Student or educator? Sign up with your school email and get 6 months of Pro free.
CoChat
Sign Up
Cited by 387

The DOI matches its Crossref record; 3 of the 3 references it cites were found in a registry or an index.

A kinetic model of Phanerozoic taxonomic diversity II. Early Phanerozoic families and multiple equilibria

Sepkoski, J. John·1979·Paleobiology
DOI 10.1017/s0094837300006539
Open this paper in CoChat — free account

Abstract

The kinetic model of taxonomic diversity predicts that the long-term diversification of taxa within any large and essentially closed ecological system should approximate a logistic process controlled by changes in origination and extinction rates with changing numbers of taxa. This model is tested with a new compilation of numbers of metazoan families known from Paleozoic stages (including stage-level subdivisions of the Cambrian). These data indicate the occurrence of two intervals of logistic diversification within the Paleozoic. The first interval, spanning the Vendian and Cambrian, includes an approximately exponential increase in families across the Precambrian-Cambrian Boundary and a “pseudo-equilibrium” through the Middle and Late Cambrian, caused by diversity-dependent decrease in origination rate and increase in extinction rate. The second interval begins with a rapid re-diversification in the Ordovician, which leads to a tripling of familial diversity during a span of 50 Myr; by the end of the Ordovician diversity attains a new dynamic equilibrium that is maintained, except for several extinction events, for nearly 200 Myr until near the end of the Paleozoic. A “two-phase” kinetic model is constructed to describe this heterogeneous pattern of early Phanerozoic diversification. The model adequately describes the “multiple equilibria,” the asymmetrical history of the “Cambrian fauna,” the extremely slow initial diversification of the later “Paleozoic fauna,” and the combined patterns of origination and extinction in both faunas. It is suggested that this entire pattern of diversification reflects the early success of ecologically generalized taxa and their later replacement by more specialized taxa.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1017/s0094837300006539

Cites

3 of 3 references verified0 citation errors · 0 not checkable

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Show all 3 references

Research works printed but not linked: 162

  1. Nitecki, 1970, North American cyclocrinitid algae, Fieldiana: Geol., 21, 82
  2. Newell, 1952, Periodicity in invertebrate evolution, J. Paleontol., 26, 371
  3. Bayer, 1967, Repetitive benthonic communities in the Maquoketa Formation (Ordovician) of Minnesota, J. Paleontol., 41, 417
  4. Zhuravleva, 1974, Ancient Cnidaria, v. 1, 63
  5. Pitcher, 1964, Evolution of Chazyan (Ordovician) reefs of eastern U.S. and Canada, Can. Petrol. Geol. Bull., 12, 632
  6. Zhuravleva I. T. 1972. Early Cambrian biogeography and geochronology according to the Archaeocyathi. 1968 Proc. IPU, XXIII Int. Geol. Congr., pp. 361–373.
  7. 10.2475/ajs.269.5.417 · DOI
  8. 10.1130/0016-7606(1972)83[2499:CEOTMO]2.0.CO;2 · DOI
  9. Wager, 1964, The Phanerozoic Time-Scale. A Symposium, 13
  10. 10.1130/0091-7613(1978)6<75:COTCBB>2.0.CO;2 · doi:10.1130/0091-7613(1978)6<75:cotcbb>2.0.co;2
  11. 10.1111/j.1502-3931.1968.tb01740.x · DOI
  12. Van Valen, 1973, A new evolutionary law, Evol. Theory., 1, 1
  13. Harland, 1964, The Phanerozoic Time-scale: A Symposium, 458
  14. Taylor, 1968, Review of: The Mindyallan Fauna of Northwestern Queensland, by A, A. Öpik. J. Paleontol., 42, 1319
  15. 10.2475/ajs.276.1.56 · DOI
  16. 10.2307/2412955 · DOI
  17. Wade, 1971, Bilateral Precambrian chondrophores from the Ediacaran fauna, South Australia, Proc. R. Soc. Victoria., 84, 183
  18. 10.1017/S0016756800041133 · DOI
  19. Pojeta, 1976, The paleontology of rostroconch mollusks and the early history of the phylum Mollusca, U.S. Geol. Surv. Prof. Pap., 968, 88
  20. Sokolov, 1976, Precambrian Metazoa and the Vendian-Cambrian Boundary, Paleontol. J., 10, 1
  21. Brown, 1978, Morphologic complexity and its relationship to taxonomic rates of evolution, 139
  22. Robison R. A. 1975. Species diversity among agnostid trilobites. Pp. 219–226. In: Martinsson A. , ed. Evolution and Morphology of the Trilobita, Trilobitoidea and Merstomata. 467 pp. Fossils and Strata No. 4.
  23. Wade, 1972, Hydrozoa and Scyphozoa and other medusoids from the Precambrian Ediacara fauna, South Australia, Palaeontology., 15, 197
  24. 10.1111/j.1502-3931.1977.tb00619.x · DOI
  25. Richter, 1955, Die ältesten Fossilien Süd-Afrikas, Senckenberg. Leth., 36, 243
  26. Repina, 1974, Biostratigrafiya i Paleontologiya Nizhnego Kembriya Evropy i Severnoy Asii, 76
  27. 10.1126/science.177.4054.1065 · DOI · Paper page
  28. Valentine, 1973, Evolutionary Paleoecology of the Marine Biosphere, 511
  29. Paul, 1977, Patterns of Evolution, 124
  30. 10.1111/j.1502-3931.1977.tb00608.x · doi:10.1111/j.1502-3931.1977.tb00608.x
  31. 10.1146/annurev.ea.05.050177.000305 · DOI
  32. Harland, 1967, The Fossil Record, 828
  33. Raup, 1978, Principles of Paleontology, 481
  34. Öpik, 1975, Cymbric Vale fauna of New South Wales and Early Cambrian biostratigraphy, Aust. Bur. Miner. Res., Geol. and Geophys., Bull., 159, 1
  35. Pojeta J. 1971. Review of Ordovician pelecypods. U.S. Geol. Surv. Prof. Pap. 695, 46 pp. · doi:10.3133/pp695
  36. 10.1080/03115517608619064 · DOI · Paper page
  37. Öpik, 1966, The early Upper Cambrian crisis and its correlation, J. Proc. R. Soc. New S. Wales., 100, 9, 10.5962/p.360891 · DOI
  38. 10.1017/S0094837300005649 · DOI · Paper page
  39. Öpik, 1967b, The Mindyallan fauna of north-western Queensland, Aust. Bur. Miner. Res., Geol. and Geophys., Bull., 74, 571
  40. 10.1007/BF02989671 · DOI
  41. Simpson, 1953, The Major Features of Evolution, 434, 10.7312/simp93764 · DOI · Paper page
  42. Nalivkin, 1973, Geology of the U.S.S.R., 855
  43. 10.1016/S0016-6995(79)80106-0 · DOI
  44. McBride, 1976, Paleontology and Depositional Environments: Cambrian of Western North America, 139
  45. 10.1126/science.186.4161.311 · DOI · Paper page
  46. 10.1144/gsjgs.131.3.0289 · DOI
  47. Martinsson, 1974, Cambrian of the British Isles, Norden and Spitsbergen, 185
  48. 10.1126/science.159.3820.1231 · DOI
  49. MacArthur, 1967, The Theory of Island Biogeography, 203
  50. 10.1111/j.1558-5646.1963.tb03295.x · DOI · Paper page
  51. 10.1126/science.204.4390.335 · DOI
  52. Lochman-Balk, 1958, Cambrian biostratigraphy in North America, J. Paleontol., 32, 312
  53. 10.1017/S0094837300002232 · DOI
  54. Walker, 1973, Major Middle Ordovician reef tract in east Tennessee, Am. J. Sci., 273A, 294
  55. Bergström, 1973, Organization, life, and systematics of trilobites, Fossils and Strata, No., 2, 69
  56. 10.1111/j.1502-3931.1978.tb01295.x · DOI
  57. Rozanov, 1969, Tommotsky yarus i problema nizhney granitsy Kembria, Trans. Geol. Inst. Acad. Sci. USSR., 206, 5
  58. 10.1016/0031-0182(69)90003-0 · DOI
  59. Moore, 1953-1979, Treatise on Invertebrate Paleontology
  60. Levinton, 1974, Trophic group and evolution in bivalve molluscs, Palaeontology., 17, 579
  61. Palmer, 1971, Cambrian of the New World, 1
  62. Newell, 1967, Revolutions in the history of life, Geol. Soc. Am. Spec. Pap., 89, 63
  63. Fritz W. H. 1972. Lower Cambrian trilobites from the Sekwi Formation type section, MacKenzie Mountains, northwestern Canada. Can. Geol. Surv. Bull. No. 212, 58 pp. · DOI
  64. Boucot, 1975b, Evolution and Extinction Rate Controls, 427
  65. Pitcher, 1971, Middle Ordovician reef assemblages, 1341
  66. Cowie, 1978, The Geologic Time Scale, 355
  67. Rowell, 1977, Early Cambrian brachiopods from the southwestern Great Basin of California and Nevada, J. Paleontol., 51, 68
  68. 10.1016/0012-8252(75)90120-8 · DOI
  69. 10.1017/S0094837300005236 · DOI · Paper page
  70. Harrington, 1956, Treatise on Invertebrate Paleontology, Pt. F. Coelenterata, F24
  71. Robison, 1960, Lower and Middle Cambrian stratigraphy of the eastern Great Basin, 43
  72. Briggs, 1977, Evolutionary significance of Canadaspis, the earliest positively identified crustacean, J. Paleontol., 51, 4
  73. Hudson, 1964, The Phanerozoic Time-scale: A Symposium, 37
  74. Hupé P. 1960. Sur le cambrien inférieur du Maroc. 21st Int. Geol. Congr., Copenhagen. Rep., Pt. 8, pp. 75–85.
  75. 10.1080/00206817809471441 · doi:10.1080/00206817809471441
  76. 10.1130/0016-7606(1975)86<881:MCSOTH>2.0.CO;2 · doi:10.1130/0016-7606(1975)86<881:mcsoth>2.0.co;2
  77. Öpik, 1967a, The Ordian Stage of the Cambrian and its Australian Metadoxididae, Aust. Bur. Miner. Res., Geol. and Geophys., Bull., 92, 133
  78. Sokolov B. S. 1972. The Wendian Stage in Earth history. 24th Int. Geol. Congr., Montreal, Sec. 1, pp. 78–84.
  79. 10.1111/j.1502-3931.1970.tb00829.x · DOI · Paper page
  80. Palmer, 1969, North Atlantic—Geology and Continental Drift, 139
  81. Kobayashi, 1971, The Cambro-Ordovician faunal provinces and the interprovincial correlation, J. Fac. Sci., Univ. Tokyo, Sec. 11., 18, 129
  82. Conway Morris, 1977a, A new entoproct-like organism from the Burgess Shale of British Columbia, Palaeontology., 20, 833
  83. 10.1017/S009483730000508X · DOI · Paper page
  84. Palmer A. R. 1956. The Cambrian System of the Great Basin in western United States. Pp. 663–681. In: Rodgers J. , ed. El Sistema Cámbrico. Pt. 2. 20th Int. Geol. Congr.; México.
  85. Zhuravleva, 1972, Paleontologija Miezdunarod Geol, 7
  86. Glaessner, 1958b, New fossils from the base of the Cambrian in South Australia, Trans. R. Soc. S. Aust., 81, 185
  87. Gritsik, 1969, Biostratigrafiya i Paleontologiya Nizhnego Kembriya Sibiri i Dalbiego Vostoka, 186
  88. 10.1130/0016-7606(1971)82[509:GDATRO]2.0.CO;2 · DOI
  89. McKerrow, 1978, The Ecology of Fossils, 384
  90. Blalock, 1964, Causal Inferences in Nonexperimental Research, 200
  91. Alpert, 1977, Trace Fossils 2, 1
  92. Pflug H. D. 1972. The Phanerozoic-Cryptozoic Boundary and the origin of Metazoa. 24th Int. Geol. Congr., Montreal, Sec. 1, pp. 58–67.
  93. 10.1017/S0094837300004917 · DOI · Paper page
  94. Bengtson, 1977b, Early Cambrian button-shaped phosphatic microfossils from the Siberian Platform, Palaeontology., 20, 751
  95. Bengtson, 1977a, Aspects of problematic fossils in the early Palaeozoic, 71
  96. Alpert, 1976, Trilobite and star-like trace fossils from the White-Inyo Mountains, California, J. Paleontol., 50, 226
  97. 10.5962/bhl.title.4489 · DOI · Paper page
  98. Gould, 1977, Patterns of Evolution, 1
  99. Sprigg, 1947, Early Cambrian (?) jellyfishes from the Flinders Ranges, South Australia, Trans. R. Soc. S. Aust., 71, 219
  100. 10.1017/S0094837300005972 · DOI · Paper page
  101. 10.1139/e77-142 · doi:10.1139/e77-142
  102. Cutbill, 1967, The Fossil Record, 791
  103. 10.1017/S0016756800041145 · doi:10.1017/s0016756800041145
  104. 10.1139/e72-151 · DOI
  105. Cloud, 1968, Evolution and Environment, 1
  106. Rushton, 1974, Cambrian of the British Isles, Norden and Spitsbergen, 43
  107. Conway Morris, 1977b, A new metazoan from the Cambrian Burgess Shale of British Columbia, Palaeontology., 20, 623
  108. 10.1144/transed.17.3.183 · DOI · Paper page
  109. Cowie, 1964, The Phanerozoic Time-Scale: A Symposium, 255
  110. Palmer, 1965, Biomere, a new kind of biostratigraphic unit, J. Paleontol., 39, 149
  111. North, 1971, Cambrian of the New World, 219
  112. 10.1038/228657a0 · DOI · Paper page
  113. Lochman-Balk, 1971, Cambrian of the New World, 79
  114. Lambert, 1971, The Phanerozoic Time-scale, A Supplement, 9
  115. 10.1080/03115517608619070 · DOI
  116. Aitken, 1966, Middle Cambrian to Middle Ordovician cyclic sedimentation, southern Rocky Mountains of Alberta, Can. Petrol. Geol. Bull., 14, 405
  117. 10.1111/j.1558-5646.1969.tb03551.x · DOI
  118. 10.1126/science.203.4379.458 · DOI · Paper page
  119. Daily, 1975, The trilobite Lejopyge Hawle and Corda and the Middle-Upper Cambrian Boundary, Palaeontology., 18, 527
  120. 10.1017/S0016756800041157 · DOI
  121. Stitt, 1971, Repeating evolutionary pattern in Late Cambrian trilobite biomeres, J. Paleontol., 45, 178
  122. Boucot, 1975a, Standing diversity of fossil groups in successive intervals of geologic time viewed in the light of changing levels of provincialism, J. Paleontol., 49, 1105
  123. 10.1007/BF01800671 · DOI
  124. Tchernycheva, 1959, Structure Géologique de l'U.R.S.S. Tome 1. Stratigraphie, 185
  125. Öpik, 1968, Ordian (Cambrian) Crustacea Bradoriida of Australia, Aust. Bur. Miner. Res., Geol. and Geophys., Bull., 103, 1
  126. Fritz, 1970, Geology and Economic Minerals of Canada, 593
  127. Nitecki, 1972, North American Silurian receptaculitid algae, Fieldiana: Geol., 28, 108
  128. Valentine, 1972, Models in Paleobiology, 192
  129. Richards, 1972, Autecology of Richmondian brachiopods (Late Ordovician) of Indiana and Ohio, J. Paleontol., 46, 386
  130. Fedonkin, 1977, Trace Fossils 2, 183
  131. Harper, 1975, Standing diversity of fossil groups in successive intervals of geologic time: A new measure, J. Paleontol., 49, 752
  132. Tchernycheva, 1965, Kembriyskaya Sistem, 596
  133. Salop, 1977, Precambrian of the Northern Hemisphere, 378
  134. 10.2307/1931976 · DOI · Paper page
  135. Hill, 1972, Treatise on Invertebrate Paleontology, v. 1, 158
  136. Kobayashi, 1966, The Cambro-Ordovician formations and faunas of South Korea. Part X. Stratigraphy of the Chosen Group in Korea and South Manchuria. Section B. The Chosen Group of North Korea and northeast China, J. Fac. Sci., Univ. Tokyo, Sec. 11., 16, 209
  137. 10.1086/627905 · DOI · Paper page
  138. 10.2475/ajs.274.8.833 · DOI
  139. 10.1017/S0094837300005819 · doi:10.1017/s0094837300005819
  140. Glaessner, 1966, The late Precambrian fossils from Ediacara, South Australia, Palaeontology., 9, 599
  141. Stanley, 1977, Patterns of Evolution, 209
  142. Daily, 1972, The base of the Cambrian and the first Cambrian faunas, 13
  143. 10.1017/S0016756800038486 · DOI
  144. Simpson, 1944, Tempo and Mode in Evolution, 237
  145. Cowie, 1972, A correlation of Cambrian rocks in the British Isles, Geol. Soc. London, Spec. Rept., 2, 42
  146. Wade, 1969, Medusae from uppermost Precambrian or Cambrian sandstones, central Australia, Palaeontology., 12, 351
  147. Armstrong, 1978, The Geologic Time Scale, 73
  148. 10.1111/j.1558-5646.1974.tb00757.x · DOI
  149. Pojeta, 1975, Fordilla troyensis Barrande and early pelecypod phylogeny, Bull. Amer. Paleontol., 67, 363
  150. 10.1111/j.1502-3931.1971.tb01280.x · DOI
  151. Sprinkle, 1976, Paleontology and Depositional Environments: Cambrian of Western North America, 61
  152. 10.1111/j.1095-8312.1969.tb01809.x · DOI · Paper page
  153. Sokolov, 1973, Arctic Geology, 204
  154. Whittington, 1966, Phylogeny and distribution of Ordovician trilobites, J. Paleontol., 40, 696
  155. 10.1086/627388 · DOI
  156. Rosenzweig, 1975, Ecology and Evolution of Communities, 121
  157. Walker, 1970, Congruent fossil communities from Ordovician and Devonian carbonates of New York, J. Paleontol., 44, 928
  158. 10.1017/S0094837300006035 · DOI
  159. Williams, 1969, The Pre-Cambrian and Lower Paleozoic Rocks of Wales, 117
  160. Taylor, 1977, Concepts and Methods of Biostratigraphy, 397
  161. Cloud, 1976, Major features of crustal evolution, Geol. Soc. South Afr. Trans. Annexure, Vol. 79, 32
  162. Stitt J. H. 1975. Adaptive radiation, trilobite paleoecology, and extinction, Ptychaspidid Biomere, Late Cambrian of Oklahoma. Pp. 381–390. In: Martinsson A. , ed. Evolution and Morphology of the Trilobita, Trilobitoidea and Merostomata. 467 pp. Fossils and Strata No. 4.

Cited by

See all 387

Metadata

Authors
Sepkoski, J. J.
Venue
Paleobiology
Publisher
Cambridge University Press (CUP)
Published
1979
Volume
5
Issue
3
Pages
222-251
ISSN
  • 0094-8373 (ISSN-L)
  • 1938-5331
DOI
10.1017/s0094837300006539
OpenAlex
W2504649407
Cited by
387
References
3
FWCI
16.24
Type
journal article
Language
en
Open access
closed
Licence
www.cambridge.org/core/terms (unspecified, 13552 d)

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

How to cite

Cite CoChat for the checks on this page, and the paper for its own findings.

This page
CoChat. (2026). Citation check: A kinetic model of Phanerozoic taxonomic diversity II. Early Phanerozoic families and multiple equilibria. https://app.cochat.ai/papers/10.1017/s0094837300006539
The paper
Sepkoski, J. J. (1979). A kinetic model of Phanerozoic taxonomic diversity II. Early Phanerozoic families and multiple equilibria. Paleobiology. https://doi.org/10.1017/s0094837300006539

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.