Large freshwater plesiosaurian from the Cretaceous (Aptian) of Australia
2013; Taylor & Francis; Volume: 37; Issue: 4 Linguagem: Inglês
10.1080/03115518.2013.772825
ISSN1752-0754
AutoresRoger Benson, Erich M. G. Fitzgerald, Thomas H. Rich, Patricia Vickers-Rich,
Tópico(s)Evolution and Paleontology Studies
ResumoAbstractBenson, R.B.J., Fitzgerald, E.M.G., Rich, T.H. & Vickers-Rich, P., 2013. Large freshwater plesiosaurian from the Cretaceous (Aptian) of Australia. Alcheringa 37, 1–6. ISSN 0311-5518We report a large plesiosaurian tooth from the freshwater early–middle Aptian (Early Cretaceous) Eumeralla Formation of Victoria, Australia. This, combined with records of smaller plesiosaurian teeth with an alternative morphology, provides evidence for a multitaxic freshwater plesiosaurian assemblage. Dental and body size differences suggest ecological partitioning of sympatric freshwater plesiosaurians analogous to that in modern freshwater odontocete cetaceans. The evolutionarily plastic body plan of Plesiosauria may have facilitated niche differentiation and helped them to exclude ichthyosaurs from freshwater environments during the Mesozoic. However, confirmation of this hypothesis requires the discovery of more complete remains.Roger B.J. Benson [roger.benson@earth.ox.ac.uk], Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK; Erich M.G. Fitzgerald [efitzgerald@museum.vic.gov.au], Thomas H. Rich [trich@museum.vic.gov.au], Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia; Thomas H. Rich and Patricia Vickers-Rich [pat.rich@monash.edu], School of Geosciences, Monash University, Clayton, Victoria 3800, Australia. Received 30.10.2012; revised 27.1.2013; accepted 31.1.2013.澳大利亚白垩纪 (Aptian) 大型淡水蛇颈龙我们在此报道澳大利亚维多利亚早至中Aptian阶 (早白垩世) Eumeralla组淡水中的一个大蛇颈龙牙齿。与较小的不同形态的蛇颈龙牙齿的记录一起, 它提供了证据来证实多种类型淡水蛇颈龙组合。牙齿特征和身体大小的差异说明同域淡水蛇颈龙的生态隔离, 这和现代淡水齿鲸类鲸鱼的生态隔离类似。从演化角度来说, 蛇颈龙的塑性身体平面也许造成了它们的生境分异, 并有助于中生代期间将鱼龙挤出淡水环境。然而, 证实这个假说还需要发现更完整的化石。Key words: freshwater plesiosaursPlesiosauriaCretaceousEumeralla FormationVictoria AcknowledgementsWe thank M. Cleeland for his discovery of NMV P198945; L. Kool for fossil preparation; and D. Pickering for access to collections at Museum Victoria. R.B.J.B. was funded by a Research Project Grant from the Leverhulme Foundation (RPG-129) awarded to Paul Upchurch. E.M.G.F. is supported by the Harold Mitchell Foundation and Museum Victoria. Substantial sampling of the Victorian Cretaceous fauna would not have occurred without support from National Geographic, Atlas Copco, the Australian Research Council (ARC), Monash University, Museum Victoria, and the dedication of numerous volunteers, collectors and other individuals.
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