Elephantidae

Elephantidae Temporal range: Late Miocene–Holocene PreꞒ Ꞓ O S D C P T J K Pg N
A male Asian elephant (Elephas maximus) in the wild at Bandipur National Park in India
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Proboscidea
Superfamily:	Elephantoidea
Family:	Elephantidae Gray, 1821
Type genus
Elephas Linnaeus, 1758
Genera[3]
Elephas Linnaeus, 1758 Loxodonta Anonymous, 1827 †Mammuthus Brookes, 1828 †Palaeoloxodon Matsumoto, 1925 †Phanagoroloxodon Garutt, 1957 †Primelephas Maglio, 1970 †Selenetherium Mackaye, Brunet & Tassy, 2005[1] †Stegoloxodon Kretzoi, 1950 †Stegodibelodon Coppens, 1972 †Stegotetrabelodon Petrocchi, 1941[2]
Synonyms[4]
Elephasidae Lesson, 1842

Elephantidae is a family of large, herbivorous proboscidean mammals collectively called elephants and mammoths. These are large terrestrial mammals with a snout modified into a trunk and teeth modified into tusks. Most genera and species in the family are extinct. Only two genera, Loxodonta (African elephants) and Elephas (Asian elephants), are living.

The family was first described by John Edward Gray in 1821,^[5] and later assigned to taxonomic ranks within the order Proboscidea. Elephantidae has been revised by various authors to include or exclude other extinct proboscidean genera.

Elephantids are distinguished from more primitive proboscideans like gomphotheres by their teeth, which have parallel lophs, formed from the merger of the cusps found in the teeth of more primitive proboscideans, which are bound by cementum.^[6] In later elephantids, these lophs became narrow lamellae,^[7] with the number of lophs/lamellae per tooth, as well as the tooth crown height (hypsodonty) increasing over time.^[8] Elephantids chew using a proal jaw movement involving a forward stroke of the lower jaws, different from the oblique movement using side to side motion of the jaws in more primitive proboscideans.^[9] The most primitive elephantid Stegotetrabelodon had a long lower jaw with lower tusks and retained permanent premolars similar to many gomphotheres, while modern elephantids lack permanent premolars, with the lower jaw being shortened (brevirostrine) and lower tusks being absent.^[8] Elephantids are typically sexually dimorphic, with substantially larger males, with an accelerated growth rate over a longer period of time than females. Elephantidae contains some of the largest known proboscideans, with fully-grown males of some species of mammoths and Palaeoloxodon having average body masses of 11 tonnes (24,000 lb) and 13 tonnes (29,000 lb) respectively, making them among the largest terrestrial mammals ever. One species of Palaeoloxodon, Palaeoloxodon namadicus, has been suggested to have been possibly the largest land mammal of all time, though this remains speculative due to the fragmentary nature of known remains.^[10] In comparison to more primitive elephantimorphs like gomphotheres, the bodies of elephantids tend to be proportionally shorter, as well having more elongate limbs with more slender limb bones.^[11]

Some authors have suggested to classify the family into two subfamilies, Stegotetrabelodontinae, which is monotypic, only containing Stegotetrabelodon, and Elephantinae, containing all other elephantids.^[8] Recent genetic research has indicated that Elephas and Mammuthus are more closely related to each other than to Loxodonta, with Palaeoloxodon closely related to Loxodonta. Palaeoloxodon also appears to have received extensive hybridisation with the African forest elephant, and to a lesser extent with mammoths.^[12]

• Loxodonta (African)
  • L. africana African bush elephant
  • L. cyclotis African forest elephant
• Elephas (Asiatic)
  • E. maximus Asian elephant
    • E. m. maximus Sri Lankan elephant
    • E. m. indicus Indian elephant
    • E. m. sumatranus Sumatran elephant
    • E. m. borneensis Borneo elephant

• Elephantidae
  • †Stegotetrabelodon (4 species)
  • Subfamily Elephantinae
    • †Primelephas (2 species)
    • Elephas (7+ species)
    • †Stegoloxodon (2 species)
    • Loxodonta (6 species)
    • †Palaeoloxodon (14+ species)
    • †Phanagoroloxodon (1 species)
    • †Mammuthus (10 species)
    • †Stegodibelodon (1 species)
    • †Selenetherium (1 species)

Elephantids are thought to have evolved from gomphotheres, with some authors proposing the most likely ancestors to be African species of the "tetralophodont gomphothere" Tetralophodon.^[13] The earliest members of the family, are known from the Late Miocene, around 9–10 million years ago.^[14] The modern genera of elephants and mammoths had diverged from each other by the end of the Miocene, around 5 million years ago. Elephantids began to migrate out of Africa during the Pliocene, with mammoths and Elephas arriving in Eurasia around 3–3.8 million years ago.^[15] Around 1.5 million years ago, mammoths migrated into North America.^[16] At the end of the Early Pleistocene, around 0.8 million years ago, Palaeoloxodon migrated out of Africa, becoming widespread across Eurasia, from Western Europe to Japan.^[17] Palaeoloxodon and Mammuthus became extinct during the Late Pleistocene-Holocene, with the last population of mammoths persisting on Wrangel Island until around 4,000 years ago.^[18]

• Media related to Elephantidae at Wikimedia Commons
• Data related to Elephantidae at Wikispecies