The most complete extinct species of Testudo (Testudines, Testudinidae) defined by several well-preserved skeletons from the late Miocene of Romania

Abstract

The genus Testudo was considered, for more than two centuries, to group almost all tortoises that are part of current biodiversity (i.e. the members of Testudinidae), as well as the extinct representatives of that successful lineage. However, only three extant species, as well as scarce late Miocene to late Pliocene extinct ones, are now considered attributable to that genus. The fossil record of the extinct representatives is restricted to postcranial elements. They correspond almost exclusively to shells or partial shells, most of the species being known on the basis of only one individual. Abundant material of testudinids from the late Miocene of eastern Romania (Crețești 1 fossil site, Vaslui County) is presented here. This material is attributable to Testudo, representing a new species. This find is not only relevant for the abundance of specimens, but they stand out for their unusually good preservation. Most of them are represented by partial skeletons, preserving not only several bones in anatomical connection but also some regions of the peculiar ossified dermal armour that covered their limbs. Two of these skeletons preserve the skull, which allows us to perform both the first three-dimensional reconstruction of the cranial anatomy and the first neuroanatomical study of an extinct member of Testudo. The best-preserved extinct species of the reference genus of the only extant lineage of tortoises (i.e. Testudinidae), Testudo lohanica sp. nov., is characterized in detail.