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Completeness metrics and the quality of the sauropodomorph fossil record through geological and historical time

Published online by Cambridge University Press:  08 April 2016

Philip D. Mannion
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom. E-mail: p.mannion@ucl.ac.uk
Paul Upchurch
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom. E-mail: p.upchurch@ucl.ac.uk

Abstract

Despite increasing concerns about the effect of sampling biases on our reading of the fossil record, few studies have considered the completeness of the fossil remains themselves, and those that have tend to apply non-quantitative measures of preservation quality. Here we outline two new types of metric for quantifying the completeness of the fossil remains of taxa through time, using sauropodomorph dinosaurs as a case study. The “Skeletal Completeness Metric” divides the skeleton up into percentages based on the amount of bone for each region, whereas the “Character Completeness Metric” is based on the number of characters that can be scored for each skeletal element in phylogenetic analyses. For both metrics we calculated the completeness of the most complete individual and of the type specimen. We also calculated how well the taxon as a whole is known from its remains. We then plotted these results against both geological and historical time, and compared curves of the former with fluctuations in sauropodomorph diversity, sea level, and sedimentary rock outcrop area. Completeness through the Mesozoic shows a number of peaks and troughs; the Early Jurassic (Hettangian–Sinemurian) is the interval with highest completeness, whereas the mid-to-Late Cretaceous has completeness levels that are consistently lower than the rest of the Mesozoic. Completeness shows no relationship to rock outcrop area, but it is negatively correlated with sea level during the Jurassic–Early Cretaceous and correlated with diversity in the Cretaceous. Completeness of sauropodomorph type specimens has improved from 1830 to the present, supporting the conclusions of other recent studies. However, when this time interval is partitioned, we find no trend for an increase in completeness from the 1990s onward. Moreover, the 2000s represent one of the poorest decades in terms of average type specimen completeness. These results highlight the need for quantitative methods when assessing fossil record quality through geological time or when drawing conclusions about historical trends in the completeness of taxa. The new metrics may also prove useful as sampling proxies in diversity studies.

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Articles
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Copyright © The Paleontological Society 

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References

Literature Cited

Alroy, J., Aberhan, M., Bottjer, D. J., Foote, M., Fürsich, F. T., Harries, P. J., Hendy, A. J. W., Holland, S. M., Ivany, L. C., Kiessling, W., Kosnik, M. A., Marshall, C. R., McGowan, A. J., Miller, A. I., Olszewski, T. D., Patzkowsky, M. E., Peters, S. E., Villier, L., Wagner, P. J., Bonuso, N., Borkow, P. S., Brenneis, B., Clapham, M. E., Fall, L. M., Ferguson, C. A., Hanson, V. L., Krug, A. Z., Layou, K. M., Leckey, E. H., Nürnberg, S., Powers, C. M., Sessa, J. A., Simpson, C., Tomašových, A., and Visaggi, C. C. 2008. Phanerozoic trends in the global diversity of marine invertebrates. Science 321:97100.Google Scholar
Apesteguía, S. 2007. The sauropod diversity of the La Amarga Formation (Barremian), Neuquén (Argentina). Gondwana Research 12:533546.Google Scholar
Badgley, C. E. 1986. Counting individuals in mammalian fossil assemblages from fluvial environments. Palaios 1:328338.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 as illustrated by the fossil record. Elsevier, Amsterdam.CrossRefGoogle Scholar
Barrett, P. M., McGowan, A. J., and Page, V. 2009. Dinosaur diversity and the rock record. Proceedings of the Royal Society of London B 276:26672674.Google ScholarPubMed
Behrensmeyer, A. K., Kidwell, S. M., and Gastaldo, R. A. 2000. Taphonomy and paleobiology. Paleobiology 26:103144.CrossRefGoogle Scholar
Benton, M. J. 2008a. Fossil quality and naming dinosaurs. Biology Letters 4:729732.Google Scholar
Benton, M. J. 2008b. How to find a dinosaur, and the role of synonymy in biodiversity studies. Paleobiology 34:516533.Google Scholar
Benton, M. J., Wills, M. A., and Hitchin, R. 2000. Quality of the fossil record through time. Nature 403:534537.CrossRefGoogle ScholarPubMed
Bonaparte, J. F. 1986. The early radiation and phylogenetic relationships of the Jurassic sauropod dinosaurs, based on vertebral anatomy. Pp. 247258 in Padian, K., ed.Google Scholar
Butler, R. J., Barrett, P. M., Nowbath, S., and Upchurch, P. 2009. Estimating the effects of sampling biases on pterosaur diversity patterns: implications for hypotheses of bird/pterosaur competitive replacement. Paleobiology 35:432446.Google Scholar
Calvo, J. O., and Salgado, L. 1995. Rebbachisaurus tessonei sp. nov. a new Sauropoda from the Albian-Cenomanian of Argentina; new evidence on the origin of the Diplodocidae. GAIA 11:1333.Google Scholar
Calvo, J. O., Porfiri, J. D., González-Riga, B. J., and Kellner, A. W. A. 2007. A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur. Anais da Academia Brasileira de Ciências 79:529541.CrossRefGoogle ScholarPubMed
Carrano, M. T. 2008. Taxonomy and classification of non-avian Dinosauria. Paleobiology Database Online Systematics Archive 4 (www.paleodb.org).Google Scholar
Carrano, M. T., and Sampson, S. D. 2008. The phylogeny of Ceratosauria (Dinosauria: Theropoda). Journal of Systematic Palaeontology 6:183236.Google Scholar
Crampton, J. S., Beu, A. G., Cooper, R. A., Jones, C. M., Marshall, B., and Maxwell, P. A. 2003. Estimating the rock volume bias in paleobiodiversity studies. Science 301:358360.Google Scholar
Rogers, K. A. Curry 2005. Titanosauria: a phylogenetic overview. Pp. 50103 in Rogers, K. A. Curry and Wilson, J. A., eds. 2005. The sauropods: evolution and paleobiology. University of California Press, Berkeley.Google Scholar
Rogers, K. A. Curry, and Forster, C. A. 2001. The last of the dinosaur titans: a new sauropod from Madagascar. Nature 412:530534.CrossRefGoogle Scholar
Davis, J. C. 1986. Statistics and data analysis in geology. Wiley, Chichester, U.K. Google Scholar
Fountaine, T. M. R., Benton, M. J., Nudds, R. L., and Dyke, G. J. 2005. The quality of the fossil record of Mesozoic birds. Proceedings of the Royal Society of London B 272:289294.Google Scholar
Galton, P. M., and Upchurch, P. 2004. Prosauropoda. Pp. 232258 in Weishampel, et al., 2004b.CrossRefGoogle Scholar
Gilinsky, N. L., and Bennington, J. B. 1994. Estimating numbers of whole individuals from collections of body parts: a taphonomic limitation of the paleontological record. Paleobiology 20:245258.Google Scholar
Hammer, Ø., and Harper, D. A. T. 2006. Paleontological data analysis. Blackwell, Oxford.Google Scholar
Hammer, Ø., Harper, D. A. T., and Ryan, P. D. 2001. PAST: paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4:9.Google Scholar
Haq, B., Hardenbol, J., and Vail, P. 1987. Chronology of fluctuating sea levels since the Triassic. Science 235:11561167.CrossRefGoogle ScholarPubMed
Huene, F. v. 1929. Los saurisquios y ornithisquios del Cretáceo Argentino. Annales del Museo de La Plata 3:1196.Google Scholar
Hunt, A. P., Lockley, M. G., Lucas, S. G., and Meyer, C. A. 1994. The global sauropod fossil record. GAIA 10:261279.Google Scholar
Leanza, H. A., and Hugo, C. A. 2001. Cretaceous red beds from southern Neuquén Basin (Argentina): age, distribution and stratigraphic discontinuities. In Leanza, H. A., ed. Proceedings of the VII international symposium on Mesozoic terrestrial ecosystems. Asociación Paleontólogica Argentina Publicación Especial 7:117122.Google Scholar
Mannion, P. D. 2008. Environmental associations of sauropod dinosaurs and their bearing on the early Late Cretaceous “sauropod hiatus.” Journal of Vertebrate Paleontology 28(Suppl. to No. 3):111.Google Scholar
Mannion, P. D. 2010. A revision of the sauropod dinosaur genus ‘Bothriospondylus’ with a redescription of the type material of the Middle Jurassic form ‘B. madagascariensis.’ Palaeontology (in press).Google Scholar
Mannion, P. D., and Upchurch, P. 2010. A quantitative analysis of environmental associations in sauropod dinosaurs. Paleobiology 36:253282 [this volume].CrossRefGoogle Scholar
Markwick, P. J. 1998. Fossil crocodilians as indicators of Late Cretaceous and Cenozoic climates: implications for using palaeontological data in reconstructing palaeoclimate. Palaeogeography, Palaeoclimatology, Palaeoecology 137:205271.Google Scholar
Monbaron, M., Russell, D. A., and Taquet, P. 1999. Atlasaurus imelakeii n.g., n.sp., a brachiosaurid-like sauropod from the Middle Jurassic of Morocco. Comptes Rendus de l'Académie des Sciences (Science de la Terre and des Planètes) 329:519526.Google Scholar
Moore, J. R., Norman, D. B., and Upchurch, P. 2007. Assessing relative abundances in fossil assemblages. Palaeogeography, Palaeoclimatology, Palaeoecology 253:317322.CrossRefGoogle Scholar
Naish, D., and Martill, D. M. 2007. Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: basal Dinosauria and Saurischia. Journal of the Geological Society, London 164:493510.CrossRefGoogle Scholar
Ogier, A. 1975. Étude de nouveaux ossements de Bothriospondylus (Sauropode) d'un gisement du Bathonien de Madagascar. . Université de Paris, Paris.Google Scholar
Peters, S. E. 2005. Geological constraints on the macroevolutionary history of marine animals. Proceedings of the National Academy of Sciences USA 102:1232612331.Google Scholar
Peters, S. E. 2008. Environmental determinants of extinction selectivity in the fossil record. Nature 454:626629.Google Scholar
Peters, S. E., and Foote, M. 2002. Determinants of extinction in the fossil record. Nature 416:420424.CrossRefGoogle ScholarPubMed
Pol, D., and Norell, M. A. 2006. Uncertainty in the age of fossils and the stratigraphic fit to phylogenies. Systematic Biology 55:512521.Google Scholar
Raup, D. M. 1972. Taxonomic diversity during the Phanerozoic. Science 177:10651071.Google Scholar
Raup, D. M. 1975. Taxonomic diversity estimation using rarefaction. Paleobiology 1:333342.Google Scholar
Rice, W. R. 1989. Analyzing tables of statistical tests. Evolution 43:223225.CrossRefGoogle ScholarPubMed
Salgado, L., and Carvalho, I. S. 2008. Uberabatitan ribeiroi, a new titanosaur from the Marília Formation (Bauru Group, Upper Cretaceous), Minas Gerais, Brazil. Palaeontology 51:881901.Google Scholar
Salgado, L., Coria, R. A., and Calvo, J. O. 1997. Evolution of titanosaurid sauropods. I. Phylogenetic analysis based on the postcranial evidence. Ameghiniana 34:332.Google Scholar
Smith, A. B. 1994. Systematics and the fossil record. Blackwell Scientific, Oxford.Google Scholar
Smith, A. B. 2007. Intrinsic versus extrinsic biases in the fossil record: contrasting the fossil record of echinoids in the Triassic and early Jurassic using sampling data, phylogenetic analysis, and molecular clocks. Paleobiology 33:310323.CrossRefGoogle Scholar
Smith, A. B., and McGowan, A. J. 2007. The shape of the Phanerozoic marine palaeodiversity curve: how much can be predicted from the sedimentary rock record of Western Europe? Palaeontology 50:765774.Google Scholar
Taylor, M. P., and Naish, D. 2007. An unusual new neosauropod dinosaur from the Lower Cretaceous Hastings Beds Group of East Sussex, England. Palaeontology 50:15471564.Google Scholar
Upchurch, P. 1995. Evolutionary history of sauropod dinosaurs. Philosophical Transactions of the Royal Society of London B 349:365390.Google Scholar
Upchurch, P. 1998. The phylogenetic relationships of sauropod dinosaurs. Zoological Journal of the Linnaean Society 124:43103.Google Scholar
Upchurch, P., and Barrett, P. M. 2005. A phylogenetic perspective on sauropod diversity. Pp. 104124 in Rogers, K. A. Curry and Wilson, J. A., eds. 2005. The sauropods: evolution and paleobiology. University of California Press, Berkeley.Google Scholar
Upchurch, P., Barrett, P. M., and Dodson, P. 2004a. Sauropoda. Pp. 259322 in Weishampel, et al., 2004b.Google Scholar
Upchurch, P., Tomida, Y., and Barrett, P. M. 2004b. A new specimen of Apatosaurus ajax (Sauropoda: Diplodocidae) from the Morrison Formation (Upper Jurassic) of Wyoming, USA. National Science Museum Monographs 26:1108.Google Scholar
Upchurch, P., Barrett, P. M., and Galton, P. M. 2007a. The phylogenetic relationships of basal sauropodomorphs: implications for the origin of sauropods. In Barrett, P. M. and Batten, D. J., eds. Evolution and paleobiology of early sauropodomorph dinosaurs. Special Papers in Palaeontology 77:5790.Google Scholar
Upchurch, P., Barrett, P. M., Zhao, X., and Xu, X. 2007b. A reevaluation of Chinshakiangosaurus chunghoensis Ye vide Dong 1992 (Dinosauria, Sauropodomorpha): implications for cranial evolution in basal sauropod dinosaurs. Geological Magazine 144:116.Google Scholar
Waite, S. 2000. Statistical ecology in practice: a guide to analysing environmental and ecological field data. Pearson Education Limited, Harlow, U.K. Google Scholar
Weishampel, D. B., Barrett, P. M., Coria, R. E., Le Loeuff, J., Gomani, E. S., Zhao, Z., Xu, X., Sahni, A., and Noto, C. 2004a. Dinosaur distribution. Pp. 517606 in Weishampel, et al., 2004b.Google Scholar
Weishampel, D. Dodson, B. P., and Osmólska, H. 2004b. The Dinosauria, 2d ed. University of California Press, Berkeley.Google Scholar
Wills, M. A. 2007. Fossil ghost ranges are most common in some of the oldest and some of the youngest strata. Proceedings of the Royal Society of London B 274:24212427.Google Scholar
Wills, M. A., Barrett, P. M., and Heathcote, J. F. 2008. The Modified Gap Excess Ratio (GER) and the stratigraphic congruence of dinosaur phylogenies. Systematic Biology 57:891904.Google Scholar
Wilson, J. A. 2002. Sauropod dinosaur phylogeny: critique and cladistic analysis. Zoological Journal of the Linnaean Society 136:217276.Google Scholar
Wilson, J. A., and Sereno, P. C. 1998. Early evolution and higher-level phylogeny of the sauropod dinosaurs. Society of Vertebrate Paleontology Memoir 5. Journal of Vertebrate Paleontology 18(Suppl.):168.CrossRefGoogle Scholar
Wilson, J. A., and Upchurch, P. 2003. A revision of Titanosaurus (Dinosauria Sauropoda), the first ‘Gondwanan’ dinosaur genus. Journal of Systematic Palaeontology 1:125160.Google Scholar
Wilson, J. A., and Upchurch, P. 2009. Redescription and reassessment of the phylogenetic affinities of Euhelopus zdanskyi (Dinosauria: Sauropoda) from the Late Jurassic or Early Cretaceous of China. Journal of Systematic Palaeontology 7:199239.Google Scholar
Wiman, C. 1929. Die Kreide-Dinosaurier aus Shantung. Palaeontologia Sinica C 6:167.Google Scholar
Xu, X., Zhang, X., Tan, Q., Zhao, X., and Tan, L. 2006. A new titanosaurian sauropod from Late Cretaceous of Nei Mongol, China. Acta Geologica Sinica 80:2026.Google Scholar
Yates, A. M. 2007. The first complete skull of the Triassic dinosaur Melanorosaurus Haughton (Sauropodomorpha: Anchisauria). In Barrett, P. M., and Batten, D. J., eds. Evolution and paleobiology of early sauropodomorph dinosaurs. Special Papers in Palaeontology 77:955 Google Scholar
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