An exceptionally complete specimen of the colossal Cretaceous sea turtle Archelon ischyros
2011 (English)In: 9th Annual Meeting of the European Association of Vertebrate Palaeontologists, 2011, 48- p.Conference paper (Other academic)
Remains of Cretaceous sea turtles (Chelonioidea) are widespread with exemplars known from North and South America, Europe, North Africa, eastern Asia, and the Australasian region. Although members of the modern cheloniid and dermochelyid lineages were present by at least the Coniacian (Late Cretaceous), by far the most diverse group were the protostegids − a basal radiation that first appeared during the Aptian-Albian but went extinct by the early-middle Maastrichtian. Probably the most iconic protostegid is Archelon ischyros from the Campanian Pierre Shale of western North America (Western Interior Seaway), which is famous for its colossal body length of over 4 m and has been popularised as the largest turtle of all time. Surprisingly, little research has been devoted to Archelon since the taxon was first described in the late 19th Century. Several variably complete skeletons have been collected, the most spectacular of which was unearthed in South Dakota during the mid 1970’s and eventually purchased by the Natural History Museum of Vienna. Painstaking preparation over a five year period revealed exceptional preservation and the specimen now forms the centerpiece of a permanent exhibition of Mesozoic fossils. However, despite being on public display for over 30 years the fossil has never been studied in detail. A comprehensive assessment undertaken in 2011 obtained novel data on the osteology, diet, and evolutionary implications of Archelon. The results suggest some remarkable parallels with modern sea turtles, including durophagous habits and possibly advanced thermal physiology (indicated by flipper morphology and highly vascularised limb bones). Contrary to some recent phylogenies our cladistic analyses also clearly advocate chelonioid monophyly and imply that the decline of protostegids might have been linked to faunal turnover amongst benthic invertebrate prey species and extreme specialisation towards regionally endemic habitats.
Place, publisher, year, edition, pages
2011. 48- p.
Other Earth and Related Environmental Sciences
Research subject Earth Science with specialization in Historical Geology and Palaeontology
IdentifiersURN: urn:nbn:se:uu:diva-166628OAI: oai:DiVA.org:uu-166628DiVA: diva2:476983
9th Annual Meeting of the European Association of Vertebrate Palaeontologists,