Dentaneosuchus is a genus of large bodied sebecid crocodylomorph from the Middle Eocene of Issel and Réalmont (France). Originally described as Atacisaurus crassiproratus, the discovery of additional remains led to it being placed in a separate genus in 2023. It was tentatively recovered as the basalmost member of the family Sebecidae. Because of this Dentaneosuchus could play an important part in deciphering the origins and dispersal of European sebecids, as their presence on the continent, far away from their primary range in South America, is still not entirely resolved. It reached a similar size to the enormous Barinasuchus, making it not only one of the biggest sebecids but also the biggest terrestrial carnivore of Cenozoic Europe. Dentaneosuchus would have been an apex predator of its environment, capable of taking large prey such as Lophiodon. However, for as of yet unknown reasons crocodylomorphs would lose their spot as top predator in this part of the world by the end of the Eocene, with Dentaneosuchus representing one of the last members of its group in Europe.
History and naming
The first fossil of Dentaneosuchus, a mandibular symphysis catalogued as specimen MHNT.PAL.2006.0.53., was discovered in the Sables du Castrais Formation near Issel in southern France and assigned to the genus Atacisaurus by Gaston Astre in 1931, creating the name Atacisaurus crassiproratus. When describing Iberosuchus in 1975, Miguel Telles Antunes considered the possibility that the Issel remains may have belonged to the same animal, tentatively referring the symphysis to his new genus, and Ortega et al. (1996) agreed with this placement.
In 2018 Godinot and colleagues went as far as to fully place the specimen in Iberosuchus while retaining the species name, creating the new combination Iberosuchus crassiproratus. However, the referral of various European sebecid specimens to Iberosuchus was at times done under less than ideal conditions, as much of the material didn't overlap and the assignment was in large parts based on very few characters not exclusive to the genus. Excavations in France meanwhile continued to yield sebecid material, including specimens discovered in 1997 near Réalmont. It is possible that this specimen was a once nearly complete skull, however, it was damaged during the dig, with much associated material being gathered from the surrounding debris. Despite this a lot of material could be gathered regardless, which remain in the collection of the Muséum de Toulouse until the fossils were studied by Martin and colleagues.
Martin et al. compared the Réalmont material with both Iberosuchus and the Issel symphysis, determining that there were no differences between the mandibular remains from the two localities yet clear deviations from Iberosuchus macrodon. As the Issel material had been validly described and diagnosed in 1931, the species name could be retained, however the matter of the genus name was more complicated. When naming Atacisaurus, Astre declared A. glarea the type species, but in the following years the holotype had been lost and available figures failed to show any diagnostic traits. Material previously assigned to Atacisaurus glarea meanwhile was initially considered to serve as a lectotype, but lacked shared features with the lost material and was instead found to have belonged to a gavialoid then named Kentisuchus astrei. This rendered Atacisaurus a nomen dubium, leading Martin and colleagues to coin a new genus name for A. crassiproratus, Dentaneosuchus.
The name Dentaneosuchus derives from the Latin "dentaneo", which roughly translates to "showing teeth" or "fightfull" in allusion to its hypothesized role as apex predator, and the Greek "souchos" meaning crocodile, derived from the name of the Egyption deity Sobek.