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Within- and among-genus components of size evolution during mass extinction, recovery, and background intervals: a case study of Late Permian through Late Triassic foraminifera

Published online by Cambridge University Press:  08 February 2016

Brianna L. Rego
Affiliation:
Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305, United States of America. E-mail: [email protected]
Steve C. Wang
Affiliation:
Department of Mathematics and Statistics, Swarthmore College, Swarthmore, Pennsylvania 19081, United States of America, and Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305, United States of America
Demir Altiner
Affiliation:
Department of Geological Engineering, Middle East Technical University, Ankara 06531, Turkey, and Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305, United States of America
Jonathan L. Payne*
Affiliation:
Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305, United States of America. E-mail: [email protected]
*
∗∗Corresponding author

Abstract

One of the best-recognized patterns in the evolution of organismal size is the tendency for mean and maximum size within a clade to decrease following a major extinction event and to increase during the subsequent recovery interval. Because larger organisms are typically thought to be at higher extinction risk than their smaller relatives, it has commonly been assumed that size reduction mostly reflects the selective extinction of larger species. However, to our knowledge the relative importance of within- and among-lineage processes in driving overall trends in body size has never been compared quantitatively. In this study, we use a global, specimen-level database of foraminifera to study size evolution from the Late Permian through Late Triassic. We explicitly decompose size evolution into within- and among-genus components. We find that size reduction following the end-Permian mass extinction was driven more by size reduction within surviving species and genera than by the selective extinction of larger taxa. Similarly, we find that increase in mean size across taxa during Early Triassic biotic recovery was a product primarily of size increase within survivors and the extinction of unusually small taxa, rather than the origination of new, larger taxa. During background intervals we find no strong or consistent tendency for extinction, origination, or within-lineage change to move the overall size distribution toward larger or smaller sizes. Thus, size stasis during background intervals appears to result from small and inconsistent effects of within- and among-lineage processes rather than from large but offsetting effects of within- and among-taxon components. These observations are compatible with existing data for other taxa and extinction events, implying that mass extinctions do not influence size evolution by simply selecting against larger organisms. Instead, they appear to create conditions favorable to smaller organisms.

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Articles
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Copyright © The Paleontological Society 

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References

Literature Cited

Alroy, J. 1998. Cope's rule and the dynamics of body mass evolution in North American fossil mammals. Science 280:731734.CrossRefGoogle ScholarPubMed
Apthorpe, M. 2003. Early to lowermost Middle Triassic Foraminifera from the Locker Shale of Hampton-1 well, Western Australia. Journal of Micropalaeontology 22:127.CrossRefGoogle Scholar
Arnold, A. J., Kelly, D. C., and Parker, W. C. 1995. Causality and Cope's rule: evidence from the planktonic foraminifera. Journal of Paleontology 69:203210.CrossRefGoogle Scholar
Arthur, M. A., Zachos, J. C., and Jones, D. S. 1987. Primary productivity and the Cretaceous/Tertiary boundary event in the oceans. Cretaceous Research 8:4354.CrossRefGoogle Scholar
Bambach, R. K., Knoll, A. H., and Sepkoski, J. J. Jr. 2002. Anatomical and ecological constraints on Phanerozoic animal diversity in the marine realm. Proceedings of the National Academy of Sciences USA 99:68546859.CrossRefGoogle ScholarPubMed
Benton, M. J., and Twitchett, R. J. 2003. How to kill (almost) all life: the end-Permian extinction event. Trends in Ecology and Evolution 18:358365.CrossRefGoogle Scholar
Borths, M. 2008. Crinoids in Lilliput: Morphological change in class Crinoidea across the Ordovician-Silurian boundary. B.S. The Ohio State University, Colombus, Oh.Google Scholar
Brown, J. H. 1995. Macroecology. University of Chicago Press, Chicago.Google Scholar
Brown, J. H., Marquet, P. A., and Taper, M. L. 1993. Evolution of body size: consequences of an energetic definition of fitness. American Naturalist 142:573584.CrossRefGoogle ScholarPubMed
Budd, A. F., and Johnson, K. G. 1991. Size-related evolutionary patterns among species and subgenera in the Strombina group (Gastropoda: Columbellidae). Journal of Paleontology 65:417434.CrossRefGoogle Scholar
Cao, C., Love, G. D., Hays, L. E., Wang, W., Shen, S., and Summons, R. E. 2009. Biogeochemical evidence for euxinic oceans and ecological disturbance presaging the end-Permian mass extinction event. Earth and Planetary Science Letters 281:188201.CrossRefGoogle Scholar
Clapham, M. E., and Payne, J. L. 2011. Acidification, anoxia, and extinction: a multiple regression analysis of extinction selectivity during the Middle and Late Permian. Geology 39:10591062.CrossRefGoogle Scholar
Clauset, A., and Erwin, D. H. 2008. The evolution and distribution of species body size. Science 321:399401.CrossRefGoogle ScholarPubMed
Clémence, M.-E., Bartolini, A., Gardin, S., Paris, G., Beaumont, V., and Page, K. N. 2010. Early Hettangian benthic-planktonic coupling at Doniford (SW England): palaeoenvironmental implications for the aftermath of the end-Triassic crisis. Palaeogeography, Palaeoclimatology, Palaeoecology 295:102115.CrossRefGoogle Scholar
Damuth, J. 1991. Ecology—of size and abundance. Nature 351:268269.CrossRefGoogle Scholar
D'Hondt, S., Donaghay, P., Zachos, J. C., Luttenberg, D., and Lindinger, M. 1998. Organic carbon fluxes and ecological recovery from the Cretaceous-Tertiary mass extinction. Science 282:276279.CrossRefGoogle ScholarPubMed
Erwin, D. H. 2006. Extinction: how life on Earth nearly ended 250 million years ago. Princeton University Press, Princeton, N.J.Google Scholar
Finkel, Z. V., Katz, M. E., Wright, J. D., Schofield, O. M. E., and Falkowski, P. G. 2005. Climatically driven macroevolutionary patterns in the size of marine diatoms of the Cenozoic. Proceedings of the National Academy of Sciences USA 102:89278932.CrossRefGoogle ScholarPubMed
Finkel, Z. V., Sebbo, J., Feist-Burkhardt, S., Irwin, A. J., Katz, M. E., Schofield, O. E. M., Young, J. R., and Falkowski, P. G. 2007. A universal driver of macroevolutionary change in the size of marine phytoplankton over the Cenozoic. Proceedings of the National Academy of Sciences USA 104:2041620420.CrossRefGoogle ScholarPubMed
Finnegan, S., Payne, J. L., and Wang, S. C. 2008. The Red Queen revisited: reevaluating the age selectivity of Phanerozoic marine genus extinctions. Paleobiology 34:318341.CrossRefGoogle Scholar
Finnegan, S., Bergmann, K., Eiler, J. M., Jones, D. S., Fike, D. A., Eisenman, I., Hughes, N. C., Tripati, A. K., and Fischer, W. W. 2011. The magnitude and duration of Late Ordovician-Early Silurian glaciation. Science 331:903906.CrossRefGoogle ScholarPubMed
Fraiser, M. L., and Bottjer, D. J. 2004. The non-actualistic Early Triassic gastropod fauna: a case study of the Lower Triassic Sinbad Limestone member. Palaios 19:259275.2.0.CO;2>CrossRefGoogle Scholar
Ganino, C., and Arndt, N. T. 2009. Climate changes caused by degassing of sediments during the emplacement of large igneous provinces. Geology 37:323326.CrossRefGoogle Scholar
Gazdzicki, A. 1983. Foraminifers and biostratigraphy of Upper Triassic and Lower Jurassic of the Slovakian and Polish Carpathians. Palaeontologia Polonica 44:109169.Google Scholar
Grice, K., Cao, C. Q., Love, G. D., Bottcher, M. E., Twitchett, R. J., Grosjean, E., Summons, R. E., Turgeon, S. C., Dunning, W., and Jin, Y. G. 2005. Photic zone euxinia during the Permian-Triassic superanoxic event. Science 307:706709.CrossRefGoogle ScholarPubMed
Groves, J. R., Rettori, R., Payne, J. L., Boyce, M. D., and Altiner, D. 2007. End-Permian mass extinction of Lagenide foraminifers in the southern Alps (northern Italy). Journal of Paleontology 81:415434.CrossRefGoogle Scholar
Haig, D. W., McCartain, E., Barber, L., and Backhouse, J. 2007. Triassic-Lower Jurassic foraminiferal indices for Bahaman-type carbonate-bank limestones, Cablac Mountain, East Timor. Journal of Foraminiferal Research 37:248264.CrossRefGoogle Scholar
Hallam, A. 1975. Evolutionary size increase and longevity in Jurassic bivalves and ammonites. Nature 258:493496.CrossRefGoogle Scholar
Hallock, P. 1985. Why are larger foraminifera large? Paleobiology 11:195208.CrossRefGoogle Scholar
Harper, E. M., Peck, L. S., and Hendry, K. R. 2009. Patterns of shell repair in articulate brachiopods indicate size constitutes a refuge from predation. Marine Biology 156:19932000.CrossRefGoogle Scholar
Hauser, M., Martini, R., Burns, S., Dumitrica, P., Krystyn, L., Matter, A., Peters, T., and Zaninetti, L. 2001. Triassic stratigraphic evolution of the Arabian–Greater India embayment of the southern Tethys margin. Eclogae Geologicae Helvetiae 94:2962.Google Scholar
He, W.-H., Twitchett, R. J., Zhang, Y., Shi, G. R., Feng, Q.-L., Yu, J.-X., Wu, S.-B., and Peng, X.-F. 2010. Controls on body size during the Late Permian mass extinction event. Geobiology 8:391402.CrossRefGoogle ScholarPubMed
Holland, C. H., and Copper, P. 2008. Ordovician and Silurian nautiloid cephalopods from Anticosti Island: traject across the Ordovician-Silurian (O-S) mass extinction boundary. Canadian Journal of Earth Sciences 45:10151038.CrossRefGoogle Scholar
Huang, B., Harper, D. A. T., Zhan, R., and Rong, J. 2010. Can the Lilliput Effect be detected in the brachiopod faunas of South China following the terminal Ordovician mass extinction? Palaeogeography, Palaeoclimatology, Palaeoecology 285:277286.CrossRefGoogle Scholar
Hunt, G., and Roy, K. 2006. Climate change, body size evolution, and Cope's rule in deep-sea ostracodes. Proceedings of the National Academy of USA 103:13471352.CrossRefGoogle ScholarPubMed
Hunt, G., Wicaksono, S. A., Brown, J. E., and Macleod, K. G. 2010. Climate-driven body-size trends in the ostracod fauna of the deep Indian Ocean. Palaeontology 53:12551268.CrossRefGoogle Scholar
Inselberg, A. 1985. The plane with parallel coordinates. Visual Computer 1:6991.CrossRefGoogle Scholar
Jablonski, D. 1986. Background and mass extinctions: the alternation of macroevolutionary regimes. Science 231:129133.CrossRefGoogle ScholarPubMed
Jablonski, D. 1997. Body-size evolution in Cretaceous molluscs and the status of Cope's rule. Nature 385:250252.CrossRefGoogle Scholar
Jablonski, D. 2005. Mass extinctions and macroevolution. InVrba, E. S. and Eldredge, N., eds. Macroevolution: diversity, disparity, contingency. Paleobiology 31 (Suppl. to No. 2):192210.Google Scholar
Jablonski, D., and Raup, D. M. 1995. Selectivity of end-Cretaceous marine bivalve extinctions. Science 268:389391.CrossRefGoogle ScholarPubMed
Kaiho, K. 1998. Global climatic forcing of deep-sea benthic foraminiferal test size during the past 120 m.y. Geology 26:491494.2.3.CO;2>CrossRefGoogle Scholar
Kiessling, W., and Simpson, C. 2011. On the potential for ocean acidification to be a general cause of ancient reef crises. Global Change Biology 17:5667.CrossRefGoogle Scholar
Kobayashi, F. 1997. Upper Permian foraminifers from the Iwai-Kanyo area, West Tokyo, Japan. Journal of Foraminiferal Research 27:186195.CrossRefGoogle Scholar
Kobayashi, F. 2005. Permian foraminifers from the Itsukaichi-Ome area, west of Tokyo, Japan. Journal of Paleontology 79:413432.2.0.CO;2>CrossRefGoogle Scholar
Kobayashi, F., Martini, R., and Zaninetti, L. 2005. Anisian foraminifers from allochthonous limestones of the Tanoura formation (Kurosegawa Terrane, West Kyushu, Japan). Géobios 38:751763.CrossRefGoogle Scholar
Kristan-Tollmann, E. 1986. Foraminiferen aus dem rhaetischen Kuta-Kalk von Papua/Neuguinea. Mitteilungen der Oesterreichischen Geologischen Gesellschaft 78:291317.Google Scholar
Leven, E. J., and Okay, A. I. 1996. Foraminifera from the exotic Permo-Carboniferous limestone blocks in the Karakaya Complex, Northwestern Turkey. Rivista Italiana di Paleontologia e Stratigrafia 102:139174.Google Scholar
Lockwood, R. 2005. Body size, extinction events, and the early Cenozoic record of veneroid bivalves: a new role for recoveries? Paleobiology 31:578590.CrossRefGoogle Scholar
Luo, G., Wang, Y., Algeo, T. J., Kump, L. R., Bai, X., Yang, H., Yao, L., and Xie, S. 2011. Enhanced nitrogen fixation in the immediate aftermath of the latest Permian marine mass extinction. Geology 39:647650.CrossRefGoogle Scholar
Mancinelli, A., Chiocchini, M., Chiocchini, R. A., and Romano, A. 2005. Biostratigraphy of Upper Triassic - Lower Jurassic carbonate platform sediments of the Central-Southern Apennines (Italy). Rivista Italiana di Paleontologia e Stratigrafia 111:271283.Google Scholar
McGhee, G. R., Sheehan, P. M., Bottjer, D. J., and Droser, M. L. 2004. Ecological ranking of Phanerozoic biodiversity crises: ecological and taxonomic severities are decoupled. Palaeogeography, Palaeoclimatology, Palaeoecology 211:289297.CrossRefGoogle Scholar
McRoberts, C. A., and Newton, C. R. 1995. Selective extinction among end-Triassic European bivalves. Geology 23:102104.2.3.CO;2>CrossRefGoogle Scholar
Metcalfe, B., Twitchett, R. J., and Price-Lloyd, N. 2011. Changes in size and growth rate of ‘Lilliput' animals in the earliest Triassic. Palaeogeography, Palaeoclimatology, Palaeoecology 308:171180.CrossRefGoogle Scholar
Meyer, K. M., Kump, L. R., and Ridgwell, A. 2008. Biogeochemical controls on photic-zone euxinia during the end-Permian mass extinction. Geology 36:747750.CrossRefGoogle Scholar
Meyer, K. M., Jost, A. B., Yu, M., and Payne, J. L. 2011. δ13C evidence that high primary productivity delayed recovery from end-Permian mass extinction. Earth and Planetary Science Letters 302:278284.CrossRefGoogle Scholar
Miller, A. I., and Foote, M. 2003. Increased longevities of post-Paleozoic marine genera after mass extinctions. Science 302:10301032.CrossRefGoogle ScholarPubMed
Morten, S. D., and Twitchett, R. J. 2009. Fluctuations in the body size of marine invertebrates through the Pliensbachian-Toarcian extinction event: extinction, dwarfing and the Lilliput effect. Palaeogeography, Palaeoclimatology, Palaeoecology 284:10301032.CrossRefGoogle Scholar
Nagy, J., Hess, S., and Alve, E. 2010. Environmental significance of foraminiferal assemblages dominated by small-sized Ammodiscus and Trochammina in Triassic and Jurassic delta-influenced deposits. Earth-Science Reviews 99:3149.CrossRefGoogle Scholar
Niklas, K. J. 1994. The scaling of plant and animal body mass, length, and diameter. Evolution 48:4454.CrossRefGoogle ScholarPubMed
Norris, R. D. 1991. Biased extinction and evolutionary trends. Paleobiology 17:388399.CrossRefGoogle Scholar
Novack-Gottshall, P. M. 2008a. Ecosystem-wide body-size trends in Cambrian-Devonian marine invertebrate lineages. Paleobiology 34:210228.CrossRefGoogle Scholar
Novack-Gottshall, P. M. 2008b. Using simple body size metrics to estimate fossil body volume: empirical validation using diverse Paleozoic invertebrates. Palaios 23:163173.CrossRefGoogle Scholar
Novack-Gottshall, P. M., and Lanier, M. A. 2008. Scale-dependence of Cope's rule in body size evolution of Paleozoic brachiopods. Proceedings of the National Academy of Sciences USA 105:54305434.CrossRefGoogle ScholarPubMed
Ozaki, K., Tajima, S., and Tajika, E. 2011. Conditions required for oceanic anoxia/euxinia: constraints from a one-dimensional ocean biogeochemical cycle model. Earth and Planetary Science Letters 304:270279.CrossRefGoogle Scholar
Paine, R. T. 1976. Size-limited predation: an observational and experimental approach with the Mytilus: Pisaster interaction. Ecology 57:858873.CrossRefGoogle Scholar
Payne, J. L. 2005. Evolutionary dynamics of gastropod size across the end-Permian extinction and through the Triassic recovery interval. Paleobiology 31:269290.CrossRefGoogle Scholar
Payne, J. L., and Clapham, M. E. 2012. End-Permian extinction in the oceans: Lessons for the 21st century? Annual Review of Earth and Planetary Sciences 40:89111.CrossRefGoogle Scholar
Payne, J. L., and Finnegan, S. 2006. Controls on marine animal biomass through geological time. Geobiology 4:110.CrossRefGoogle Scholar
Payne, J. L., and Finnegan, S. 2007. The effect of geographic range on extinction risk during background and mass extinction. Proceedings of the National Academy of Sciences USA 104:1050610511.CrossRefGoogle ScholarPubMed
Payne, J. L., and van de Schootbrugge, B. 2007. Life in Triassic oceans: links between planktonic and benthic recovery and radiation. Pp. 165189inFalkowski, P. G. and Knoll, A. H., eds. Evolution of primary producers in the sea. Academic Press, Amsterdam.CrossRefGoogle Scholar
Payne, J. L., Lehrmann, D. J., Wei, J. Y., Orchard, M. J., Schrag, D. P., and Knoll, A. H. 2004. Large perturbations of the carbon cycle during recovery from the end-Permian extinction. Science 305:506509.CrossRefGoogle ScholarPubMed
Payne, J. L., Summers, M., Rego, B. L., Altiner, D., Wei, J., Yu, M., and Lehrmann, D. J. 2011. Early and Middle Triassic trends in diversity, evenness, and size of foraminifers on a carbonate platform in south China: implications for tempo and mode of biotic recovery from the end-Permian mass extinction. Paleobiology 37:409425.CrossRefGoogle Scholar
Payne, J. L., Groves, J. R., Jost, A. B., Nguyen, T., Moffitt, S. E., Hill, T. M., and Skotheim, J. M. 2012. Late Paleozoic fusulinoidean gigantism driven by atmospheric hyperoxia. Evolution (in press). doi: 10.1111/j.1558–5646.2012.01626.x.CrossRefGoogle Scholar
Peters, R. H. 1983. The ecological implications of body size. Cambridge University Press, New York.CrossRefGoogle Scholar
Pronina, G. P. 1988. The Late Permian smaller foraminifers of Transcaucasus. Revue de Paleobiologie Special Volume 2:8996.Google Scholar
Pronina-Nestell, G. P., and Nestell, M. K. 2001. Late Changhsingian foraminifers of the northwestern Caucasus. Micropaleontology 47:205234.CrossRefGoogle Scholar
R Development Core Team. 2011. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. ISBN 3-900051-07-0. http://www.R-project.org/.Google Scholar
Rettori, R. 1995. Foraminiferi del Trias inferiore e medio della Tetide: revisione tassonomica, stratigrafia ed interpretazione filogenetica. Publications du départment de géologie et paléontologie, Université de Genève 18:1149.Google Scholar
Roy, K., Jablonski, D., and Martien, K. K. 2000. Invariant size-frequency distributions along a latitudinal gradient in marine bivalves. Proceedings of the National Academy of Sciences USA 97:1315013155.CrossRefGoogle ScholarPubMed
Salaj, J., Borza, K., and Samuel, O. 1983. Triassic foraminifers of the west Carpathians. Geologický ústav Dionýza Štúra, Bratislava.Google Scholar
Schell, W. W., and Clark, D. L. 1960. Lower Triassic foraminifera from Nevada. Micropaleontology 6:291296.CrossRefGoogle Scholar
Schmidt, D. N., Thierstein, H. R., Bollmann, J., and Schiebel, R. 2004. Abiotic forcing of plankton evolution in the Cenozoic. Science 303:207210.CrossRefGoogle ScholarPubMed
Schmidt-Nielsen, K. 1984. Scaling: why is animal size so important. Cambridge University Press, New York.CrossRefGoogle Scholar
Schoene, B., Guex, J., Bartolini, A., Schaltegger, U., and Blackburn, T. J. 2010. Correlating the end-Triassic mass extinction and flood basalt volcanism at the 100 ka level. Geology 38:387390.CrossRefGoogle Scholar
Schroeder, M. L. 1968. Lower Triassic foraminifera from the Thaynes Formation in southeastern Idaho and western Wyoming. Micropaleontology 14:7382.CrossRefGoogle Scholar
Schulte, P., Alegret, L., Arenillas, I., Arz, J. A., Barton, P. J., Bown, P. R., Bralower, T. J., Christeson, G. L., Claeys, P., Cockell, C. S., Collins, G. S., Deutsch, A., Goldin, T. J., Goto, K., Grajales-Nishimura, J. M., Grieve, R. A. F., Gulick, S. P. S., Johnson, K. R., Kiessling, W., Koeberl, C., Kring, D. A., MacLeod, K. G., Matsui, T., Melosh, J., Montanari, A., Morgan, J. V., Neal, C. R., Nichols, D. J., Norris, R. D., Pierazzo, E., Ravizza, G., Rebolledo-Vieyra, M., Reimold, W. U., Robin, E., Salge, T., Speijer, R. P., Sweet, A. R., Urrutia-Fucugauchi, J., Vajda, V., Whalen, M. T., and Willumsen, P. S. 2010. The Chicxulub asteroid impact and mass extinction at the Cretaceous-Paleogene boundary. Science 327:12141218.CrossRefGoogle ScholarPubMed
Sebens, K. P. 2002. Energetic constraints, size gradients, and size limits in benthic marine invertebrates. Integrative and Comparative Biology 42:853861.CrossRefGoogle ScholarPubMed
Sepkoski, J. J. Jr., 1981. A factor analytic description of the Phanerozoic marine fossil record. Paleobiology 7:3653.CrossRefGoogle Scholar
Sheehan, P. M. 2001. The Late Ordovician mass extinction. Annual Review of Earth and Planetary Sciences 29:331364.CrossRefGoogle Scholar
Smith, A. B., and Jeffery, C. H. 1998. Selectivity of extinction among sea urchins at the end of the Cretaceous period. Nature 392:6971.CrossRefGoogle Scholar
Solé, R. V., Montoya, J. M., and Erwin, D. H. 2002. Recovery after mass extinction: evolutionary assembly in large-scale biosphere dynamics. Philosophical Transactions of the Royal Society of London B 357:697707.CrossRefGoogle ScholarPubMed
Song, H.-J., Tong, J.-N., Zhang, K.-X., Wang, Q.-X., and Chen, Z. Q. 2007. Foraminiferal survivors from the Permian-Triassic mass extinction in the Meishan section, South China. Palaeoworld 16:105119.CrossRefGoogle Scholar
Song, H., Tong, J., Chen, Z. Q., Yang, H. A. O., and Wang, Y. 2009. End-Permian mass extinction of foraminifers in the Nanpanjiang Basin, south China. Journal of Paleontology 83:718738.CrossRefGoogle Scholar
Song, H., Tong, J., and Chen, Z. Q. 2011. Evolutionary dynamics of the Permian-Triassic foraminifer size: evidence for Lilliput effect in the end-Permian mass extinction and its aftermath. Palaeogeography, Palaeoclimatology, Palaeoecology 308:98110.CrossRefGoogle Scholar
Souaya, F. J. 1976. Foraminifera of Sun-Gulf-Global Linckens Island Well P-46, Arctic Archipelago, Canada. Micropaleontology 22:249306.CrossRefGoogle Scholar
Stanley, S. M. 1973. An explanation for Cope's Rule. Evolution 27:126.CrossRefGoogle ScholarPubMed
Stanley, S. M. 1986. Population size, extinction, and speciation: the fission effect in Neogene Bivalvia. Paleobiology 12:89110.CrossRefGoogle Scholar
Stanley, S. M., and Yang, X. 1994. A double mass extinction at the end of the Paleozoic Era. Science 266:13401344.CrossRefGoogle ScholarPubMed
Thompson, D. A. W. 1942. On growth and form. University Press, Cambridge, United Kingdom.Google Scholar
Twitchett, R. J. 2001. Incompleteness of the Permian-Triassic fossil record: a consequence of productivity decline? Geological Journal 36:341353.CrossRefGoogle Scholar
Twitchett, R. J. 2007. The Lilliput effect in the aftermath of the end-Permian extinction event. Palaeogeography, Palaeoclimatology, Palaeoecology 252:132144.CrossRefGoogle Scholar
Unal, E., Altiner, D., Yilmaz, I. O., and Ozkan-Altiner, S. 2003. Cyclic sedimentation across the Permian-Triassic boundary (Central Taurides, Turkey). Rivista Italiana di Paleontologia e Stratigrafia 109:359376.Google Scholar
van de Schootbrugge, B., Payne, J. L., Tomasovych, A., Pross, J., Fiebig, J., Benbrahim, M., Föllmi, K. B., and Quan, T. M. 2008. Carbon cycle perturbation and stabilization in the wake of the Triassic-Jurassic boundary mass-extinction event. Geochemistry, Geophysics, Geosystems 9:Q04028, doi: 10.1029/2007GC001914.CrossRefGoogle Scholar
Végh-Neubrandt, E. 1982. Triassische Megalodontaceae. Akadémiai Kiadó, Budapest.Google Scholar
Vuks, V. J. 2007. Olenekian (Early Triassic) foraminifers of the Gorny Mangyshlak, eastern Precaucasus and western Caucasus. Palaeogeography, Palaeoclimatology, Palaeoecology 252:8292.CrossRefGoogle Scholar
Wegman, E. J. 1990. Hyperdimensional data analysis using parallel coordinates. Journal of the American Statistical Association 85:664675.CrossRefGoogle Scholar
Wignall, P. B. 2001. Large igneous provinces and mass extinctions. Earth-Science Reviews 53:133.CrossRefGoogle Scholar
Wignall, P. B., and Hallam, A. 1992. Anoxia as a cause of the Permian Triassic mass extinction: facies evidence from northern Italy and the western United States. Palaeogeography, Palaeoclimatology, Palaeoecology 93:2146.CrossRefGoogle Scholar
Wignall, P. B., and Hallam, A. 1993. Griesbachian (Earliest Triassic) paleoenvironmental changes in the Salt Range, Pakistan and southeast China and their bearing on the Permo-Triassic mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology 102:215237.CrossRefGoogle Scholar
Wignall, P. B., and Twitchett, R. J. 2002. Extent, duration, and nature of the Permian-Triassic superanoxic event. InKoeberl, C. and MacLeod, K. G., eds. Catastrophic events and mass extinctions: impacts and beyond. Geological Society of America Special Paper 356:395413.Google Scholar
Williford, K. H., Ward, P. D., Garrison, G. H., and Buick, R. 2007. An extended organic carbon-isotope record across the Triassic-Jurassic boundary in the Queen Charlotte Islands, British Columbia, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 244:290296.CrossRefGoogle Scholar
Xie, S., Pancost, R. D., Huang, J., Wignall, P. B., Yu, J., Tang, X., Chen, L., Huang, X., and Lai, X. 2007. Change in the global carbon cycle occurred as two episodes during the Permian-Triassic crisis. Geology 35:10831086.CrossRefGoogle Scholar
Zaninetti, L. 1976. Les foraminifères du Trias: essai de synthèse et corrélation entre les domaines mésogéens européen et asiatique. Rivista Italiana di Paleontologia 82:1258.Google Scholar