- Molar of Tetralophodon , a "tetralophodont gomphothere"
- Worn molar of Stegotetrabelodon , a primitive elephantid
- Molar of a modern African bush elephant (Loxodonta africana)
- Tooth of Mammuthus sp.
- Cross section through elephantid molars
Elephantidae Temporal range: | |
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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 | |
Genera [1] | |
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Synonyms [4] | |
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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 from front to back, 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]
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]
A mammoth is any species of the extinct elephantid genus Mammuthus. They lived from the late Miocene epoch into the Holocene until about 4,000 years ago, with mammoth species at various times inhabiting Africa, Asia, Europe, and North America. Mammoths are distinguished from living elephants by their spirally twisted tusks and in at least some later species, the development of numerous adaptions to living in cold environments, including a thick layer of fur.
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. Three species of elephant are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant.
A mastodon is a member of the genus Mammut, which was endemic to North America and lived from the late Miocene to the early Holocene. Mastodons belong to the order Proboscidea, the same order as elephants and mammoths. Mammut is the type genus of the extinct family Mammutidae, which diverged from the ancestors of modern elephants at least 27–25 million years ago, during the Oligocene.
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.
Elephas is one of two surviving genera in the family of elephants, Elephantidae, with one surviving species, the Asian elephant, Elephas maximus. Several extinct species have been identified as belonging to the genus, extending back to the Pliocene or possibly the late Miocene.
Palaeoloxodon is an extinct genus of elephant. The genus originated in Africa during the Early Pleistocene, and expanded into Eurasia at the beginning of the Middle Pleistocene. The genus contains the largest known species of elephants, over 4 metres (13 ft) tall at the shoulders and over 13 tonnes (29,000 lb) in weight, representing among the largest land mammals ever, including the African Palaeoloxodon recki, the European straight-tusked elephant and the South Asian Palaeoloxodon namadicus. P. namadicus has been suggested to be the largest known land mammal by some authors based on extrapolation from fragmentary remains, though these estimates are highly speculative. In contrast, the genus also contains many species of dwarf elephants that evolved via insular dwarfism on islands in the Mediterranean, some like Palaeoloxodon falconeri less than 1 metre (3.3 ft) in shoulder height as fully grown adults, making them the smallest elephants known. The genus has a long and complex taxonomic history, and at various times, it has been considered to belong to Loxodonta or Elephas, but today is usually considered a valid and separate genus in its own right.
Stegodon is an extinct genus of proboscidean, related to elephants. It was originally assigned to the family Elephantidae along with modern elephants but is now placed in the extinct family Stegodontidae. Like elephants, Stegodon had teeth with plate-like lophs that are different from those of more primitive proboscideans like gomphotheres and mammutids. Fossils of the genus are known from Africa and across much of Asia, as far southeast as Timor. The oldest fossils of the genus are found in Late Miocene strata in Asia, likely originating from the more archaic Stegolophodon, subsequently migrating into Africa. While the genus became extinct in Africa during the Pliocene, Stegodon persisted in South, Southeast and Eastern Asia into the Late Pleistocene.
Gomphotheres are an extinct group of proboscideans related to modern elephants. First appearing in Africa during the Oligocene, they dispersed into Eurasia and North America during the Miocene and arrived in South America during the Pleistocene as part of the Great American Interchange. Gomphotheres are a paraphyletic group ancestral to Elephantidae, which contains modern elephants, as well as Stegodontidae.
Palaeoloxodon recki, often known by the synonym Elephas recki, is an extinct species of elephant native to Africa and West Asia from the Pliocene or Early Pleistocene to the Middle Pleistocene. During most of its existence, the species represented the dominant elephant species in East Africa. The species is divided into five roughly chronologically successive subspecies. While the type and latest subspecies P. recki recki as well as the preceding P. recki ileretensis are widely accepted to be closely related and ancestral to Eurasian Palaeoloxodon, the relationships of the other, chronologically earlier subspecies to P. recki recki, P. recki ileretensis and Palaeoloxodon are uncertain, with it being suggested they are unrelated and should be elevated to separate species.
The straight-tusked elephant is an extinct species of elephant that inhabited Europe and Western Asia during the Middle and Late Pleistocene. One of the largest known elephant species, mature fully grown bulls on average had a shoulder height of 4 metres (13 ft) and a weight of 13 tonnes (29,000 lb). Straight-tusked elephants likely lived very similarly to modern elephants, with herds of adult females and juveniles and solitary adult males. The species was primarily associated with temperate and Mediterranean woodland and forest habitats, flourishing during interglacial periods, when its range would extend across Europe as far north as Great Britain and Denmark and eastwards into Russia, while persisting in southern Europe during glacial periods. Skeletons found in association with stone tools and in once case, a wooden spear, suggest they were scavenged and hunted by early humans, including Homo heidelbergensis and their Neanderthal successors.
Gomphotherium is an extinct genus of gomphothere proboscidean from the Neogene of Eurasia, Africa and North America. It is the most diverse genus of gompothere, with over a dozen valid species. 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.
Mammuthus meridionalis, sometimes called the southern mammoth, is an extinct species of mammoth native to Eurasia, including Europe, during the Early Pleistocene, living from around 2.5 million years ago to 800,000 years ago.
Mammuthus africanavus is a species of mammoth known from remains spanning the Late Pliocene-Early Pleistocene found in Central and North Africa in the countries of Chad, Morocco, Tunisia and Algeria. It was originally described by Camille Arambourg in 1952 based on remains found around Lake Ichkeul in north Tunisia as a species of Elephas. Some specimens from this sample may genuinely represent Elephas rather than Mammuthus, though the holotype has been argued to likely represent a true mammoth. Some authors have argued that the species should be placed in Loxodonta, reflecting the difficulty in distinguishing the teeth of early elephantids. It is distinguished from the earlier Mammuthus subplanifrons by having a higher number of ridges/lamellae on the teeth, which display a greater parallelity, the molars being more hypsodont, with the molars having a greater amount of cementum and thinner enamel, and the molar plates exhibit closer spacing.
Stegotetrabelodon is an extinct genus of primitive elephantid from the Late Miocene to Early Pliocene of Africa, the Arabian Peninsula, and Italy.
Tetralophodon is an extinct genus of "tetralophodont gomphothere" belonging to the superfamily Elephantoidea, known from the Miocene of Afro-Eurasia.
Primelephas is a genus of Elephantinae that existed during the Miocene and Pliocene epochs. The name of the genus suggests 'first elephant'. These primitive elephantids are thought to be the common ancestor of Mammuthus, the mammoths, and the closely allied genera Elephas and Loxodonta, the Asian and African elephants, diverging some 4-6 million years ago. It had four tusks, which is a trait not shared with its descendants, but common in earlier proboscideans. The type species, Primelephas gomphotheroides, was described by Vincent Maglio in 1970, with the specific epithet indicating the fossil specimens were gomphothere-like. Primelephas korotorensis is the only other species to be assigned to the genus. All fossils found of the Primelephas have been found in Africa, primarily in modern day Chad, Tanzania, Kenya, Ethiopia, and Uganda.
Stegodontidae is an extinct family of proboscideans from Africa and Asia from the Early Miocene to the Late Pleistocene. It contains two genera, the earlier Stegolophodon, known from the Miocene of Asia and the later Stegodon, from the Late Miocene to Late Pleistocene of Africa and Asia which is thought to have evolved from the former. The group is noted for their plate-like lophs on their teeth, which are similar to elephants and different from those of other extinct proboscideans like gomphotheres and mammutids, with both groups having a proal jaw movement utilizing forward strokes of the lower jaw. These similarities with modern elephants were probably convergently evolved. Like elephantids, stegodontids are thought to have evolved from gomphothere ancestors.
Pediolophodon is an extinct gomphotheriid proboscidean genus from the middle to late Miocene of North America. Pediolophodon was a close relative of elephants and would have appeared superficially similar to them, but was not itself a true elephant.
Phanagoroloxodon is a genus of extinct elephant. It is known from one species, Phanagoroloxodon mammontoides, which is described from a partial skull from Russia, of probable Late Pliocene-Early Pleistocene age.