Jules D. Walter, Loredana Macaluso, Jeremy E. Martin, Thorben Grohrock, Márton Rabi, Massimo Delfino
Abstract The extinct crocodyliform Diplocynodon represents one of the best sampled tetrapods of the Cenozoic era. Endemic to Europe, the fossil record of the taxon spans from the upper Paleocene to the Middle Miocene, documented by a vast number of occurrences comprising both exceptionally well‐preserved and fragmentary material. The clade is considered to have reached a peak of diversity during the Eocene, implying allopatric or possibly even sympatric lineage divergence. Based on a critical review and first‐hand examination of Diplocynodon species, we present the first comprehensive taxonomic revision of the group since its inclusion in modern phylogenetic works. We hereby demonstrate that the diagnoses of several species often include shared and/or irreproducible characters, hampering specific delimitation. This taxonomic revision of Diplocynodon spp. presents amended diagnoses for the genus and the species, and confirms 9 valid taxa out of the 11 previously published, recognizing two additional species among an updated list of dubious species. Furthermore, we quantitatively and qualitatively review the state of the published fossil record of Diplocynodon , based on two openly available databases, and comment on the state of the art of the taxon record with respect to recommended taxonomic practices.