One of the two lineages that constitute the crown group Testudines, Pan-Pleurodira, experienced an important radiation during the Early Cretaceous, from the Barremian or earlier. The origin of the two lineages that form the crown Pleurodira (i.e. Pan-Chelidae and Pelomedusoides) is related to this radiation. Pelomedusoides diversified in northern Gondwana in a relatively short period of geological time. The African Aptian fossiliferous region of Gadoufaoua (central Niger) is one of the most interesting fossiliferous areas for the study of the early diversity and evolution of Pelomedusoides, this being where the oldest African identification of the synchronic and sympatric presence of several pleurodiran taxa is recognised. At least two lineages of Pelomedusoides are represented in Gadoufaoua, one being the extinct Araripemydidae. The second lineage had been recognised as related to Pelomedusidae or Podocnemidoidea, both clades representing part of the current biodiversity. A form from Gadoufaoua, hitherto poorly known and preliminarily presented almost 40 years ago, and currently determined as aff. Platycheloides sp., belongs to this second lineage. Its detailed study is performed here. It is defined as Francemys gadoufaouaensis gen. et sp. nov., constituting one of the few nominated pan-pleurodiran taxa (i.e., about a dozen species) currently recognised in the Lower Cretaceous record. It is identified as being closely related to Podocnemidoidea, the clade that groups the common ancestor and all of the descendants of the abundant and diverse extinct bothremydids and extant podocnemidids.
Pérez-García, A. (2019). The African Aptian Francemys gadoufaouaensis gen. et sp. nov.: New data on the early diversification of Pelomedusoides (Testudines, Pleurodira) in northern Gondwana. Cretaceous Research, 102, 112–126. https://doi.org/10.1016/j.cretres.2019.06.003