Fossilium Catalogus I: Animalia Pars 149 - Hans-Volker Karl

The turtles are one of the most long-lasting groups of tetrapods. They are documented from their earliest record of Lower Triassic (Skythian) age until today which means a period of time of approximately 250 million years, leading to a large number of different systematic groups. Their diversity shows distinct and significant cuts at the Triassic/Jurassic (= Keuper/Liassic), Albian/Cenomanian, Cretaceous/Paleogene, Paleogene/Neogene and Neogene/Pleistocene boundaries. The most ancient turtle fauna disappears almost completely at the end of the Triassic, the younger turtle fauna begins sparsely in the Lower Jurassic (Liassic) and extends to the Cretaceous/Paleogene boundary and represents the first period of prosperity. The older turtles are now commonly grouped together as “basal turtles” which is not a taxonomically valid term. So far, the traces of their activity were not taken into account explicitly or were mentioned only scarcely and out of context. Even in recent years this is in particular true for the Triassic turtles, but in fact their fossil traces are important because they are the only connections with the Permian ancestors of the turtles. Therefore the aim of the present article is a documentation of the current state of knowledge of the connections between Permotriassic morphotaxa of turtles and tortoises and their traces like tracks (= ichnofossils) and fossil eggs. Odontochelys mediates between the Permian Eunotosaurus and the Triassic turtle-like taxa as summarized under the Testudinomorpha (figure 1). The name Chelonomorpha is preoccupied. These animals have their decisive radiation from the Permian to the Triassic.