Proboscidea is a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Proboscideans include some of the largest known land mammals. The largest land mammal of all time may have been a proboscidean; the elephant Palaeoloxodon namadicus has been estimated to be up to 5.2 m (17.1 ft) at the shoulder and may have weighed up to 22 t, surpassing the paraceratheres, the otherwise largest known land mammals, though this estimate was made based on a single fragmentary femur and is speculative. The largest extant proboscidean is the African bush elephant, with a record of size of 4 m (13.1 ft) at the shoulder and 10.4 t. In addition to their enormous size, later proboscideans are distinguished by tusks and long, muscular trunks, which were less developed or absent in early proboscideans.
A mastodon is any proboscidean belonging to the extinct genus Mammut. Mastodons inhabited North and Central America from the late Miocene up to their extinction at the end of the Pleistocene 10,000 to 11,000 years ago. Mastodons are the most recent members of the family Mammutidae, which diverged from the ancestors of elephants at least 25 million years ago. M. americanum, the American mastodon, is the youngest and best-known species of the genus. They lived in herds and were predominantly forest-dwelling animals. M. americanum is inferred to have had a browsing diet with a preference for woody material, distinct from that of the contemporary Columbian mammoth. Mastodons became extinct as part of the Quaternary extinction event that exterminated most Pleistocene megafauna present in the Americas, believed to have been caused by a combination of climate changes at the end of the Pleistocene and hunting by recently arrived Paleo-Indians, as evidenced by a number of kill sites where mastodon remains are associated with human artifacts.
Mammutidae is an extinct family of proboscideans belonging to Elephantimorpha. It is best known for the mastodons, which inhabited North America from the Late Miocene until their extinction at beginning of the Holocene, around 11,000 years ago. The earliest fossils of the group are known from the Late Oligocene of Africa, around 24 million years ago, and fossils of the group have also been found across Eurasia. The name "mastodon" derives from Greek, μαστός "nipple" and ὀδούς "tooth", referring to their characteristic teeth.
Gomphotheres are an extinct group of proboscideans related to modern elephants. They were widespread across Afro-Eurasia and North America during the Miocene and Pliocene epochs and dispersed into South America during the Pleistocene as part of the Great American Interchange. Gomphotheres are a paraphyletic group that is ancestral to Elephantidae, which contains modern elephants, as well as Stegodontidae. While most famous forms such as Gomphotherium had long lower jaws with tusks, which is the ancestral condition for the group, some later members developed shortened (brevirostrine) lower jaws with either vestigial or no lower tusks, looking very similar to modern elephants, an example of parallel evolution, which outlasted the long-jawed gomphotheres. By the end of the Early Pleistocene, gomphotheres became extinct in Afro-Eurasia, with the last two genera, Cuvieronius ranging from southern North America to western South America, and Notiomastodon having a wide range over most of South America until the end of the Pleistocene around 12,000 years ago, when they became extinct following the arrival of humans.
Prodeinotherium is an extinct representative of the family Deinotheriidae that lived in Africa, Europe, and Asia in the early and middle Miocene. Prodeinotherium, meaning "before terrible beast", was first named in 1930, but soon after, the only species in it, P. hungaricum, was reassigned to Deinotherium. During the 1970s, however, the two genera were once again separated, with Prodeinotherium diagnosed to include Deinotherium bavaricum, Deinotherium hobleyi, and Deinotherium pentapotamiae, which were separated based on geographic location. The three species are from Europe, Africa, and Asia, respectively. However, because of usage of few characters to separate them, only one species, P. bavaricum, or many more species, including P. cuvieri, P. orlovii, and P. sinense may be possible.
Gomphotherium is an extinct genus of gomphothere proboscidean from the Neogene of Eurasia, Africa and North America. The genus is probably paraphyletic.
Anancus is an extinct genus of "tetralophodont gomphothere" native to Afro-Eurasia, that lived from the Tortonian stage of the late Miocene until its extinction during the Early Pleistocene, roughly from 8.5–2 million years ago.
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.
Sinomastodon is an extinct gomphothere genus known from the Late Miocene to Early Pleistocene of Asia, including China, Japan, Thailand, Myanmar, Indonesia and probably Kashmir.
Tetralophodon is an extinct genus of "tetralophodont gomphothere" belonging to the superfamily Elephantoidea, known from the Miocene of Afro-Eurasia.
Rhynchotherium is an extinct genus of proboscidea endemic to North America and Central America during the Miocene through Pliocene from 13.650 to 3.6 Ma, living for approximately 10 million years.
Eubelodon is an extinct genus of gomphothere which lived in North America during the Miocene Epoch. It contains a single species: Eubelodon morrilli.
Zygolophodon is an extinct genus of mammutid proboscidean that lived during the Miocene in Africa, Eurasia, and North America.
Notiomastodon is an extinct genus of gomphothere proboscidean, endemic to South America from the Pleistocene to the beginning of the Holocene. Notiomastodon specimens reached a size similar to that of the modern Asian elephant. Like other brevirostrine gomphotheres such as Cuvieronius and Stegomastodon, Notiomastodon had a shortened lower jaw and lacked lower tusks.
Choerolophodon is an extinct genus of proboscidean that lived during the Miocene of Eurasia and Africa. Fossils of Choerolophodon have been found in Africa, Southeast Europe, Turkey, Iraq, Iran, the Indian subcontinent, and China.
Surameryx is an extinct genus of herbivorous artiodactyls originally described as belonging to the extinct family Palaeomerycidae. A single species, S. acrensis, was described from the Late Miocene of the Madre de Dios Formation, South America. It was originally interpreted as one of the few northern mammals that entered South America before the Pliocene. However, both its identification as a member of the family Palaeomerycidae and claims about its Miocene age were subsequently challenged.
Amebelodontidae is an extinct family of large herbivorous proboscidean mammals related to elephants. They were formerly assigned to Gomphotheriidae, but recent authors consider them a distinct family. They are distinguished from other proboscideans by having flattened lower tusks and very elongate mandibular symphysis. The lower tusks could grow considerable size, with those of Konobelodon reaching 1.61 metres (5.3 ft) in length. Their molar teeth are typically trilophodont, and possessed posttrite conules. In the past, amebelodonts' shovel-like mandibular tusks led to them being portrayed scooping up water plants, however, dental microwear suggests that they were browsers and mixed feeders. The lower tusks have been proposed to have had a variety of functions depending on the species, including stripping bark, cutting through vegetation, as well as possibly digging. They first appeared in Africa during the Early Miocene, and subsequently dispersed into Eurasia and then North America. They became extinct by the beginning of the Pliocene. While some phylogenetic studies have recovered Amebelodontidae as a monophyletic group that forms the sister group to Gomphotheriidae proper, some authors have argued that Amebelodontidae may be polyphyletic, with it being suggested that the shovel-tusked condition arose several times independently within Gomphotheriidae, thus rendering the family invalid.
Eozygodon is an extinct genus of proboscidean in the family Mammutidae that is based on a single species, E. morotoensis, named in 1983. It is known from the Early Miocene of Africa and well as possibly the Middle Miocene of China. It is considered a primitive member of the family, retaining a long lower jaw (longirostrine) with lower tusks. The upper tusks are small and are parallel to each other. The body mass is considerably smaller than the American mastodon. Dental mesowear from East African specimens suggests a browsing diet.
"Mammut" borsoni is an extinct species of mammutid proboscidean known from the Late Miocene to Early Pleistocene of Eurasia, spanning from western Europe to China. It is the last known mammutid in Eurasia, and amongst the largest of all proboscideans.
