Choeropotamus

Choeropotamus is an extinct genus of Palaeogene artiodactyls and the type genus of the family Choeropotamidae. It was endemic to western Europe and lived from the Middle Eocene up to the earliest Oligocene. Choeropotamus was first described and named in 1822 by the French naturalist George Cuvier, who noted its distinct morphology from other contemporary fossil artiodactyls. Cuvier reused the name Choeropotamus from its use by 17th century Venetian physician Prospero Alpini, who previously used it to describe stuffed hippopotamuses that he incorrectly thought to be distinct species. There are currently five described species of Choeropotamus, with C. parisiensis being the type species.

Choeropotamus had an broad and low, yet elongated skull, with a similarly elongated but narrow mandible. Its cheek teeth generally possess diastemata (or gaps) in between them. Although mostly known from dental fossils and mostly lacking in postcranial evidence, its skull anatomy and evolutionary history have both been well-recorded, with sufficient evidence of the five species forming a progressive lineage that gained cusps in the molars and increased in size; from the earliest and smallest C. lautricensis to the latest-appearing and largest C. parisiensis, which may have weighed about 58.8 kg (130 lb), sizable compared to many contemporary artiodactyls. The bunodont (round-cusped) molars of Choeropotamus point towards either a frugivorous or omnivorous diet, in which it could have occasionally consumed meat.

During the time that Choeropotamus was extant, western Europe was an archipelago with a tropical-subtropical climate that was isolated from the rest of Eurasia, living alongside various other animals which were also highly endemic. It went extinct by the Grande Coupure extinction/faunal turnover event, coinciding with shifts towards further glaciation and seasonality plus dispersals of Asian immigrant faunas into western Europe. However, the specific causes of Choeropotamus' extinction are unclear.