Cuvieronius

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. A 2026 study suggested reviving C. tropicus however. == Description ==

Alive, specimens typically stood about tall at the shoulder, and weighed about , making it around the same size as an Asian elephant. 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. ==Evolution==

Cuvieronius initially evolved in North America. while other authors suggest the earliest unambiguous appearance of Cuvieronius in the fossil record in North America dates to somewhat later, around 1.4 million years ago (Ma). 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 to the northern Andes. == Distribution and habitat ==

Cuvieronius inhabited tropical and subtropical latitudes, in environments spanning from savanna and grassland in northern Mexico, open gallery forest in Guatemala, tropical rainforest in Costa Rica, It spanned altitudes from below current sea level on the continental shelf (but which during the Pleistocene was periodically exposed as dry land) near the Pearl Islands of what is now Panama, In North America, Cuvieronius is known from the southern and southwestern United States with remains reported (spanning from the Early Pleistocene to Late Pleistocene) from North & South Carolina, Texas, Florida, Arizona, New Mexico and Oklahoma, as well as across Mexico. Fossils of Cuvieronius are widespread across Central America. By the Late Pleistocene it had become considerably rarer and/or locally extinct/extirpated across much of the northern part of its North American range, and remains found near the town of Hockley in Texas near Houston, which date to around 24,000 years Before Present (BP), are the most recent findings north of Mexico. Many gomphothere remains in South America historically referred to Cuvieronius actually refer to Notiomastodon, with many previous studies simply labeling fossils one or the other depending on location. Considering only localities definitely identified as Cuvieronius, the range of Cuvieronius in South America is now considered to span the high Andes from Ecuador in the north, to Bolivia in the south, with the localities in the southern Andes in Chile and Argentina now thought to belong to Notiomastodon. == Ecology ==

Cuvieronius is suggested to have been a generalist mixed feeder that consumed a wide range of plant resources, including grasses and browse (the leaves and twigs of plants like trees and shrubs). 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". Cuvierionius may have lived in herds, similar to modern elephants. Cuvieronius frequently co-occurred alongside other megafauna species, such as the similarly sized elephantine giant ground sloth Eremotherium, the car-sized glyptodont Glyptotherium, and the rhinoceros-like ungulate Mixotoxodon. == Extinction ==

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. Some authors suggest that the species may have survived into the early Holocene in Central America, based on a molar and tusk from the La Estanzuela site in southern-central Guatemala that have been radiocarbon dated to 11,206-11,163 years Before Present (9,256-9,213 calibrated years BC), and 11,067-10,743 years Before Present (9,117–8,793 calibrated years BC) respectively, though this dating is based on enamel tooth apatite, which is more prone to date-altering contamination than dates based on collagen. == References ==