Spoochelys ormondea gen. et sp. nov., an ArchaicMeiolaniid-Like Turtle from the Early Cretaceousof Lightning Ridge, Australia
2012 (English)In: Morphology and Evolution of Turtles / [ed] Donald B. Brinkman, Patricia A. Holroyd, James D. Gardener, Dordrecht: Springer, 2012, 1, 121-146 p.Chapter in book (Refereed)
The Lower Cretaceous (lower to middle Albian)Griman Creek Formation deposits of Lightning Ridge incentral-eastern Australia are famous for producing opalisedfossils. Much of this material is poorly documented butrecent assessments suggest a diverse assemblage of mainlynon-marine vertebrates, invertebrates and plants. This biotais associated with a Gondwanan high-latitude zone thatwould have been subject to cool-temperate conditions.Turtle remains are particularly common at Lightning Ridge,comprising several distinct lineages including aquaticchelids and peculiar meiolaniid-like taxa—meiolaniidswere spectacular horned turtles known from the Australianregion and South America. Spoochelys ormondea gen. et sp.nov. shares some distinctive skeletal traits with this group(e.g., cranial scute pattern, incisura columellae aurisconfluent with the Eustachian tube) but also retainsremarkably plesiomorphic cranial structures (e.g., an interpterygoidvacuity and short inferior parietal process) thatare otherwise characteristic of Triassic and Jurassic stemturtles. The placement of meiolaniids and their sisterlineages within Testudines is controversial in recent phylogenies.To test the relationships of Spoochelys, we usedthe two most comprehensive published data sets of fossilTestudinata and rescored a number of characters. SeparateMaximum Parsimony and Bayesian analyses of bothmatrices supported recognition of Spoochelys as a primitivetestudinatan but could not confirm its relationships with the meiolaniid clade. Nevertheless, the persistence ofsurprisingly archaic taxa such as Spoochelys into the EarlyCretaceous of Australia implies survival of an ancientPangean lineage, and brings into question long-heldassumptions of Laurasian affinities for the meiolaniid-liketurtles of Gondwana.
Place, publisher, year, edition, pages
Dordrecht: Springer, 2012, 1. 121-146 p.
Albian, Gondwana, high-palaeolatitude, Meiolaniidae, terrestrial, relict taxon
Other Earth and Related Environmental Sciences
Research subject Earth Science with specialization in Historical Geology and Palaeontology
IdentifiersURN: urn:nbn:se:uu:diva-184852DOI: 10.1007/978-94-007-4309-0ISBN: 978-94-007-4308-3OAI: oai:DiVA.org:uu-184852DiVA: diva2:568070