 91(1): 106–147. Schaal, E.K., Clapham, M.E., Rego, B.L., Wang, S.C., Payne, J.L., 2016. Comparative size evolution of marine clades from the Late Permian through Middle Triassic. Paleobiology, 42(1): 127–142. Shen, S., Crowley, J.L., Wang, Y., Bowring, S.A., Erwin, D.H., Sadler, P.M., Cao, C., Rothman, D.H., Henderson, C.M., Ramezani, J., Zhang, H., Shen, Y., Wang, X., Wang, W., Mu, L., Li, W., Tang, Y., Liu, X., Liu, L., Zeng, Y., Jiang, Y., Jin, Y., 2011. Calibrating the end-Permian mass extinction. Science, 334(6061): 1367–1372. Shi, G.R., Zhang, Y.-c., Shen, S.-z., He, W.-h., 2016. Nearshore–offshore–basin species diversity and body size variation patterns in Late Permian (Changhsingian) brachiopods. Palaeogeography, Palaeoclimatology, Palaeoecology, 448: 96–107. Song, H., Huang, S., Jia, E., Dai, X., Wignall, P.B., Dunhill, A.M., 2020. Flat latitudinal diversity gradient caused by the Permian–Triassic mass extinction. Proceedings of the National Academy of Sciences, 117(30): 17578–17583. Song, H., Wignall, P.B., Dunhill, A.M., 2018. Decoupled taxonomic and ecological recoveries from the Permo-Triassic extinction. Science Advances, 4(10): eaat5091. Song, H., Wignall, P.B., Tong, J., Yin, H., 2013. Two pulses of extinction during the Permian-Triassic crisis. Nature Geoscience, 6(1): 52–56. Stanley, S.M., 1973. An explanation for Cope's rule. Evolution, 27(1): 1–26. Yin, H., Feng, Q., Lai, X., Baud, A., Tong, J., 2007. The protracted Permo-Triassic crisis and multi-episode extinction around the Permian-Triassic boundary. Global and Planetary Change, 55(1–3): 1–20.",
    url = "https://zenodo.org/record/8079148",
    doi = "10.5281/zenodo.8079148"
}

@article{doi101111joa14201,
    author = "Botha, Jennifer",
    title = "The osteohistology of gorgonopsian therapsids and implications for Permo-Triassic theriodont growth.",
    year = "2025",
    journal = "Journal of anatomy",
    abstract = "During the Late Permian, saber-toothed gorgonopsian therapsids were the dominant terrestrial predators, playing crucial roles as apex predators alongside therocephalian therapsids within Permian terrestrial ecosystems. The entire gorgonopsian clade went extinct during the Permo-Triassic mass extinction, leaving other therapsids to continue into the Triassic. Gorgonopsians have not been well studied, particularly in terms of their growth patterns, with only a few genera having undergone osteohistological analysis. In this study, I present a thorough osteohistological examination of the most extensive collection of gorgonopsian specimens to date, spanning a diverse range of limb bones sourced from various species. The osteohistological analysis of gorgonopsian specimens reveals a trend of rapid growth characterized by a highly vascularized woven-parallel complex. The abundance of growth marks and variable zone widths suggests a growth trajectory that could indicate longer lifespans and slower growth rates when compared to Early Triassic therapsids. The high vascularity, coupled with the observed growth patterns, implies that gorgonopsians experienced rapid growth during favorable conditions. However, the multiple growth marks indicate that they likely had the capacity for longer lifespans and more gradual maturation than their Early Triassic counterparts. Additionally, their ability to reach later ontogenetic stages supports the hypothesis that favorable environmental conditions facilitated larger body sizes. In contrast, Early Triassic therapsids primarily consisted of juveniles or individuals who reached reproductive maturity within a year, likely indicative of harsher conditions that contributed to higher mortality rates at younger ages. The onset of decreased growth rates, usually indicative of reproductive maturity, occurred later in gorgonopsians compared to Early Triassic therapsids and may have contributed to their decline, as the heightened juvenile mortality rates during the PTME would have limited the gorgonopsians' ability to reproduce effectively.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC12079768/",
    doi = "10.1111/joa.14201",
    pmcid = "PMC12079768",
    pmid = "39707522"
}