Cuvieronius

Extinct genus of mammals

Cuvieronius is an extinct New World genus of gomphothere which ranged from southern North America to western South America during the Pleistocene epoch. Among the last gomphotheres, it became extinct at the end of the Pleistocene, approximately 12,000 years ago, following the arrival of humans to the Americas.

The species now known as Cuvieronius hyodon was among the first fossil animals from the New World to be studied. The first remains of this species were recovered from Ecuador by Alexander von Humboldt, at a location the local population referred to as the "Field of Giants". Humboldt recognized that, rather than being bones of giant humans as had been thought by the local population and previous Spanish colonists, they were similar to the giant elephants (Mastodon) being described from Ohio. Humboldt sent teeth that he had collected from Mexico, Ecuador, and Chile to French anatomist Georges Cuvier, who classified the teeth into two species, which he referred to as the "mastodonte des cordilières" and the "mastodonte humboldtien", in an 1806 paper. It was not until 1824 that Cuvier formally named the species. He referred both to the genus Mastodon, calling them M. andium and M. humboldtii.

Alive, specimens typically stood about tall at the shoulder, and weighed about The skull was relatively long and low vaulted. The upper tusks were straight to slightly curved, and had a spiral shaped enamel band, and reached considerable size, with tusks in the region of in length and weights in excess of The lower tusks present in more primitive gomphotheres were vestigial in Cuvieronius, being only present in young juveniles, and the lower jaw shortened (brevirostrine). The third molars typically had 4 to 4.5 lophs/lophids, with some specimens having 5 lophs/lophids, with relatively simple crowns. In 1982, Daniel H. Janzen and Paul Schultz Martin suggested that the diet of Cuvieronius probably included fruit, and that it was likely an important seed disperser of a variety of Neotropical plants with large fleshy fruits similar to those consumed by large animals in Africa, but which lack effective living native seed dispersers, which they described as "Pleistocene anachronisms".

Cuvieronius initially evolved in North America. The oldest remains attributed to the genus from the Blancan are very fragmentary, and may belong to Rhynchotherium instead. The oldest unambiguous records of the genus in North America date to 1.4 million years ago (Ma). but persisted in southern North America (including Mexico) and Central America until the very end of the Pleistocene. During the Great American Interchange, Cuvieronius and a relative, Notiomastodon, dispersed into South America. Cuvieronius apparently reached South America considerably later than Notiomastodon, with the oldest possible date being 760,000 ±30,000 years ago and the oldest confirmed date being 304,000 ±54,000 years ago, and had a much more restricted range, confined mostly to the Andes.

In North America Cuvieronius is known from the Southern United States, including Texas, Florida, Arizona, New Mexico and Oklahoma, as well as Mexico. It was also widespread across Central America. Remains found near the town of Hockley in Texas near Austin, which date to around 24,000 years Before Present (BP), are the most recent findings north of Mexico. Cuvieronius was extirpated from South America by the end of the Late Pleistocene, with its youngest dates on the continent being around 44,000 years ago, before the arrival of people.