Abstract
BackgroundAmphibians, due to their ecophysiological peculiarities, have a physiology dependent on environmental conditions and sensitively respond to their changes. Here, the oldest record of the genus Thaumastosaurus is described, whose fossil record known exclusively from Western Europe is discussed in the scope of the climatic changes of 33.5–40.5 Ma.ResultsIn the present paper, the fossil remains of the genus from three localities in Switzerland (11 samples overall) have been studied and referred to the species Thaumastosaurus bottii. Its stratigraphic distribution has been revised and summarised. The studied localities present the stratigraphically oldest and the most eastern occurrences of the genus Thaumastosaurus. Eocene probable ranids (Ranidae indet./Rana sp./? Rana sp.) from Europe could be referred to Thaumastosaurus.DiscussionTheir first occurrence of ranids most likely coincides with a warm phase of the global climate at 40 Ma, as tropical conditions were prevailing in Europe. As a result of the gradual cooling of the global climate, the tropical conditions in Europe were replaced by drier open habitats towards the latest Eocene at 34 Ma, when the latest occurrence of the European endemic genus Thaumastosaurus is known. Taking the fossil record and the climate evolution of that time into account, it can be concluded that Thaumastosaurus represents one of the groups among the vertebrates that disappeared during the large extinction event at the Eo–Oligocene transition, known as the Grande Coupure. The fossil finds of the genus from the studied localities allow to refer the previously suggested Eocene true frogs to the genus Thaumastosaurus, hereby stating the arrival of the true frog family Ranidae by the genus Pelophylax in Europe from the east at the earliest Oligocene.
Highlights
Climate changes strongly shape the spatial distribution and diversity of animals (Winter et al, 2016)
During the late middle–late Eocene (MP16–20), anuran fauna in Europe were represented by several clades: Alytidae, Pelodytidae, Pelobatidae, ?Ranidae
Rana sp./Ranidae indet. and the European endemic genus Thaumastosaurus co-occur in the stratigraphic record
Summary
Climate changes strongly shape the spatial distribution and diversity of animals (Winter et al, 2016). In the terminal Eocene, the genus Thaumastosaurus disappeared at the ‘‘Grand Coupure’’ event (Rage, 2012) (Fig. 1A; Table S1), when all herpetofauna (mammalian as well) declined and were gradually replaced by fewer fauna These changes are best documented for the amphibian and reptile fauna of the Quercy region (Rage, 2012) (Fig. 1C). As a result of the gradual cooling of the global climate, the tropical conditions in Europe were replaced by drier open habitats towards the latest Eocene at 34 Ma, when the latest occurrence of the European endemic genus Thaumastosaurus is known. The fossil finds of the genus from the studied localities allow to refer the previously suggested Eocene true frogs to the genus Thaumastosaurus, hereby stating the arrival of the true frog family Ranidae by the genus Pelophylax in Europe from the east at the earliest Oligocene
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
