Ephelcomenus

Ephelcomenus is an extinct genus of Palaeogene artiodactyls belonging to the Anoplotheriidae that were endemic to Western Europe. It contains one species E. filholi, which was first described by Richard Lydekker in 1889 but eventually classified to its own genus by the Swiss palaeontologist Johannes Hürzeler in 1938. It has an uncertain stratigraphic range, but some sources suggest that it was present in the Oligocene after the Grande Coupure turnover event of western Europe.

Ephelconemus has several unusual traits compared to other anoplotheriids, such as an elongated and tusk-shaped first upper incisor and a hollow first phalanx. The latter trait, along with the typical flexible limb morphologies of anoplotheriids, led Hürzeler to hypothesize that it was specialized for fossorial behaviors, meaning that it may have burrowed and eaten grounded plant material. The hypothesis has not been tested, but other members of the subfamily Anoplotheriinae such as Anoplotherium and Diplobune are also suggested to have unusual adaptations as well. It was larger in size compared to other anoplotheriines except for Anoplotherium and most species of Diplobune and likely inhabited forested environments.

Taxonomy

In 1938, Swiss palaeontologist Johannes Hürzeler wrote about an artiodactyl that he observed was from the middle Stampien (= Rupelian). He reviewed species classified to the anoplotheriid genus Hyracodontherium, previously erected by Henri Filhol in 1877. Among them, he stated that the type species H. primaevum belonged to the genus Diplobune, effectively making Hyracodontherium a synonym of Diplobune.