@misc{walcott1919middle6,
    author = "Walcott, C. D",
    title = "Middle Cambrian Algae. Cambrian Geology and Paleontology, IV",
    year = "1919",
    howpublished = "Smithsonian Miscellaneous Collections, v. 67, p. 217-260",
    note = "talkorigins\_source = {true}; raw\_reference = {Walcott, C. D., 1919, Middle Cambrian Algae. Cambrian Geology and Paleontology, IV: Smithsonian Miscellaneous Collections, v. 67, p. 217-260.}"
}

@article{doi1023072420042,
    author = "Hoskins, J. H. and Fritsch, F. E.",
    title = "The Structure and Reproduction of the Algae.",
    year = "1935",
    journal = "The American Midland Naturalist",
    url = "https://doi.org/10.2307/2420042",
    doi = "10.2307/2420042",
    openalex = "W1602982209"
}

@article{pichova1967microfossils,
    author = "Pichova, N.G.",
    title = "Microfossils of Lower Cambrian and Precambrian deposits in eastern Siberia",
    year = "1967",
    journal = "Review of Palaeobotany and Palynology",
    url = "https://doi.org/10.1016/0034-6667(67)90206-0",
    doi = "10.1016/0034-6667(67)90206-0",
    number = "1-4",
    pages = "31-38",
    volume = "5"
}

@article{doi101128br3521712051971,
    author = "Stanier, Roger Y. and Kunisawa, Riyo and Mandel, M. and Cohen-Bazire, Germaine",
    title = "Purification and properties of unicellular blue-green algae (order Chroococcales)",
    year = "1971",
    journal = "Bacteriological Reviews",
    url = "https://doi.org/10.1128/br.35.2.171-205.1971",
    doi = "10.1128/br.35.2.171-205.1971",
    openalex = "W1857754651",
    references = "doi101002j153721971955tb11120x, doi101007bf00425185, doi101016s0022283661800478, doi10109900221287512199, doi10109900221287512203, doi101111j152988171968tb04667x, doi101128br3344765041969, doi101128jb4244374661941, doi101139m58024, doi101139m60077"
}

@article{doi101016s0015379617307783,
    author = "Jeffrey, S. W. and Humphrey, G. F.",
    title = "New spectrophotometric equations for determining chlorophylls a, b, c1 and c2 in higher plants, algae and natural phytoplankton",
    year = "1975",
    journal = "Biochemie und Physiologie der Pflanzen",
    url = "https://doi.org/10.1016/s0015-3796(17)30778-3",
    doi = "10.1016/s0015-3796(17)30778-3",
    openalex = "W1542162133",
    references = "doi10100797836426496156, doi101007bf00388879, doi1010160005272868901096, doi1010160006300263906176, doi1010160011747165906625, doi1010160304416572902383, doi101016s002192581851320x, doi101021ac60165a029, doi101104pp2411, doi1023071539622"
}

@article{doi101144gsjgs13130289,
    author = "Matthews, Samantha and MISSARZHEVSKY, VLADIMIR V.",
    title = "Small shelly fossils of late Precambrian and early Cambrian age: a review of recent work",
    year = "1975",
    journal = "Journal of the Geological Society",
    abstract = "Stratigraphic sections in the high Precambrianlow Cambrian of Siberia are described. They have yielded the variety of fossils—archaeocyathids, gastropods, hyolithids, hyolithelminthids, poriferids, tommotiids and others—that characterize the Tommotian, Atdabanian and Lenian Stages. Some shelly fossils are found high in the Precambrian (Yudomian). The Tommotian Stage is regarded here as the lowest Cambrian unit. Trilobites first appear at the base of the Atdabanian Stage. A selection of fossils is illustrated and briefly described. Faunas from equivalent levels in Sweden (Tommotian Stage) and England (Nuneaton: Tommotian Stage; Comley: Atdabanian Stage) are cited. Comments are offered on ranges and on distribution (it is already apparent that certain Atdabanian Stage fossils are not restricted to the “provinces” identified for trilobites). The problems of recognizing primary shell-structure, the existence of symmetry-pairings, the manner of coiling of shells and the occurrence of perforations of shells (some seemingly due to boring by predators) are also discussed.",
    url = "https://doi.org/10.1144/gsjgs.131.3.0289",
    doi = "10.1144/gsjgs.131.3.0289",
    openalex = "W2013138167",
    references = "doi1010160012825272900724, doi1010160031018272900508, doi101111j150239311968tb01625x, doi101111j150239311970tb00829x, doi101111j150239311971tb01280x, doi101126science14636521674, doi101144gsljgs1920076010410, doi105962bhltitle38279, openalexw2588295003"
}

@incollection{doi10182618200094189197601,
    author = "Vidal, Gonzalo",
    title = "Late Precambrian microfossils from the Visingsö Beds in southern Sweden",
    year = "1976",
    booktitle = "Fossils and strata",
    abstract = "Acid-resistant organic microfossils are described from outcrops and a boring through the middle and upper units of the Visingsö Beds in southern Sweden. 21 previously described acritarch species have been identified, and five new species are erected. The acritarchs include simple, although characteristically ornamented sphaeromorphs, one polygonomorph species and one acanthomorph species. Their mode of occurrence and possible lithofacial relationships are discussed. The acritarchs from the middle unit of the Visingsö Beds indicate a Late Riphean age. The upper unit contains acritarchs previously known from Vendian and Lower Cambrian strata in the U.S.S.R., China and elsewhere. A Vendian age is suggested for this unit. A glacial origin is suggested for boulder beds in the middle unit of the Visingsö Beds.",
    url = "https://doi.org/10.18261/8200094189-1976-01",
    doi = "10.18261/8200094189-1976-01",
    openalex = "W4385617878",
    references = "doi1010160012825272901316, doi10108011035896709448374, doi101111j1469185x1970tb01644x, doi101126science1473658563, doi101126science148366627, doi101126science16138451005, doi101139e67013, doi10182618200093581197401, openalexw2326083785, openalexw2622880403, pichova1967microfossils"
}

@article{monty1977evolving3,
    author = "Monty, C. L. V",
    title = "Evolving concepts on the nature and the ecological significance of stromatolites - a review, in Fuegel, F., ed., Fossil Algae",
    year = "1977",
    journal = "Berlin, New York, Springer-Verlag, p. 15-35",
    note = "talkorigins\_source = {true}; raw\_reference = {Monty, C. L. V., 1977, Evolving concepts on the nature and the ecological significance of stromatolites - a review, in Fuegel, F., ed., Fossil Algae: Berlin, New York, Springer-Verlag, p. 15-35.}"
}

@misc{shenfil1978algae4,
    author = "Shenfil', V. Y",
    title = "Algae in the Riphean deposits of the Yenesei Ridge [in Russian]",
    year = "1978",
    howpublished = "Doklady Akad. Nauk. SSSR, v. 240, no. 5, p. 1217-1218",
    note = "talkorigins\_source = {true}; raw\_reference = {Shenfil', V. Y., 1978, Algae in the Riphean deposits of the Yenesei Ridge [in Russian]: Doklady Akad. Nauk. SSSR, v. 240, no. 5, p. 1217-1218.}"
}

@article{morris1980shelly,
    author = "Morris, S. Conway and Fritz, W. H.",
    title = "Shelly microfossils near the Precambrian–Cambrian boundary, Mackenzie Mountains, northwestern Canada",
    year = "1980",
    journal = "Nature",
    url = "https://doi.org/10.1038/286381a0",
    doi = "10.1038/286381a0",
    number = "5771",
    openalex = "W2156249302",
    pages = "381-384",
    volume = "286",
    references = "doi1010160012825275901208, doi101017s0094837300004796, doi101070rm1968v023n05abeh001245, doi101111j150239311971tb01864x, doi101144gsjgs13130289, doi1023071483846, doi1023072406301, doi102475ajs2695417"
}

@misc{shenfil1980obruchevella5,
    author = "Shenfil', V. Y",
    title = "Obruchevella in the Riphean deposits of the Yenisei Ridge [in Russian]",
    year = "1980",
    howpublished = "Doklady Akad. Nauk. SSSR, v. 254, no. 4, p. 993-994",
    note = "talkorigins\_source = {true}; raw\_reference = {Shenfil', V. Y., 1980, Obruchevella in the Riphean deposits of the Yenisei Ridge [in Russian]: Doklady Akad. Nauk. SSSR, v. 254, no. 4, p. 993-994.}"
}

@article{doi103133ofr81743,
    author = "Taylor, Michael E. and Mintinc, U Wvemweiit and Palmer, Allison and Robison, Richard and Rowell, Albert and Espizua, Stella and Roberto, Caminos and Toselli, Rossi De and Salfity, J and Toselli, A and Godeas, J and Lunatus, E Nordenskioeldi and Inflata, S and Spinosa, S and Kullingi, S and Fm, Gislbv and 2, / and Sh, Ekre and Ss, Kalmarsund and Grandis, H and Mobergi, H and Yenhao, Lu and Zhaoling, Zhu and Acerolaza, P and Ahlberg, Per and Cook, H and P, En and Kopaska-Merkel, D and Kurtz, V and P, En and Lafuste, J and Cl and Miller and Parrish, J and P, Tn and Pojeta, John and Repetski, J and P, En and Brasier, M and Hewitt, R and Brasier, C and Brasier, M and Hewitt, R and Cobbold, E and Cobbold, E and Pocock, R and Cowie, J and Rushton, A and Stubblefield, C and Fritz, W and Grabau, A and Hupe, Pierre and Landing, E and Nowland, G and Fletcher, T and Matthew, G and Matthews, S and Cowie, J and Matthews, S and Missarzhevsky, V and Patchett, J and Gale, N and Goodwin, R and Humm, M and Poulsen, Christian and Poulsen, V and Rozanov, A and Yu and Rushton, A and Walcott, C and Crevello, P and Schlager, W and Dietz, R and Holden, J and Edgar, N and Saunders, J and Embley, R and Fan, Pow-Foong and Rex and Cook, R and Zemmels, H and Edgar, I M^ and Saunders, N and J and Johns, D and Mutti, E and Resell, J and Deguret, M and Kay, M and Mountjoy, E and Cook, H and Pray, L and Mcdaniel, P and Redfield, A and Ketchum, B and Richards, F and Rees, M and Rowell, A and Schlager, W and Chermak, A",
    title = "Short papers for the Second International Symposium on the Cambrian System, 1981",
    year = "1981",
    journal = "Antarctica A Keystone in a Changing World",
    abstract = "The Cambrian System holds special scientific interest because it contains the primary record of the earliest evolutionary diversification of metazoan life on Earth. Study of the patterns of evolutionary diversification and associated environmental conditions provides our understanding of the original colonization of the Earth's marine ecosystem by complex plant and animal communities. Rocks of Cambrian age contain a significant portion of the world's sedimentary and metallic mineral resources. Increased understanding of Cambrian stratigraphy, depositional environments, and paleogeography improves our ability to discover new deposits which are so necessary to the agricultural and industrial well being of the world's human population. This volume is the proceedings of the technical sessions of the Second International Symposium on the Cambrian System, held August 9-13, 1981, in Golden, Colorado. The first international Cambrian symposium was held in conjunction with the 20th International Geological Congress in Mexico City in 1956. Since 1956, a wealth of research on Cambrian stratigraphy and paleontology has been conducted in all parts of the world. This volume contains a sample of that work in 72 scientific reports authored or coauthored by 95 research scientists. Thirteen countries are represented by the contributors, including the United States of America (37), the Union of Soviet Socialist Republics (16), the People's Republic of China (12), England (6), Australia (5), Sweden (5), Canada (3), France (3), Argentina (2), Estonia (2), West Germany (2), South Korea (1), and Poland (1).",
    url = "https://doi.org/10.3133/ofr81743",
    doi = "10.3133/ofr81743",
    openalex = "W64497491",
    references = "doi1010160012825272900724, doi101017s0094837300003778, doi101017s0094837300005972, doi101017s0094837300006539, doi101017s0094837300006588, doi101146annureven10010165000525, doi1023071441916, doi1023072412825, doi1023072806339, openalexw1488584644"
}

@misc{kolosov1982upper1,
    author = "Kolosov, P. N",
    title = "Upper Precambrian Paleoalgological Remains of the Siberian Platform [in Russian]",
    year = "1982",
    howpublished = "Moscow, Nauks, 96 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Kolosov, P. N., 1982, Upper Precambrian Paleoalgological Remains of the Siberian Platform [in Russian]: Moscow, Nauks, 96 p.}"
}

@phdthesis{yankauskas1982upper8,
    author = "Yankauskas, T. V",
    title = "Upper Precambrian and Cambrian plant microfossils of the European USSR and their stratigraphic significance [in Russian] [Ph.D. dissert.]",
    year = "1982",
    publisher = "University of Moscow, Moscow, 52 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Yankauskas, T. V., 1982, Upper Precambrian and Cambrian plant microfossils of the European USSR and their stratigraphic significance [in Russian] [Ph.D. dissert.]: University of Moscow, Moscow, 52 p.}"
}

@misc{makarikhin1983phytolites2,
    author = "Makarikhin, V. V. and Kononova, G",
    title = "Phytolites of the Karelian Lower Proterozoic [in Russian]",
    year = "1983",
    howpublished = "Leningrad, Nauka, 180 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Makarikhin, V. V., and Kononova, G., 1983, Phytolites of the Karelian Lower Proterozoic [in Russian]: Leningrad, Nauka, 180 p.}"
}

@incollection{walter1983archean7,
    author = "Walter, M. R",
    editor = "Schopf, J. W.",
    title = "Archean Stromatolites: Evidence of the Earth's Earliest Benthos",
    year = "1983",
    booktitle = "Earth's Earliest Biosphere",
    publisher = "Its Origin and Evolution: Princeton, Princeton University Press, p. 187-213",
    note = "talkorigins\_source = {true}; raw\_reference = {Walter, M. R., 1983, Archean Stromatolites: Evidence of the Earth's Earliest Benthos, in Schopf, J. W., ed., Earth's Earliest Biosphere: Its Origin and Evolution: Princeton, Princeton University Press, p. 187-213.}"
}

@article{doi101017s0016756800028296,
    author = "Brasier, Martin D.",
    title = "Microfossils and small shelly fossils from the Lower Cambrian Hyolithes Limestone at Nuneaton, English Midlands",
    year = "1984",
    journal = "Geological Magazine",
    abstract = "Abstract The Lower Cambrian sequence at Nuneaton is outlined, paying particular attention to the 2 m thick Home Farm Member (including the Hyolithes Limestone) and its faunal succession at the type locality, Woodlands Quarry, Hartshill. There follows the first modern description and illustration of microfossils and small shelly fossils from this member. Of thirty-two species covered here, twenty are described and illustrated from Nuneaton for the first time and eight of these are new records. The varied fauna includes phosphatic and calcareous microproblematica (especially Coleoloides typicalis), protoconodonts, agglutinated foraminifera, cap-shaped molluscs, primitive bivalves, hyoliths, inarticulate brachiopods and sponges. The fauna has affinity with fossils in the top Tommotian to lower Atdabanian rocks from Siberia and China, from the Baltic area and the belt from southeast Newfoundland to Massachusetts.",
    url = "https://doi.org/10.1017/s0016756800028296",
    doi = "10.1017/s0016756800028296",
    openalex = "W1970229985",
    references = "doi1010160012825280900641, doi101017cbo9781139104067002, doi10108003115517608619064, doi101127zdgg1111959434, doi101139e83050, doi101144gsjgs13130289, doi101144gsljgs1920076010410, doi1023072992311, doi105962bhltitle38279, doi105962bhltitle82327, openalexw2588295003"
}

@article{brasier1987microfossils,
    author = "Brasier, M. D. and Singh, P.",
    title = "Microfossils and Precambrian–Cambrian boundary stratigraphy at Maldeota, Lesser Himalaya",
    year = "1987",
    journal = "Geological Magazine",
    abstract = "An assemblage of problematical microfossils of Precambrian–Cambrian boundary age is redescribed from the Chert–Phosphorite Member, at the base of the Lower Tal Formation of Maldeota in the Lesser Himalaya of India. This assemblage has previously been ascribed to various ages, from Precambrian to Cretaceous, but is held by us to contain: Maldeotaia bandalica, Protohertzina anabarica group, trumpet-shaped elements, acicular elements A \& B,? Conotheca sp., Ovalitheca cf. multicostata, allathecid sp. A, Barbitositheca ansata, Hexangulaconularia cf. formosa, Coleoloides aff. typicalis, Hyolithellus aff. insolitus, H. cf. isiticus, H. vladimirovae, Spirellus shankari and Olivooides multisulcatus. These compare closely with assemblages found above the base of the first, Anabarites trisulcatus–Protohertzina anabarica Zone in China and in the second, Pseudorthotheca costata Zone of southern Kazakhstan. The stratigraphic setting of the Krol–Tal succession is reviewed and several similarities are noted between the Precambrian–Cambrian boundary successions of Lesser Himalaya in India and of Yunnan and Sichuan in Southwest China, indicating that correlation between them is possible at several levels.",
    url = "https://doi.org/10.1017/s0016756800016666",
    doi = "10.1017/s0016756800016666",
    number = "4",
    openalex = "W2155030845",
    pages = "323-345",
    volume = "124",
    references = "doi1010160012825272900724, doi101017s0016756800028296, doi101038320258a0, doi101111j150239311977tb00628x, doi101127zdgg1111959434, doi101139e83050, doi101144gsjgs13130289, doi10182618200067378198301, doi1018814epiiugs1985v8i2003, morris1980shelly, openalexw2207565996"
}

@article{doi101017s0016756800015922,
    author = "Crimes, T. P.",
    title = "Trace fossils and correlation of late Precambrian and early Cambrian strata",
    year = "1987",
    journal = "Geological Magazine",
    abstract = "Abstract Trace fossils are abundant and diverse in many clastic sequences spanning the Precambrian-Cambrian boundary and may prove to be the most useful palaeontological method for global correlation in this stratigraphic interval. The ichnofaunas of the latest Precambrian (Vendian) rocks include some forms whose range does not extend into the Cambrian (e.g. Bilinichnus, Intrites, Palaeopascichnus, Vendichnus, Vimenites) and others which continue throughout most or all of the Phanerozoic (e.g. Arenicolites, Aulichnites, Cochlichnus, Didymaulichnus, Gordia, Neonereites, Planolites, Skolithos). At least 50 ichnogenera make their first appearance below the lowest trilobites in sections with broad geographic spread. A few of these appear to have a short time range, extending to about the incoming of the trilobites (e.g. Astropolichnus, Didymaulichnus miettensis, Plagiogmus, Taphrhelminthopsis circularis), but the majority continue through most or all of the Phanerozoic. For correlation of Precambrian-Cambrian boundary sequences it is therefore possible to use both the occurrence of those ichnogenera with a short time range and the incoming of those with an extended range. Three stratigraphical zones can be recognized with respect to the incoming of trace fossils. Zone I is of Upper Vendian age and includes Arenicolites, Bilinichnus, Cochlichnus, Didymaulichnus, Gordia, Harlaniella, Intrites, Nenoxites, Neonereites, Palaeopascichnus, Skolithos, Vendichnus and Vimenites. In Zone II, of Lower Tommotian age, the earliest examples of Bergaueria, Phycodes, Teichichnus and Treptichnus are encountered. Many trace fossils appear in Zone III, which extends from Upper Tommotian to Lower Atdabanian, but the most important are: Astropolichnus, Cruziana, Diplichnites, Diplocraterion, Dimorphichnus, Plagiogmus, Rusophycus and Taphrhelminthopsis circularis. This vertical zonation of trace fossils allows an attempt at world-wide correlation, from which the most significant conclusions are that the Vendian/Tommotian boundary can probably be placed: (i) near the middle of the McNaughton Formation in the Rocky Mountains, Canada; (ii) at the base of the Deep Spring Formation or in the underlying Reed Dolomite in the White Inyo Mountains, California, U.S.A.; (iii) low in the Chapel Island Formation in the Burin Peninsula, Newfoundland, Canada; (iv) at or close to the base of the Candana Quartzite in North Spain; (v) at or below the base of the Breivik Member in Finnmark, Norway; and (vi) near or below the base of the Zhongyicun Member at Meischucun, China. The sections in the Burin Peninsula, Newfoundland and Meischucun, China are favoured candidates for the global stratotype for the Precambrian-Cambrian boundary. In the Burin Peninsula, the trace fossils suggest that the Tommotian/Atdabanian boundary may be within or at the base of the Random Formation, thereby implying that the Tommotian may include a thickness of 500 m of sediment comprising at least most of the Chapel Island Formation. At Meishucun, the ichnofaunal evidence implies that the Tommotian/Atdabanian boundary is probably no higher than the top of the Zhongyicun Member. The thickness of the Tommotian is therefore possibly only about 20 m here, implying a very condensed sequence, a conclusion consistent with an abundance of phosphorites. Two stratotype reference points for the Precambrian-Cambrian boundary have been suggested in this section. The lower point (0.8 m above the base of the Xiawaitoushan Member) may be near the Vendian/Tommotian boundary or younger, while the higher point (base of Unit 7 of the Zhongyicun Member) is probably Upper Tommotian or even Lower Atdabanian. The higher point would place the boundary above the world-wide dramatic increase in trace fossil abundance and diversity but probably before the first trilobites. This would almost certainly have advantages for correlation. The inference that the Meishucun section is younger than most Chinese work suggests should not therefore, by itself, prejudice its adoption as global stratotype. In general, where comparative data are available, the trace fossil correlations agree well with pre-existing proposals based on small shelly fossils. The degree of resolution of the two methods would appear at present to be similar but trace fossils, being found mainly in clastic facies, may benefit from more frequent occurrence.",
    url = "https://doi.org/10.1017/s0016756800015922",
    doi = "10.1017/s0016756800015922",
    openalex = "W1969566004",
    references = "doi101139e83050"
}

@article{doi101017s0022336000029292,
    author = "Knoll, Andrew H. and Swett, Keene",
    title = "Micropaleontology across the Precambrian—Cambrian boundary in Spitsbergen",
    year = "1987",
    journal = "Journal of Paleontology",
    abstract = "Paleobiological studies of early metazoan evolution are critically dependent on the accurate stratigraphic subdivision and correlation of uppermost Proterozoic and Lower Cambrian sequences. Planktonic microfossils evolved rapidly during this period and are widely distributed and abundant in Vendian and Lower Cambrian rocks; therefore, they provide what is potentially one of the best means of correlating successions of this age. In Ny Friesland, Spitsbergen, tillite-bearing detrital rocks of the uppermost Proterozoic Polarisbreen Group are overlain without apparent unconformity by the Tokammane Formation, a tripartite lithologic sequence consisting of quartzarenites (Blårevbreen Member) overlain by dark shales with subordinate sandstone (Topiggane Member) and dolomites (Ditlovtoppen Member). Salterella, hyoliths, and other invertebrate remains occur in the upper part of the Tokammane succession; trace fossils are found in the Tokammane quartzarenites and shales, as well as in the uppermost few meters of the Polarisbreen sequence. Planktonic microfossils occur throughout the succession. They indicate that the Polarisbreen Group is Vendian in age and that a hiatus corresponding in time to the latest Vendian and (perhaps) earliest Cambrian coincides with the Polarisbreen/Tokammane boundary. Lower Topiggane shale samples contain acritarchs comparable to those found in the sub- Holmia Lontova Beds of Eastern Europe. Upper Topiggane samples contain diverse acritarch assemblages that indicate a late Holmia or Protolenus age, suggesting the presence of a second hiatus within the Tokammane Formation. Planktonic microfossils allow biostratigraphic correlation with other sequences both within (East Greenland) and between (East European Platform) paleocontinents. Like those from other areas, diversity trends exhibited by late Proterozoic and Early Cambrian acritarchs from Spitsbergen indicate a major Vendian episode of extinction followed by Early Cambrian rediversification of planktonic microfossils.",
    url = "https://doi.org/10.1017/s0022336000029292",
    doi = "10.1017/s0022336000029292",
    openalex = "W1565165024",
    references = "doi1010160301926881900656"
}

@article{doi101139e87124,
    author = "Narbonne, Guy M. and Myrow, Paul M. and Landing, Ed and Anderson, Michael M.",
    title = "A candidate stratotype for the Precambrian–Cambrian boundary, Fortune Head, Burin Peninsula, southeastern Newfoundland",
    year = "1987",
    journal = "Canadian Journal of Earth Sciences",
    abstract = "The Burin Peninsula exhibits an exceptionally thick and essentially continuous succession of marine strata through the Precambrian–Cambrian transition. Fossils are abundant and include trace fossils, small shelly fossils, vendotaenid algae, soft-bodied megafossils, and microfossils. The Burin Peninsula is readily accessible and has long been considered a potential area for a Precambrian–Cambrian boundary stratotype.A continuous section through the upper part of member 1 and all of member 2 of the Chapel Island Formation is exposed at Fortune Head, and this section is herein proposed as a global stratotype for the Precambrian–Cambrian boundary. The boundary horizon is located 2.4 m above the base of member 2 of the Chapel Island Formation. This horizon marks the base of the basal Cambrian Phycodes pedum (ichnofossil) Zone and immediately overlies the top of the Late Precambrian Harlaniella podolica (ichnofossil) Zone. Shelly fossils (sabelliditids) first appear a few metres below the proposed boundary. Soft-bodied megafossils, carbonaceous impressions of vendotaenid algae, and organic-walled microfossils occur both below and above this boundary and enhance global correlation with this section.Fossils of the Rusophycus avalonensis (ichnofossil) Zone first appear midway through member 2 (approximately 135 m above the proposed boundary) and occur commonly throughout the upper part of the Chapel Island Formation and the overlying Random Formation. Calcareous small shelly fossils (?Circotheca sp.) appear near the top of member 2 (approximately 400 m above the proposed boundary), and a more diverse Aldanella attleborensis small shelly fossil assemblage characterizes the uppermost strata of member 3 and all of member 4 of the Chapel Island Formation (approximately 550–650 m above the proposed boundary). The lowest trilobites, representatives of the Callavia broeggeri Zone, first appear more than 1000 m above the proposed Precambrian–Cambrian boundary.",
    url = "https://doi.org/10.1139/e87-124",
    doi = "10.1139/e87-124",
    openalex = "W2152030224",
    references = "cloud1982the, doi101017s0016756800015922, doi101111j150239311969tb01258x, doi101111j150239311970tb01265x, doi101126science2174562783, doi101130mem158p33, doi101139e78010, doi1023072412725, doi102475ajs2748833, doi105281zenodo16572510, hiscott1982tidal, openalexw2611846784, openalexw3116078484"
}

@misc{yankauskas19875th9,
    author = "Yankauskas, T. V. and Mikhailova, N. S. and German, T. N",
    title = "5th All Union colloquium on microfossils of the USSR Precambrian [in Russian]",
    year = "1987",
    howpublished = "Izvestia Akadamie Nauk SSSR Series Geol., v. 9, p. 137-139",
    note = "talkorigins\_source = {true}; raw\_reference = {Yankauskas, T. V., Mikhailova, N. S., and German, T. N., 1987, 5th All Union colloquium on microfossils of the USSR Precambrian [in Russian]: Izvestia Akadamie Nauk SSSR Series Geol., v. 9, p. 137-139.}"
}

@incollection{doi10182618200374742199101,
    author = "Moczydłowska, Małgorzata",
    title = "Acritarch biostratigraphy of the Lower Cambrian and the Precambrian-Cambrian boundary in southeastern Poland",
    year = "1991",
    booktitle = "Fossils and strata",
    abstract = "Acritarchs in the sedimentologically continuous, shallow-marine, Upper Vendian - Lower Cambrian subsurface sequence of the Lublin Slope, East European Platform (EEP), Poland are abundant and well-preserved. Forty-five form-species were recovered, and their taxonomic status is revised. Three new form-genera are erected. Asteridium n.gen. and Heliosphaeridium n. gen. include species with solid and hollow processes, respectively, previously referred to Micrhystridium Deflandre. Globosphaeridium n.gen. includes acritarchs with solid processes formerly attributed to Baltisphaeridium Eisenack. The genus Skiagia is emended. Microfossil preservation yields information on the thermal history of the Lublin basin. The acritarch succession in the Lublin Slope forms the basis for a new Lower Cambrian zonation, in ascending order the Asteridium tornaturn - Comasphaeridium velvetum, Skiagia ornata - Fimbriaglomerella membranacea, Heliosphaeridium dissimilare - Skiagia ciliosa, and Volkovia dentifera - Liepaina plana Assemblage-zones. A significant radiation at the upper part of the Włodawa Formation and within the Mazowsze Formation involves taxa of the Asteridiumtornatum - Comasphaeridium velvetum assemblage taken to mark the Pre cambrian-Cambrian boundary. The Kaplonosy IG-1 drillcore is proposed as reference section for the boundary. The Upper Vendian - Lower Cambrian biostratigraphy in Poland is revised. The Sabellidites-Vendotaenia Interval-zone is proposed, the range of the Platysolenites antiquissimus Zone is revised, and the Holmia kjerulfi Assemblage-zone is recognized. The Protolenus zone remains as an informal zone. Parts of the investigated sequence are correlated with the Schmidtiellus mickwitzi Zone elsewhere. The early Cambrian Mobergella Zone and the Klimontovian Stage are rejected. The Precambrian-Cambrian boundary is discussed in light of acritarch evidence from sequences in the East European, Baltoscandian, Siberian, South China and Avalon Platforms. The acritarch zone contemporaneous with the earliest trilobite zone in the Baltoscandian Platform and the EEP embraces part of the Tommotian and Meishucunian strata in Siberia and China. Units underlying the Tommotian in Siberia may be Cambrian. Lower Cambrian rocks of the EEP, the Baltoscandian Platform, and the Scandinavian Caledonides, are correlated on the basis of acritarchs.",
    url = "https://doi.org/10.18261/8200374742-1991-01",
    doi = "10.18261/8200374742-1991-01",
    openalex = "W4385659530",
    references = "doi1010079783642964466, doi1010160012825272901316, doi1010160012825273900925, doi1010160016703784900899, doi1010160301926887900015, doi1010160301926887900441, doi1010160377839888900023, doi101017s0022336000036465, doi101017s0263593300010051, doi101038321832a0, doi101038333313a0, doi101038scientificamerican0779122, doi101073pnas492158, doi10108011035898209455245, doi101130001676061972831299peboto20co2, doi101139e83050, doi10182618200093301197301, doi1018814epiiugs1985v8i2003, doi1023071484559, doi1023071485622, doi1034194bullgguv1346676, nelson1978late, openalexw2026796374, openalexw2603635224, openalexw2753647789, openalexw353142951, schidlowski1988a, tappan1970geobiologic, vidal1985earths"
}

@book{openalexw1574810993,
    author = "Mann, David G. and Jahns, H. M.",
    title = "Algae: An Introduction to Phycology",
    year = "1996",
    booktitle = "Data Archiving and Networked Services (DANS)",
    abstract = "Algae are ubiquitous; a multitude of species ranging from microscopic unicells to gigantic kelps inhabit the world's oceans, freshwater bodies, soils, rocks, and trees, and are responsible for most of the global production of organic matter by photosynthesis. They thus play a fundamental role in the world's ecosystems and a reliable and modern introduction to their kaleidoscopic diversity, systematics, and phylogeny is indispensable. In this textbook, the main groups of algae (divisions or phyla) are considered in turn. Each chapter begins with a summary of the principal characteristics of the group and interesting aspects of ecology and evolution. The final chapter is a synthesis, in which the phylogeny of the algae is discussed in relation to the evolution of other living organisms, primarily on the basis of evidence from recent molecular studies. This book is the completely revised and updated edition of a highly acclaimed German work, which was heralded for its clarity as well as its breadth and depth of information. This new edition takes into account recent reevaluations in algal systematics and phylogeny provided by the powerful techniques of molecular genetics and electron microscopy, as well as more traditional life history studies. The book will be appropriate as an undergraduate text and as a reference for professionals in the field.",
    url = "https://openalex.org/W1574810993",
    openalex = "W1574810993"
}

@article{crossref1998interpreting,
    title = "Interpreting Late Precambrian Microfossils",
    year = "1998",
    journal = "Science",
    url = "https://doi.org/10.1126/science.282.5395.1781r",
    doi = "10.1126/science.282.5395.1781r",
    number = "5395",
    pages = "1781r-1781",
    volume = "282"
}

@article{tiwari1999organicwalled,
    author = "Tiwari, Meera",
    title = "Organic-walled microfossils from the Chert–phosphorite Member, Tal Formation, Precambrian–Cambrian Boundary, India",
    year = "1999",
    journal = "Precambrian Research",
    url = "https://doi.org/10.1016/s0301-9268(99)00023-6",
    doi = "10.1016/s0301-9268(99)00023-6",
    number = "1-2",
    openalex = "W2061127293",
    pages = "99-113",
    volume = "97",
    references = "doi1010079781489924278, doi1010160012825280900641, doi101017s0022336000023283, doi101017s0022336000030663, doi101073pnas492158, doi10108011035898209455245, doi101126science2795352879, doi1011300091761319940220179pcbgsr23co2, doi101139e87124, doi101826182003741571989"
}

@article{doi101016s0043135403002938,
    author = "Davis, Thomas A. and Volesky, Bohumil and Mucci, Alfonso",
    title = "A review of the biochemistry of heavy metal biosorption by brown algae",
    year = "2003",
    journal = "Water Research",
    url = "https://doi.org/10.1016/s0043-1354(03)00293-8",
    doi = "10.1016/s0043-1354(03)00293-8",
    openalex = "W2086492725",
    references = "doi1010079789400958067, doi1010160008621583880537, doi101016s0008621500840513, doi101016s0065237707x32009, doi101016s0167779998012189, doi101021bp00033a001, doi101515zpch19075723, doi1023072484419, openalexw2109966672, openalexw2785226900"
}

@article{doi1011300091761320030310431eocana20co2,
    author = "Amthor, Joachim E. and Grotzinger, J. P. and Schröder, Stefan and Bowring, Samuel A. and Ramezani, Jahandar and Martin, Mark W. and Matter, Albert",
    title = "Extinction of Cloudina and Namacalathus at the Precambrian-Cambrian boundary in Oman",
    year = "2003",
    journal = "Geology",
    abstract = "Biostratigraphic, carbon isotope, and U-Pb zircon geochronological data from the Ara Group of Oman indicate an abrupt last appearance of Cloudina and Namacalathus coincident with a large-magnitude, but short-lived negative excursion in the carbon isotope composition of seawater that is globally coincident with the Precambrian-Cambrian boundary. U-Pb zircon age data from an intercalated ash bed directly define this negative excursion to be at 542.0 ± 0.3 Ma, consistent with previous age constraints from Siberia and Namibia. Combined with the global biostratigraphic record, these new data strengthen hypotheses invoking mass extinction within terminal Proterozoic ecosystems at or near the Precambrian-Cambrian boundary.",
    url = "https://doi.org/10.1130/0091-7613(2003)031<0431:eocana>2.0.co;2",
    doi = "10.1130/0091-7613(2003)031<0431:eocana>2.0.co;2",
    openalex = "W2075619059",
    references = "doi101016s0016703798000593, doi101017s001675680100509x, doi101073pnas092150999, doi101126science11539488, doi101126science2705236598, doi101126science28454232129, doi10113000917613200028143ctfftt20co2, doi1011300091761320010290995oaatpc20co2, doi1016660094837320000260334cmitsr20co2, doi102110jsr681223"
}

@article{doi101111j14754983200500484x,
    author = "Yao, Jinxian and Xiao, Shuhai and Yin, Leiming and Li, Guoxiang and Yuan, Xunlai",
    title = "BASAL CAMBRIAN MICROFOSSILS FROM THE YURTUS AND XISHANBLAQ FORMATIONS (TARIM, NORTH-WEST CHINA): SYSTEMATIC REVISION AND BIOSTRATIGRAPHIC CORRELATION OF MICRHYSTRIDIUM-LIKE ACRITARCHS",
    year = "2005",
    journal = "Palaeontology",
    abstract = "Abstract: Micrhystridium-like acritarchs are widely distributed in basal Cambrian cherts and phosphorites in South China. This paper describes similar acritarchs from the basal Cambrian Yurtus and Xishanblaq formations in Tarim, north-west China. The taxonomy of these acritarchs is revised. The basal Cambrian acritarch assemblage in Tarim and South China is characterized by three genera: Asteridium Moczydłowska, Heliosphaeridium Moczydłowska and Comasphaeridium Staplin, Jansonius and Pocock. This assemblage is named the Asteridium-Heliosphaeridium-Comasphaeridium (AHC) acritarch assemblage. In both South China and Tarim, the AHC acritarch assemblage is associated with the tubular microfossil Megathrix longus Yin L. and the small shelly fossil Kaiyangites novilis Qian and Yin G. This assemblage also occurs in the Lower Tal Formation in the Lesser Himalaya. Correlation with small shelly fossil (SSF) assemblages indicates that the AHC assemblage is restricted to the Meishucunian Stage, and possibly to the lower Meishucunian (Anabarites trisulcatus-Protohertzina anabarica and Siphogonuchites triangularis-Paragloborilus subglobosus SSF assemblages). The AHC assemblage is broadly similar to the Asteridium tornatum-Comasphaeridium velvetum (acritarch) Zone in the East European Platform, which is considered to be Nemakit-Daldynian (and possibly Tommotian) in age.",
    url = "https://doi.org/10.1111/j.1475-4983.2005.00484.x",
    doi = "10.1111/j.1475-4983.2005.00484.x",
    openalex = "W1693703638",
    references = "doi101006dbio20020714, doi101016jpalaeo200202001, doi101016jprecamres200310013, doi101017s009483730001681x, doi101017s0263593300010051, doi101073pnas250491697, doi101098rstb19950029, doi101111j150239311994tb01558x, doi101826182003741571989, doi1023071485800, openalexw2326083785, tiwari1999organicwalled"
}

@article{doi101016jbiotechadv200611002,
    author = "Becker, E. W.",
    title = "Micro-algae as a source of protein",
    year = "2006",
    journal = "Biotechnology Advances",
    url = "https://doi.org/10.1016/j.biotechadv.2006.11.002",
    doi = "10.1016/j.biotechadv.2006.11.002",
    openalex = "W2162336404",
    references = "doi1010029780470995280, doi1010029780470995280ch18, doi101002food19740180314, doi1010160022098194900957, doi101111j15298817200440502x, doi10432497804290362794, doi105860choice320920, openalexw1889712035"
}

@article{doi101016jbiortech200701046,
    author = "Ugwu, Charles U. and Aoyagi, Hideki and Uchiyama, Hiroo",
    title = "Photobioreactors for mass cultivation of algae",
    year = "2007",
    journal = "Bioresource Technology",
    url = "https://doi.org/10.1016/j.biortech.2007.01.046",
    doi = "10.1016/j.biortech.2007.01.046",
    openalex = "W2034993500",
    references = "doi1010029780470995280, doi1010160734975093900036, doi101016s0065216408701278, doi101016s0167779900014335, doi101016s0168165601003534, doi101016s0168165699000784, doi101016s0168165699000838, doi101023a1008106304417, doi101023a1008159127672, openalexw1575620432"
}

@article{doi101007s1064600802140,
    author = "Navarro, Enrique and Baun, Anders and Behra, Renata and Hartmann, Nanna B. and Filser, Juliane and Miao, Ai‐Jun and Quigg, Antonietta and Santschi, Peter H. and Sigg, Laura",
    title = "Environmental behavior and ecotoxicity of engineered nanoparticles to algae, plants, and fungi",
    year = "2008",
    journal = "Ecotoxicology",
    url = "https://doi.org/10.1007/s10646-008-0214-0",
    doi = "10.1007/s10646-008-0214-0",
    openalex = "W2042342613",
    references = "doi101016jjcis200402012, doi101016jnano200612001, doi101088095744841610059, doi101126science1114397, doi101128aem0221806, doi101128cmr121147, doi101146annurevarplant491249, doi101289ehp7339, openalexw1965399445, openalexw3214267983"
}

@article{doi10166607147r1,
    author = "Dong, Lin and Xiao, Shuhai and Shen, Bing and Zhou, Chuanming and Li, Guoxiang and Yao, Jinxian",
    title = "Basal Cambrian microfossils from the Yangtze Gorges area (South China) and the Aksu area (Tarim block, northwestern China)",
    year = "2008",
    journal = "Journal of Paleontology",
    abstract = "The basal Cambrian marks the beginning of an important chapter in the history of life. However, most paleontological work on the basal Cambrian has been focused on skeletal animal fossils, and our knowledge about the primary producers—cyanobacteria and eukaryotic phytoplankton (e.g., acritarchs)—is limited. In this research, we have investigated basal Cambrian acritarchs, coccoidal microfossils, and cyanobacteria preserved in phosphorites and cherts of the Yanjiahe Formation in the Yangtze Gorges area (South China) and the Yurtus Formation in the Aksu area (Tarim Block, northwestern China). Our study confirms the occurrence in these two formations of small acanthomorphic acritarchs characteristic of the basal Cambrian Asteridium–Comasphaeridium–Heliosphaeridium (ACH) assemblage. These acritarchs include abundant Heliosphaeridium ampliatimi (Wang, 1985) Yao et al., 2005, common Yurtusia uniformis n. gen. and n. sp., and rare Comasphaeridium annulare (Wang, 1985) Yao et al., 2005. In addition, these basal Cambrian successions also contain the clustered coccoidal microfossil Archaeophycus yunnanensis (Song in Luo et al., 1982) n. comb., several filamentous cyanobacteria [Cyanonema majus n. sp., Oscillatoriopsis longa Timofeev and Hermann, 1979, and Siphonophycus robustum (Schopf, 1968) Knoll et al., 1991], and the tabulate tubular microfossil Megathrix longus L. Yin, 1987a, n. emend. Some of these taxa (e.g., H. ampliatum, C. annulare, and M. longus) have a wide geographic distribution but occur exclusively in basal Cambrian successions, supporting their biostratigraphic importance. Comparison between the stratigraphic occurrences of microfossils reported here and skeletal animal fossils published by others suggests that animals and phytoplankton radiated in tandem during the Cambrian explosion.",
    url = "https://doi.org/10.1666/07-147r.1",
    doi = "10.1666/07-147r.1",
    openalex = "W1902182613",
    references = "doi101016jpalaeo200703046, doi101017s0094837300003778, doi101029eo082i024p0026802, doi101073pnas0503660102, doi101098rstb20061843, doi101111j150239311994tb01558x, doi101146annurevearth33031504103001, doi101146annurevearth33092203122519, doi1054991jop1973934, doi105860choice304422, lo1980microbial, openalexw2326083785, tiwari1999organicwalled"
}

@article{doi101016jenconman201006055,
    author = "Demirbaş, Ayhan and Demirbas, M. Fatih",
    title = "Importance of algae oil as a source of biodiesel",
    year = "2010",
    journal = "Energy Conversion and Management",
    url = "https://doi.org/10.1016/j.enconman.2010.06.055",
    doi = "10.1016/j.enconman.2010.06.055",
    openalex = "W2084887599",
    references = "doi101007s002530100702, doi1010160022098189900294, doi101016jbiotechadv200702001, doi101016jenconman200802020, doi101016jenpol200704003, doi101016jjbiotec200605002, doi101016jtibtech200712002, doi101111j1365313x200803492x, doi105860choice320920, doi105860choice371896"
}

@article{doi101098rspb20131613,
    author = "Caron, Jean‐Bernard and Smith, Martin R. and Harvey, Thomas H. P.",
    title = "Beyond the Burgess Shale: Cambrian microfossils track the rise and fall of hallucigeniid lobopodians",
    year = "2013",
    journal = "Proceedings of the Royal Society B Biological Sciences",
    abstract = "Burgess Shale-type deposits are renowned for their exquisite preservation of soft-bodied organisms, representing a range of animal body plans that evolved during the Cambrian 'explosion'. However, the rarity of these fossil deposits makes it difficult to reconstruct the broader-scale distributions of their constituent organisms. By contrast, microscopic skeletal elements represent an extensive chronicle of early animal evolution--but are difficult to interpret in the absence of corresponding whole-body fossils. Here, we provide new observations on the dorsal spines of the Cambrian lobopodian (panarthropod) worm Hallucigenia sparsa from the Burgess Shale (Cambrian Series 3, Stage 5). These exhibit a distinctive scaly microstructure and layered (cone-in-cone) construction that together identify a hitherto enigmatic suite of carbonaceous and phosphatic Cambrian microfossils--including material attributed to Mongolitubulus, Rushtonites and Rhombocorniculum--as spines of Hallucigenia-type lobopodians. Hallucigeniids are thus revealed as an important and widespread component of disparate Cambrian communities from late in the Terreneuvian (Cambrian Stage 2) through the 'middle' Cambrian (Series 3); their apparent decline in the latest Cambrian may be partly taphonomic. The cone-in-cone construction of hallucigeniid sclerites is shared with the sclerotized cuticular structures (jaws and claws) in modern onychophorans. More generally, our results emphasize the reciprocal importance and complementary roles of Burgess Shale-type fossils and isolated microfossils in documenting early animal evolution.",
    url = "https://doi.org/10.1098/rspb.2013.1613",
    doi = "10.1098/rspb.2013.1613",
    openalex = "W2092521986",
    references = "doi1011111475498300289, doi101111let12026, doi103140bullgeosci1280, doi104202app20120004"
}

@article{doi101073pnas1719962115,
    author = "Daley, Allison C. and Antcliffe, Jonathan B. and Drage, Harriet B. and Pates, Stephen",
    title = "Early fossil record of Euarthropoda and the Cambrian Explosion",
    year = "2018",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Euarthropoda is one of the best-preserved fossil animal groups and has been the most diverse animal phylum for over 500 million years. Fossil Konservat-Lagerstätten, such as Burgess Shale-type deposits (BSTs), show the evolution of the euarthropod stem lineage during the Cambrian from 518 million years ago (Ma). The stem lineage includes nonbiomineralized groups, such as Radiodonta (e.g., Anomalocaris) that provide insight into the step-by-step construction of euarthropod morphology, including the exoskeleton, biramous limbs, segmentation, and cephalic structures. Trilobites are crown group euarthropods that appear in the fossil record at 521 Ma, before the stem lineage fossils, implying a ghost lineage that needs to be constrained. These constraints come from the trace fossil record, which show the first evidence for total group Euarthropoda (e.g., Cruziana, Rusophycus) at around 537 Ma. A deep Precambrian root to the euarthropod evolutionary lineage is disproven by a comparison of Ediacaran and Cambrian lagerstätten. BSTs from the latest Ediacaran Period (e.g., Miaohe biota, 550 Ma) are abundantly fossiliferous with algae but completely lack animals, which are also missing from other Ediacaran windows, such as phosphate deposits (e.g., Doushantuo, 560 Ma). This constrains the appearance of the euarthropod stem lineage to no older than 550 Ma. While each of the major types of fossil evidence (BSTs, trace fossils, and biomineralized preservation) have their limitations and are incomplete in different ways, when taken together they allow a coherent picture to emerge of the origin and subsequent radiation of total group Euarthropoda during the Cambrian.",
    url = "https://doi.org/10.1073/pnas.1719962115",
    doi = "10.1073/pnas.1719962115",
    openalex = "W2803773655",
    references = "doi101016b9780444594259000196, doi101016jcub201509066, doi101016jearscirev201303008, doi101016jearscirev201606008, doi101016jearscirev201707017, doi101016jpalwor200610005, doi101017s000632310000548x, doi101017s1089332600002837, doi101038376053a0, doi101038nature07673, doi101038nature10689, doi101038nature11874, doi101038nature12520, doi101038nature13414, doi101038nature14256, doi101038ncomms3485, doi101073pnas1111784109, doi101098rstb19750033, doi101098rstb20140313, doi101111brv12168, doi101111j10960031201200413x, doi101126science1107765, doi101126science1169514, doi101126science1206375, doi101126science2745287568, doi101144gsjgs14940607, doi101146annurevearth33092203122519, doi101186s1286201710887, doi101666061301, doi10166612056"
}

@book{doi1012705code2018,
    author = "Turland, NJ and Wiersema, JH and Barrie, FR and Greuter, W and Hawksworth, DL and Herendeen, PS and Knapp, S and Kusber, W-H and Li, D-Z and Marhold, K and May, TW and McNeill, J and Monro, AM and Prado, J and Price, MJ and Smith, GF",
    title = "International Code of Nomenclature for algae, fungi, and plants",
    year = "2018",
    journal = "Regnum vegetabile",
    abstract = "The rules that govern the scientific naming of algae, fungi, and plants are revised at the Nomenclature Section of an International Botanical Congress (IBC). This edition of the International Code of Nomenclature for algae, fungi, and plants embodies the decisions of the XIX IBC, which took place in Shenzhen, China in July, 2017. This Shenzhen Code supersedes the Melbourne Code (McNeill \& al. in Regnum Veg. 154. 2012), published six years ago after the XVIII IBC in Melbourne, Australia, and like its five predecessors, it is written entirely in (British) English. The Melbourne Code was translated into Chinese, French, Italian, Japanese, Korean, Portuguese, Spanish, and Turkish; it is anticipated that the Shenzhen Code, too, will become available in several languages. In questions about the meaning of provisions in translated editions of this Code, the English edition is definitive.",
    url = "https://doi.org/10.12705/code.2018",
    doi = "10.12705/code.2018",
    openalex = "W2910637053"
}

@article{doi101130g481161,
    author = "Woltz, Christina R. and Porter, Susannah M. and Agić, Heda and Dehler, Carol M. and Junium, Christopher K. and Riedman, Leigh Anne and Hodgskiss, Malcolm S.W. and Wörndle, Sarah and Halverson, Galen P.",
    title = "Total organic carbon and the preservation of organic-walled microfossils in Precambrian shale",
    year = "2020",
    journal = "Geology",
    abstract = "Abstract Much of our understanding of early eukaryote diversity and paleoecology comes from the record of organic-walled microfossils in shale, yet the conditions controlling their preservation are not well understood. It has been suggested that high concentrations of total organic carbon (TOC) inhibit the preservation of organic fossils in shale, and although this idea is supported anecdotally, it has never been tested. Here we compared the presence, preservational quality, and assemblage diversity of organic-walled microfossils to TOC concentrations of 346 shale samples that span the late Paleoproterozoic to middle Neoproterozoic in age. We found that fossil-bearing samples have significantly lower median TOC values (0.32 wt\%, n = 189) than those containing no fossils (0.72 wt\%, n = 157). Preservational quality, measured by the loss of surface pattern, density of pitting, and deterioration of wall margin, decreases as TOC increases. Species richness negatively correlates with TOC within the ca. 750 Ma Chuar Group (Arizona, USA), but no relationship is observed in other units. These results support the hypothesis that high TOC content either decreases the preservational quality or inhibits the preservation of organic-walled microfossils altogether. However, it is also possible that other causal factors, including sedimentation rate and microbial degradation, account for the correlation between fossil preservation and TOC. We expect that as TOC varies in space and time, so too does the probability of finding well-preserved fossils. A compilation of 13,940 TOC values spanning Earth history suggests significantly higher median TOC levels in Mesoproterozoic versus Neoproterozoic shale, potentially biasing the interpreted pattern of increased eukaryotic diversity in the Tonian.",
    url = "https://doi.org/10.1130/g48116.1",
    doi = "10.1130/g48116.1",
    openalex = "W3118068870",
    references = "doi101016jprecamres201710008, doi101017jpa201657"
}

@article{ou2026beyond,
    author = "Ou, Zhiji and Meng, Fanwei and Willman, Sebastian and Liu, Jiqiang and Hong, Yong",
    title = "Beyond taxonomy: Raman spectroscopy reveals organic complexity in Precambrian-Cambrian microfossils from South China",
    year = "2026",
    journal = "Precambrian Research",
    url = "https://doi.org/10.1016/j.precamres.2026.108057",
    doi = "10.1016/j.precamres.2026.108057",
    openalex = "W7131101997",
    pages = "108057",
    volume = "437",
    references = "doi101016jearscirev2019102936, doi101016jgca200512004, doi101016jprecamres2021106426, doi101021bk19940570ch014, doi101038nature08793, doi101039a904529e, doi101046j15251314200200408x, doi101103physrevb6114095, doi101111iar12057, doi101111j13653121201000956x, doi101111j194551002007tb00581x"
}