Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-23T16:22:45.899Z Has data issue: false hasContentIssue false

A kinetic model of Phanerozoic taxonomic diversity I. Analysis of marine orders

Published online by Cambridge University Press:  08 April 2016

J. John Sepkoski Jr.*
Affiliation:
Department of the Geophysical Sciences, University of Chicago; 5734 South Ellis Ave., Chicago, Illinois 60637

Abstract

A simple equilibrial model for the growth and maintenance of Phanerozoic global marine taxonomic diversity can be constructed from considerations of the behavior of origination and extinction rates with respect to diversity. An initial postulate that total rate of diversification is proportional to number of taxa extant leads to an exponential model for early phases of diversification. This model appears to describe adequately the “explosive” diversification of known metazoan orders across the Precambrian-Cambrian Boundary, suggesting that no special event, other than the initial appearance of Metazoa, is necessary to explain this phenomenon. As numbers of taxa increase, the rate of diversification should become “diversity dependent.” Ecological factors should cause the per taxon rate of origination to decline and the per taxon rate of extinction to increase. If these relationships are modeled as simple linear functions, a logistic description of the behavior of taxonomic diversity through time results. This model appears remarkably consistent with the known pattern of Phanerozoic marine ordinal diversity as a whole. Analysis of observed rates of ordinal origination also indicates these are to a large extent diversity dependent; however, diversity dependence is not immediately evident in rates of ordinal extinction. Possible explanations for this pattern are derived from considerations of the size of higher taxa and from simulations of their diversification. These suggest that both the standing diversity and the pattern of origination of orders may adequately reflect the behavior of species diversity through time; however, correspondence between rates of ordinal and species extinction may deteriorate with progressive loss of information resulting from incomplete sampling of the fossil record.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Alpert, S. P. 1976. Trilobite and star-like trace fossils from the White-Inyo Mountains, California. J. Paleontol. 50:226239.Google Scholar
Anderson, S. 1974. Patterns of faunal evolution. Q. Rev. Biol. 49:311332.CrossRefGoogle ScholarPubMed
Anderson, S. and Anderson, C. S. 1975. Three Monte Carlo models of faunal evolution. Am. Mus. Novit. 2563:16.Google Scholar
Arkell, W. J. 1957. Introduction to Mesozoic Ammonoidea. Pp. L81L129. In: Moore, R. C., ed. Treatise on Invertebrate Paleontology, Pt. L. 490 pp.Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Bakker, R. T. 1977. Tetrapod mass extinctions—a model of the regulation of speciation rates and immigration by cycles of topographic diversity. Pp. 439468. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier, Amsterdam.Google Scholar
Bambach, R. K. 1977. Species richness in marine benthic habitats through the Phanerozoic. Paleobiology. 3:152167.CrossRefGoogle Scholar
Banks, N. L. 1970. Trace fossils from the late Precambrian and Lower Cambrian of Finmark, Norway. Pp. 1934. In: Crimes, T. P. and Harper, J. C.Trace Fossils. 547 pp.Geol. J. Spec. Issue 3. Seel House Press; Liverpool.Google Scholar
Bardack, D. and Zangerl, R. 1968. First fossil lamprey—a record from the Pennsylvanian of Illinois. Science. 162:12651267.CrossRefGoogle ScholarPubMed
Bell, B. M. 1976a. Phylogenetic implications of ontogenetic development in the Class Edrioasteroidea (Echinodermata). J. Paleontol. 50:10011019.Google Scholar
Bell, B. M. 1976b. A study of North American Edrioasteroidea. N.Y. State Mus. Mem. 21, 446 pp.Google Scholar
Bengtson, S. 1970. The Lower Cambrian fossil Tommotia. Lethaia. 3:363392.CrossRefGoogle Scholar
Bengtson, S. 1976. The structure of some Middle Cambrian conodonts and the early evolution of conodont structure and function. Lethaia. 9:185206.Google Scholar
Bengtson, S. 1977. Aspects of problematic fossils in the early Palaeozoic. Acta Universitatis Upsaliensis, No. 415, 71 pp.Google Scholar
Berggren, W. A. 1972. A Cenozoic time-scale—some implications for regional geology and paleobiogeography. Lethaia. 5:195215.CrossRefGoogle Scholar
Bergström, J. 1970. Rusophycus as an indication of Early Cambrian age. Pp. 3542. In: Crimes, T. P. and Harper, J. C., eds. Trace Fossils. 547 pp.Geol. J. Spec. Issue 3. Seel House Press; Liverpool.Google Scholar
Berkner, L. V. and Marshall, L. C. 1964. The history of oxygenic concentration in the earth's atmosphere. Discuss. Faraday Soc. 37:577595.Google Scholar
Berkner, L. V. and Marshall, L. C. 1965. History of major atmospheric components. Proc. Nat. Acad. Sci. USA. 53:12151225.CrossRefGoogle Scholar
Bockelie, T. G. and Yochelson, E. L. 1976. “Worm” tubes from the Valhallfonna Formation, Spitzbergen. Geol. Soc. Am. Abstr. with Program. 8:139.Google Scholar
Boucot, A. J. 1975. Evolution and Extinction Rate Controls. 427 pp. Elsevier; Amsterdam.Google Scholar
Boucot, A. J. 1976. Standing diversity of fossil groups in successive intervals of geologic time viewed in the light of changing levels of provincialism. J. Paleontol. 49:11051111.Google Scholar
Bretsky, P. W. 1973. Evolutionary patterns in the Paleozoic Bivalvia: Documentation and some theoretical considerations. Geol. Soc. Am. Bull. 84:20792096.Google Scholar
Cailleux, A. 1950. Progression géométrique du nombre des espécies et vie en expansion. C.R.S. de la Soc. Geol. de France. 13:222224.Google Scholar
Cailleux, A. 1954. How many species? Evolution. 8:8384.CrossRefGoogle Scholar
Chilingar, G. V. and Bissell, H. J. 1963. Note on possible reason for scarcity of calcareous skeletons of invertebrates in Precambrian formations. J. Paleontol. 37:942943.Google Scholar
Cisne, J. L. 1974. Evolution of the world fauna of aquatic free-living arthropods. Evolution. 28:337366.Google Scholar
Clark, R. B. 1964. Dynamics in Metazoan Evolution. 313 pp. Clarendon Press; Oxford.Google Scholar
Clark, R. B. 1969. Systematics and phylogeny: Annelida, Echiura, Sipuncula. Pp. 168. In: Florkin, M. and Scheer, B. T., eds. Chemical Zoology. V. 4. 548 pp.Academic Press; New York.Google Scholar
Cloud, P. E. 1948. Some problems and patterns of evolution exemplified by fossil invertebrates. Evolution. 2:322350.CrossRefGoogle ScholarPubMed
Cloud, P. E. Jr. 1968. Pre-metazoan evolution and the origins of the Metazoa. Pp. 172. In: Drake, E. T., ed. Evolution and Environment. 470 pp.Yale Univ. Press; New Haven, Conecticut.Google Scholar
Cloud, P. 1973. Pseudofossils: A plea for caution. Geology. 1:123127.Google Scholar
Cloud, P., Wright, J., and Glover, L. III. 1976. Traces of animal life from 620 m.y. old rocks in North Carolina. Am. Sci. 64:396406.Google Scholar
Cody, M. L. 1975. Towards a theory of continental species diversities. Pp. 214257. In: Cody, M. L. and Diamond, J. M., eds. Ecology and Evolution of Communities. 544 pp.Belknap Press; Cambridge, Massachusetts.Google Scholar
Conway Morris, S. 1977a. Aspects of the Burgess Shale fauna, with particular reference to the nonarthropod component. J. Paleontol. 51(Suppl.):78.Google Scholar
Conway Morris, S. 1977b. A redescription of the Middle Cambrian worm Amiskwia saggitiformis Walcott from the Burgess Shale of British Columbia. Paläontol. Z. 51:271287.CrossRefGoogle Scholar
Conway Morris, S. 1977c. Fossil priapulid worms. Palaeontol. Assoc. London, Spec. Pap. Palaeontol., No. 20, 95 pp.Google Scholar
Conway Morris, S. 1978. Laggania cambria Walcott: A composite fossil. J. Paleontol. 52:126131.Google Scholar
Cook, R. E. 1969. Variation in species density of North American birds. Syst. Zool. 18:6384.CrossRefGoogle Scholar
Cowie, J. W. 1961. Contributions to the geology of North Greenland. Medd. Grønland. 164:147.Google Scholar
Cowie, J. W. and Glaessner, M. F. 1975. The Precambrian-Cambrian Boundary: A symposium. Earth-Sci. Rev. 11:209251.CrossRefGoogle Scholar
Cowie, J. W. and Rozanov, A. Yu. 1974. I.U.G.S. Precambrian-Cambrian Boundary working group in Siberia, 1973. Geol. Mag. 111:237252.CrossRefGoogle Scholar
Cowie, J. W., Rushton, A. W. A., and Stubblefield, C. J. 1972. A correlation of Cambrian rocks in the British Isles. Geol. Soc. London, Spec. Rep. No. 2, 42 pp.Google Scholar
Cowie, J. W. and Spencer, A. M. 1970. Trace fossils from the late Precambrian/Lower Cambrian of East Greenland. Pp. 91100. In: Crimes, T. P. and Harper, J. C., eds. Trace Fossils. 547 pp.Geol. J. Spec. Issue 3. Seel House Press; Liverpool.Google Scholar
Crawford, A. R. and Daily, B. 1971. Probable non-synchroneity of late Precambrian glaciations. Nature. 230:111112.Google Scholar
Daily, B. 1972. The base of the Cambrian and the first Cambrian faunas. Univ. Adelaide Centre for Precambrian Res., Spec. Pap. No. 1, pp. 1342.Google Scholar
Eldredge, N. and Gould, S. J. 1972. Punctuated equilibria: An alternative to phyletic gradualism. Pp. 82115. In: Schopf, T. J. M., ed. Models in Paleobiology. 250 pp.Freeman, Cooper & Co.; San Francisco, California.Google Scholar
Fischer, A. G. 1960. Latitudinal variations in organic diversity. Evolution. 14:6481.Google Scholar
Fischer, A. G. 1965. Fossils, early life, and atmospheric history. Proc. Nat. Acad. Sci., U.S.A. 53:12051215.CrossRefGoogle Scholar
Flessa, K. W. 1975. Area, continental drift, and mammalian diversitv. Paleobiology. 1:189194.Google Scholar
Fritz, W. H. 1972. Lower Cambrian trilobites from the Sekwi Formation type section, MacKenzie Mountains, northwestern Canada. Geol. Surv. Can. Bull., No. 212, 58 pp.Google Scholar
Germs, G. B. 1972. New shelly fossils from the Nama Group, South West Africa. Am. J. Sci. 272:752761.CrossRefGoogle Scholar
Glaessner, M. F. 1958. New fossils from the base of the Cambrian in South Australia. Trans. R. Soc. South Aust. 81:185188.Google Scholar
Glaessner, M. F. 1966. Precambrian paleontology. Earth-Sci. Rev. 1:2950.CrossRefGoogle Scholar
Glaessner, M. F. 1968. Biological events and the Precambrian time scale. Can. J. Earth Sci. 5:585590.CrossRefGoogle Scholar
Glaessner, M. F. 1969. Trace fossils from the Precambrian and basal Cambrian. Lethaia. 2:369393.CrossRefGoogle Scholar
Glaessner, M. F. 1971a. The genus Conomedusites Glaessner & Wade and the diversification of the Cnidaria. Paläontol. Z. 45:717.CrossRefGoogle Scholar
Glaessner, M. F. 1971b. Geographic distribution and time range of the Ediacara Precambrian fauna. Geol. Soc. Am. Bull. 82:509514.Google Scholar
Glaessner, M. F. 1972a. Precambrian paleozoology. Univ. Adelaide Centre for Precambrian Res., Spec. Pap. No. 1, pp. 4352.Google Scholar
Glaessner, M. F. 1972b. Precambrian fossils—a progress report. 1968 Proc. IPU, XXIII Int. Geol. Congr. Pp. 377384.Google Scholar
Glaessner, M. F. 1976. Early Phanerozoic annelid worms and their geological and biological significance. J. Geol. Soc. London. 132:259275.CrossRefGoogle Scholar
Glaessner, M. F. and Wade, M. 1966. The late Precambrian fossils from Ediacara, South Australia. Palaeontology. 9:599628.Google Scholar
Glaessner, M. F. and Wade, M. 1971. Praecambridium—a primitive arthropod. Lethaia. 4:7177.Google Scholar
Glaessner, M. F. and Walter, M. R. 1975. New Precambrian fossils from the Arumbera Sandstone, Northern Territory, Australia. Alcheringa. 1:5969.CrossRefGoogle Scholar
Gould, S. J. 1970. Evolutionary paleontology and the science of form. Earth-Sci. Rev. 6:77119.CrossRefGoogle Scholar
Gould, S. J. 1976. The interpretation of diagrams. Nat. Hist. 85(7):1828.Google Scholar
Gould, S. J. 1977. Ontogeny and Phylogeny. 501 pp. Belknap Press; Cambridge, Massachusetts.Google Scholar
Gould, S. J. and Eldredge, N. 1977. Punctuated equilibria: The tempo and mode of evolution reconsidered. Paleobiology. 3:115151.Google Scholar
Gould, S. J., Raup, D. M., Sepkoski, J. J. Jr., Schopf, T. J. M., and Simberloff, D. S. 1977. The shape of evolution: A comparison of real and random clades. Paleobiology. 3:2340.Google Scholar
Greenwood, P. H. 1975. A History of Fishes. 467 pp. Ernest Benn Ltd; London.Google Scholar
Hancock, J. M. 1967. Some Cretaceous-Tertiary marine faunal changes. Pp. 91104. In: Harland, W. B. et al., eds. The Fossil Record. 828 pp.Geol. Soc. London; London.Google Scholar
Harland, W. B. 1964a. Evidence of late Precambrian glaciation and its significance. Pp. 119149. In: Nairn, A. E. M., ed. Problems in Palaeoclimatology. 705 pp.Wiley; New York.Google Scholar
Harland, W. B. 1964b. Critical evidence for a great Infra-Cambrian glaciation. Geol. Rundsch. 54:4561.CrossRefGoogle Scholar
Harland, W. B. 1974. The Pre-Cambrian-Cambrian Boundary. Pp. 1542. In: Holland, C. H., ed. Cambrian of the British Isles, Norden, and Spitsbergen. 300 pp.Wiley; New York.Google Scholar
Harland, W. B. et al., eds. 1967. The Fossil Record. 828 pp. Geol. Soc. London; London.Google Scholar
Harland, W. B., Smith, A. G., and Wilcock, B., eds. 1964. The Phanerozoic Time-Scale: A Symposium. 458 pp. Geol. Soc. London; London.Google Scholar
Harrington, H. J. and Moore, R. C. 1956. Protomedusae. Pp. F21F23. In: Moore, R. C., ed. Treatise on Invertebrate Paleontology, Pt. F. 498 pp.Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Hill, D. 1972. Archaeocyatha. Pp. E1E158. In: Teichert, C., ed. Treatise on Invertebrate Paleontology, Pt. E (revised). V. 1, 158 pp.Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Hofmann, H. J. 1971. Precambrian fossils, pseudofossils and problematica in Canada. Geol. Surv. Can. Bull. No. 189. 146 pp.Google Scholar
Hupé, P. 1960. Sur le cambrien inférieur du Maroc. 21st Int. Geol. Cong., Copenhagen. Rep., Pt. 8, pp. 7585.Google Scholar
Hutchinson, G. E. 1961. The biologist poses some problems. Pp. 8594. In: Sears, M., ed. Oceanography. Am. Assoc. Adv. Sci., Publ. 67. 654 pp.Google Scholar
Jaeger, W. and Martinsson, A. 1967. Remarks on the problematic fossil Xenusion auerswaldae. Geol. fören. Stockholm förh. 88:435452.CrossRefGoogle Scholar
Jeletsky, J. A. 1965. Taxonomy and phylogeny of fossil Coleoidea (= Dibranchiata). Geol. Surv. Can. Pap. 65-2:7276.Google Scholar
Jell, P. A. 1974. Faunal provinces and planetary reconstruction of the Middle Cambrian. J. Geol. 82:319350.Google Scholar
Jell, P. A. and Jell, J. S. 1976. Early Middle Cambrian corals from western South Wales. Alcheringa. 1:181195.Google Scholar
Johnson, G. A. L., Sutton, I. D., Taylor, F. M., and Thomas, G. 1967. Coelenterata. Pp. 347378. In: Harland, W. B. et al., eds. The Fossil Record. 828 pp.Geol. Soc. London; London.Google Scholar
Johnson, R. G. and Richardson, E. S. Jr. 1968. The Essex Fauna and Medusae. Fieldiana: Geol. 12:109115.Google Scholar
Jones, D. and Thompson, I. 1977. Echiura from the Pennsylvanian of northern Illinois. Lethaia. 10:317325.CrossRefGoogle Scholar
Kukalová-Peck, J. 1973. A Phylogenetic Tree of the Animal Kingdom (Including Orders and Higher Categories). 78 pp. Nat. Mus. Can. Publ. Zool. No. 8. Ottawa, Canada.Google Scholar
Lane, A. C. 1917. Lawson's correlation of the pre-Cambrian Era. Am. J. Sci. 43:4248.CrossRefGoogle Scholar
Lillegraven, J. A. 1972. Ordinal and familial diversity of Cenozoic mammals. Taxon. 21:261274.CrossRefGoogle Scholar
Lindström, M. 1970. A suprageneric taxonomy of the conodonts. Lethaia. 3:427445.CrossRefGoogle Scholar
Lochman-Balk, C. and Wilson, J. L. 1958. Cambrian biostratigraphy in North America. J. Paleontol. 32:312350.Google Scholar
MacArthur, R. H. 1969. Patterns of communities in the tropics. Biol. J. Linn. Soc. 1:1930.CrossRefGoogle Scholar
MacArthur, R. H. 1972. Geographical Ecology. 269 pp. Harper & Row; New York.Google Scholar
MacArthur, R. H. and Levins, R. 1967. The limiting similarity, convergence, and divergence of coexisting species. Am. Nat. 101:377385.Google Scholar
MacArthur, R. H. and Wilson, E. O. 1963. An equilibrium theory of insular zoogeography. Evolution. 17:373387.Google Scholar
MacArthur, R. H. and Wilson, E. O. 1967. The Theory of Island Biogeography. Monogr. Population Biol., No. 1. 203 pp. Princeton Univ. Press; Princeton, New Jersey.Google Scholar
Mark, G. A. and Flessa, K. W. 1977. A test for evolutionary equilibria: Phanerozoic brachiopods and Cenozoic mammals. Paleobiology. 3:1722.Google Scholar
Matthews, S. C. and Missarzhevsky, V. V. 1975. Small shelly fossils of late Precambrian and Early Cambrian age: A review of recent work. J. Geol. Soc. London. 131:289304.Google Scholar
May, R. M. 1973. Stability and Complexity in Model Ecosystems. Monogr. Population Biol., No. 6. 236 pp. Princeton Univ. Press; Princeton, New Jersey.Google Scholar
Mayr, E. 1963. Animal Species and Evolution. 767 pp. Belknap Press; Cambridge, Massachusetts.Google Scholar
Mayr, E. 1965. Avifauna: Turnover on islands. Science. 150:15871588.Google Scholar
Moore, R. C. and Strimple, H. L. 1973. Lower Pennsylvanian (Morrowan) crinoids from Arkansas, Oklahoma, and Texas. Univ. Kans. Paleontol. Contrib., Art. 60, 84 pp.Google Scholar
Moore, R. C. and Teichert, C., eds. 1953–1975. Treatise on Invertebrate Paleontology. Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
North, F. K. 1971. The Cambrian of Canada and Alaska. Pp. 219324. In: Holland, C. H., ed. Cambrian of the New World. 456 pp.Wiley; New York.Google Scholar
Nurshall, J. R. 1959. Oxygen as a prerequisite to the origin of the Metazoa. Nature. 183:11701172.Google Scholar
Öpik, A. A. 1967. The Ordian Stage of the Cambrian and its Australian Metadoxidae. Aust. Bur. Mineral Res., Geol. and Geophy., Bull. 92:133169.Google Scholar
Öpik, A. A. 1975. Cymbric Vale fauna of New South Wales and Early Cambrian biostratigraphy. Aust. Bur. Min. Res., Geol. and Geophys., Bull. 159, 74 pp.Google Scholar
Ossian, C. R. 1973. New Pennsylvanian scyphomedusan from western Iowa. J. Paleontol. 47:990995.Google Scholar
Palmer, A. R. 1977. Biostratigraphy of the Cambrian System—a progress report. Annu. Rev. Earth and Planet. Sci. 5:1333.Google Scholar
Paul, C. R. C. 1977. Evolution of primitive echinoderms. Pp. 123158. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Pflug, H. D. 1972. The Phanerozoic-Cryptozoic Boundary and the origin of Metazoa. Proc. 24th Int. Geol. Congr., Montreal, Sec. 1, pp. 5867.Google Scholar
Pojeta, J. Jr. 1975. Fordilla troyensis Barrande and early pelecypod phylogeny. Bull. Am. Paleontol. 67:363384.Google Scholar
Pojeta, J. and Runnegar, B. 1976. The paleontology of rostroconch mollusks and the early history of the phylum Mollusca. U.S. Geol. Surv. Prof. Pap. 968. 88 pp.Google Scholar
Raup, D. M. 1972. Taxonomic diversity during the Phanerozoic. Science. 177:10651071.CrossRefGoogle ScholarPubMed
Raup, D. M. 1975. Taxonomic diversity estimation using rarefaction. Paleobiology. 1:333342.Google Scholar
Raup, D. M. 1976a. Species diversity in the Phanerozoic: A tabulation. Paleobiology. 2:279288.Google Scholar
Raup, D. M. 1976b. Species diversity in the Phanerozoic: An interpretation. Paleobiology. 2:289297.Google Scholar
Raup, D. M. 1977a. Removing sampling biases from taxonomic diversity data. J. Paleontol. 51(Suppl.):21.Google Scholar
Raup, D. M. 1977b. Probabilistic models in evolutionary paleobiology. Am. Sci. 65:5057.Google Scholar
Raup, D. M. 1977c. Stochastic models in evolutionary palaeontology. Pp. 5978. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Raup, D. M. 1978. Cohort analysis of generic survivorship. Paleobiology. 4:115.CrossRefGoogle Scholar
Raup, D. M. and Gould, S. J. 1974. Stochastic simulation and evolution of morphology—towards a nomothetic paleontology. Syst. Zool. 23:305322.CrossRefGoogle Scholar
Raup, D. M., Gould, S. J., Schopf, T. J. M., and Simberloff, D. S. 1973. Stochastic models of phylogeny and the evolution of diversity. J. Geol. 81:525542.Google Scholar
Raymond, P. E. 1935. Pre-Cambrian life. Geol. Soc. Am. Bull. 46:375392.Google Scholar
Repina, L. N. 1972. Biogeography of Early Cambrian of Siberia according to trilobites. 1968 Proc. IPU, XXIII Int. Geol. Congr., pp. 289300.Google Scholar
Resser, C. E. and Howell, B. F. 1938. Lower Cambrian Olenellus Zone of the Appalachians. Geol. Soc. Am. Bull. 49:195248.Google Scholar
Rhoades, D. C. and Morse, J. W. 1971. Evolutionary and ecologic significance of oxygen-deficient marine basins. Lethaia. 4:413428.Google Scholar
Richardson, E. S. Jr. 1966. Wormlike fossil from the Pennsylvanian of Illinois. Science. 151:7576.CrossRefGoogle ScholarPubMed
Ricklefs, R. and Cox, G. 1972. Taxon cycles in West Indian avifauna. Am. Nat. 106:195219.Google Scholar
Rigby, J. K. 1976. Some observations on occurrences of Cambrian Porifera in western North America and their evolution. Pp. 5160. In: Robison, R. A. and Rowell, A. J., eds. Paleontology and Depositional Environments: Cambrian of Western North America. 227 pp.Brigham Young Univ. Geol. Studies. 23(2).Google Scholar
Robison, R. A., Rosova, A. V., Rowell, A. J., and Fletcher, T. P. 1977. Cambrian boundaries and divisions. Lethaia. 10:257262.Google Scholar
Rolfe, W. D. I. 1969. Phyllocarida. Pp. R291R331. In: Moore, R. C., ed. Treatise on Invertebrate Paleontology, Pt. R. V. 1. 650 pp.Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Romer, A. S. 1966. Vertebrate Paleontology. 3rd ed.468 pp. Univ. Chicago Press; Chicago, Illinois.Google Scholar
Rosenzweig, M. L. 1975. On continental steady states of species diversity. Pp. 121140. In: Cody, M. L. and Diamond, J. M., eds. Ecology and Evolution of Communities. 544 pp.Belknap Press; Cambridge, Massachusetts.Google Scholar
Rosenzweig, M. L. 1977. Does the fossil record provide for natural experiments? Paleobiology. 3:322324.Google Scholar
Rowell, A. J. 1977. Early Cambrian brachiopods from the southwestern Great Basin of California and Nevada. J. Paleontol. 51:6885.Google Scholar
Rozanov, A. Yu. 1967. The Cambrian lower boundary problem. Geol. Mag. 104:415434.Google Scholar
Rozanov, A. Yu. and Debrenne, F. 1974. Age of archaeocyathid assemblages. Am. J. Sci. 274:833848.Google Scholar
Rozanov, A. Yu., Missarzhevsky, V. V., Volkova, N. A., Voronova, L. G., Krylov, I. N., Keller, B. M., Korolyuk, I. K., Lendzion, K., Mikhniak, P., Pykhova, N. G., and Sidorov, A. D. 1969. Tommotsky yarus i problema nizhney granitsy Kembria [The Tommotian Stage and the problem of the Cambrian lower boundary]. Trans. Geol. Inst. Acad. Sci. USSR. 206:5380.Google Scholar
Rudwick, M. J. S. 1964. The Infra-Cambrian glaciation and the origin of the Cambrian fauna. Pp. 150155. In: Nairn, A. E. M., ed. Problems in Palaeoclimatology. 705 pp.Wiley; New York.Google Scholar
Runnegar, B. and Jell, P. A. 1976. Australian Middle Cambrian molluscs and their bearing on early molluscan evolution. Alcheringa. 1:109138.CrossRefGoogle Scholar
Rushton, A. W. A. 1974. The Cambrian of Wales and England. Pp. 43121. In: Holland, C. H., ed. Cambrian of the British Isles, Norden, and Spitsbergen. 300 pp.Wiley; New York.Google Scholar
Schopf, J. W. 1975. Precambrian paleobiology: Problems and perspectives. Annu. Rev. Earth and Planet. Sci. 3:213249.Google Scholar
Schopf, J. W., Haugh, B. N., Molnar, R. E., and Satterthwait, D. F. 1973. On the development of metaphytes and metazoans. J. Paleontol. 47:19.Google Scholar
Schopf, T. J. M. 1974. Permo-Triassic extinctions: Relation to sea-floor spreading. J. Geol. 82:129143.Google Scholar
Schopf, T. J. M. 1977. Patterns and themes of evolution among the Bryozoa. Pp. 159207. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Schram, F. R. 1969. The stratigraphic distribution of Paleozoic Eumalacostraca. Fieldiana: Geol. 12:213234.Google Scholar
Schram, F. R. 1973. Pseudocoelomates and a nemertine from the Illinois Pennsylvanian. J. Paleontol. 47:985989.Google Scholar
Schuchert, C. and Dunbar, C. O. 1933. Historical Geology. 241 pp. Wiley; New York.Google Scholar
Sepkoski, J. J. Jr. 1975. Stratigraphic biases in the analysis of taxonomic survivorship. Paleobiology. 1:343355.Google Scholar
Sepkoski, J. J. Jr. 1976. Species diversity in the Phanerozoic: Species-area effects. Paleobiology. 2:298303.Google Scholar
Sepkoski, J. J. Jr. 1977. The enigma of the Cambrian diversification. Geol. Soc. Am. Abstr. with Program. 9:1168.Google Scholar
Simberloff, D. S. 1970. Taxonomic diversity of island biotas. Evolution. 24:2347.Google Scholar
Simberloff, D. S. 1972. Models in biogeography. Pp. 160191. In: Schopf, T. J. M., ed. Models in Paleobiology. 250 pp.Freeman, Cooper & Co.; San Francisco, California.Google Scholar
Simberloff, D. S. 1974. Permo-Triassic extinctions: Effects of area on biotic equilibrium. J. Geol. 82:267274.Google Scholar
Simpson, G. G. 1953. The Major Features of Evolution. 434 pp. Columbia Univ. Press; New York.Google Scholar
Simpson, G. G. 1960. The history of life. Pp. 117180. In: Tax, S., ed. Evolution after Darwin. v. 1. 629 pp.Univ. Chicago Press; Chicago, Illinois.Google Scholar
Simpson, G. G. 1969. The first three billion years of community evolution. Pp. 162177. In: Woodwell, G. M. and Smith, H. H., eds. Diversity and Stability in Ecological Systems. Brookhaven Symp. Biol. No. 22, 264 pp.Google Scholar
Sokolov, B. S. 1972a. Vendian and Early Cambrian Sabelliditida (Pogonophora) of the USSR. 1968 Proc. IPU, XXIII Int. Geol. Congr. pp. 7986.Google Scholar
Sokolov, B. S. 1972b. The Vendian Stage in earth history. Proc. 24th Int. Geol. Congr., Montreal, Sec. 1, pp. 7884.Google Scholar
Sokolov, B. S. 1973. Vendian of northern Eurasia. Pp. 204218. In: Pitcher, M. G., ed. Arctic Geology. 74 pp.Am. Assoc. Pet. Geol.; Tulsa, Oklahoma.Google Scholar
Sokolov, B. S. 1976. Precambrian Metazoa and the Vendian-Cambrian Boundary. Paleontol. J. 10:113.Google Scholar
Sprinkle, J. 1973. Morphology and Evolution of Blastozoan Echinoderms. Spec. Publ. Mus. Comp. Zool., Harvard Univ. 283 pp.Google Scholar
Sprinkle, J. 1976. Biostratigraphy and paleoecology of Cambrian echinoderms from the Rocky Mountains. Pp. 6173. In: Robison, R. A. and Rowell, A. J., eds. Paleontology and Depositional Environments: Cambrian of Western North America. 227 pp.Brigham Young Univ. Geol. Studies. 23(2).Google Scholar
Stanley, S. M. 1973. An ecological theory for the sudden origin of multicellular life in the late Precambrian. Proc. Nat. Acad. Sci., USA. 70:14861489.Google Scholar
Stanley, S. M. 1975. A theory of evolution above the species level. Proc. Nat. Acad. Sci., USA. 72:646650.Google Scholar
Stanley, S. M. 1976a. Ideas on the timing of metazoan diversification. Paleobiology. 2:209219.CrossRefGoogle Scholar
Stanley, S. M. 1976b. Fossil data and the Precambrian-Cambrian evolutionary transition. Am. J. Sci. 276:5676.Google Scholar
Stanley, S. M. 1977a. Trends, rates, and patterns of evolution in the Bivalvia. Pp. 209250. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Stanley, S. M. 1977b. Influence of rates of speciation and extinction on the diversity and evolutionary stability of higher taxa. J. Paleontol. 51(Suppl.):2627.Google Scholar
Stehli, F. G., McAlester, A. L., and Helsley, E. C. 1967. Taxonomic diversity of Recent bivalves and some implications for geology. Geol. Soc. Am. Bull. 78:455466.Google Scholar
Størmer, L. 1955. Merostomata. Pp. P4P41. In: Moore, R. C., ed. Treatise on Invertebrate Paleontology, Pt. P. 181 pp.Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Størmer, L. 1959. Trilobitoidea. Pp. O23O37. In: Moore, R. C., ed. Treatise on Invertebrate Paleontology, Pt. O. 560 pp.Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Taylor, M. E. 1966. Precambrian mollusc-like fossils from Inyo County, California. Science. 153:198201.Google Scholar
Tchernycheva, N. E. 1959. Système Cambrien. Pp. 185244. In: Markovsky, A. P., ed. Structure Géologique de l'U.R.S.S. Tome 1. Stratigraphie (de Saint-Aubin, P. and Roger, J., trans.). 803 pp.Centre National de la Recherche Scientifique; Paris.Google Scholar
Terborgh, J. 1973. On the notion of favorableness in plant ecology. Am. Nat. 107:481501.Google Scholar
Termier, H. and Termier, G. 1976. The Ediacaran fauna and animal evolution. Paleontol. J. 10:264270.Google Scholar
Thayer, C. W. 1974. Environmental and evolutionary stability in bivalve mollusks. Science. 186:828830.Google Scholar
Towe, K. M. 1970. Oxygen-collagen priority and the early metazoan fossil record. Proc. Nat. Acad. Sci., USA. 65:781788.Google Scholar
Valentine, J. W. 1969. Patterns of taxonomic and ecological structure of the shelf benthos during Phanerozoic time. Paleontology. 12:684709.Google Scholar
Valentine, J. W. 1973. Evolutionary Paleoecology of the Marine Biosphere. 511 pp. Prentice-Hall; Englewood Cliffs, New Jersey.Google Scholar
Valentine, J. W. 1977. General paterns of metazoan evolution. Pp. 2757. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Valentine, J. W. and Campbell, C. A. 1975. Genetic regulation and the fossil record. Am. Sci. 63:673680.Google Scholar
Valentine, J. W. and Moores, E. M. 1972. Global tectonics and the fossil record. J. Geol. 80:167184.Google Scholar
van Hinte, J. E. 1976a. A Jurassic time scale. Am. Assoc. Pet. Geol. Bull. 60:489497.Google Scholar
van Hinte, J. E. 1976b. A Cretaceous time scale. Am. Assoc. Petrol. Geol. Bull. 60:498516.Google Scholar
Van Valen, L. 1973a. A new evolutionary law. Evol. Theory. 1:130.Google Scholar
Van Valen, L. 1973b. Are categories in different phyla comparable? Taxon. 22:333373.Google Scholar
Vinogradov, P. O. 1959. The origin of the biosphere. Pp. 2338. In: Oparin, A. I. et al., eds. The Origins of Life on the Earth. V. 1. Clark, F. and Synge, R. L. M., trans. 961 pp.Pergamon Press; New York.Google Scholar
Wade, M. 1969. Medusae from uppermost Precambrian or Cambrian sandstone, central Australia. Palaeontology. 12:351365.Google Scholar
Wade, M. 1970. The stratigraphic distribution of the Ediacara fauna in Australia. Trans. R. Soc. S. Aust. 94:87104.Google Scholar
Wade, M. 1971. Bilateral Precambrian chondrophores from the Ediacaran fauna, South Australia. Proc. R. Soc. Victoria. 84:183188.Google Scholar
Wade, M. 1972. Hydrozoa and Scyphozoa and other medusoids from the Precambrian Ediacara fauna, South Australia. Palaeontology. 15:97225.Google Scholar
Webb, S. D. 1969. Extinction-origination equilibria in late Cenozoic land mammals of North America. Evolution. 23:688702.Google Scholar
Webb, S. D. 1976. Mammalian faunal dynamics of the great American interchange. Paleobiology. 2:220234.Google Scholar
Webby, B. D. 1970. Late Precambrian trace fossils from New South Wales. Lethaia. 3:79109.Google Scholar
Welch, J. R. 1976. Phosphannulus on Paleozoic crinoid stems. J. Paleontol. 50:218225.Google Scholar
Whittaker, R. H. 1975. Communities and Ecosystems, 2nd ed.385 pp. MacMillan Publ. Co., Inc.; New York.Google Scholar
Wilson, E. O. 1969. The species equilibrium. Pp. 3847. In: Woodwell, G. M. and Smith, H. H., eds. Diversity and Stability in Ecological Systems. Brookhaven Symp. Biol., No. 22, 264 pp.Google Scholar
Yochelson, E. L. 1969. Stenothecoida, a proposed new class of Cambrian Mollusca. Lethaia. 2:4962.Google Scholar
Yochelson, E. L. 1975. Discussion of Early Cambrian “molluscs.” J. Geol. Soc. London. 131:661662.Google Scholar
Yochelson, E. L., Pierce, J. W., and Taylor, M. E. 1970. Salterella from the Cambrian of central Nevada. U.S. Geol. Surv. Prof. Pap. 643-H:H1H7.Google Scholar
Young, F. G. 1972. Early Cambrian and older trace fossils from the southern Cordillera of Canada. Can. J. Earth Sci. 9:117.Google Scholar
Zhuravleva, I. T. 1970. Marine faunas and Lower Cambrian stratigraphy. Am. J. Sci. 269:417445.Google Scholar