Elephas is a genus of and one of two surviving genera in the family Elephantidae, comprising one extant species, the Asian elephant ( E. maximus).
Description
Species of
Elephas have distinct bossing of the parieto-occipital region of the skull. The
bones containing the tusks are tapered.
Evolutionary history
Relationships of living and extinct elephantids based on DNA, after Palkopoulou et al. 2018.
Asian elephants share a closer common ancestry with
(genus
Mammuthus) than they do with
(
Loxodonta).
The oldest species attributed to the genus
Elephas is
E. nawataensis from the Late
Miocene-Early
Pliocene of Kenya, though the validity of this species and its relationship to
Elephas has been doubted.
The oldest species widely attributed to the genus,
Elephas ekorensis is known from the early-mid Pliocene (5–4.2 million years ago) of East Africa
, though the attribution of this species to
Elephas has been questioned, due to a lack of shared morphological features with later
Elephas species.
The oldest record of the genus outside of Africa is
Elephas planifrons which is known from the Late Pliocene of the Indian subcontinent, around 3.6 million years ago.
However, the placement of
Elephas planifrons within the genus has also been questioned.
[H. Zhang Elephas recki: the wastebasket? 66th Symposium of Vertebrate Palaeontology and Comparative Anatomy, Manchester. (2018)] The earliest fossils of the ancestor of the modern Asian elephant,
Elephas hysudricus date to the beginning of the Pleistocene, around 2.6 million years ago, with remains found on the Indian subcontinent.
Modern Asian elephants had evolved from
E. hysrudicus by the
Late Pleistocene.
Taxonomy
The scientific name
Elephas was proposed by
Carl Linnaeus in 1758 who described the genus and an elephant from
Ceylon.
The genus is assigned to the
family
Elephantidae and is made up of one living and seven extinct species:
[Maglio, V.J. (1973). "Origin and evolution of the Elephantidae". Transactions of the American Philosophical Society, Philadelphia Volume 63. American Philosophical Society, Philadelphia, pp. 149]
-
Asian elephant – Asian elephant
[
]
-
Indian elephant – Indian elephant
-
Elephas maximus maximus – Sri Lankan elephant
-
Elephas maximus sumatranus – Sumatran elephant
-
Borneo elephant – Borneo elephant, proposed but not yet recognized as valid
[Fernando, P., Vidya, T.N.C., Payne, J., Stuewe, M., Davison, G., et al. (2003). DNA Analysis Indicates That Asian Elephants Are Native to Borneo and Are Therefore a High Priority for Conservation. PLoS Biol 1 (#1): e6]
The following Asian elephants were proposed as
extinct subspecies, but are now considered synonymous with the Indian elephant:
[
]
The following Elephas species are extinct:
-
Elephas beyeri? – possible dwarf elephant species described by von Königswald in 1956 from a single now lost cheek tooth found in the northern Philippines.
[Von Königswald, G.H.R. (1956). Fossil mammals from the Philippines. National Research Council of the Philippines, Manila]
-
Elephas ekorensis – described from the Kubi Algi Formation, Turkana District, Kenya,
[ dating to the Early Pliocene, one of the oldest species of the genus.]
-
Elephas hysudricus – described from fossil remains found in the Siwalik hills of the northern Indian subcontinent by Hugh Falconer and Proby Cautley, 1845,
[Falconer, H. & Cautley, P. T. (1846). Fauna Antiqua Sivalensis, Being the Fossil Zoology of the Sewalik Hills. Smith, Elder & Company, London, pp. 64.] thought to be the ancestor of the living Asian elephant.
-
Elephas hysudrindicus – a fossil elephant of the Pleistocene of Java and different from Elephas maximus sondaicus
[Hooijer, D. A. (1955). Fossil Proboscidea from the Malay Archipelago and the Punjab. Zoologische Verhandelingen, 28 (#1): 1–146.]
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Elephas planifrons - one of the oldest species, known from the Late Pliocene-Early Pleistocene of the Indian subcontinent.
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Elephas platycephalus a species sometimes recognised from the Pleistocene of India
-
Elephas kiangnanensis a species sometimes recognised from the Early-Middle Pleistocene of China.
[Haowen Tong & M. Patou-Mathis. (2003). Mammoth and other proboscideans in China during the Late Pleistocene. Deinsea, 9(1), 421–428.]
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Elephas nawataensis a species of elephant known from the Late Miocene-Early Pliocene of Kenya, though other authors argue that this species is actually a synonym of Primelephas korotorensis.
-
Elephas atavus? known from the Early Pleistocene of Africa, traditionally considered part of Elephas/Palaeoloxodon recki
While formerly assigned to this genus, Elephas recki, Elephas namadicus, the straight-tusked elephant E. antiquus and the E. falconeri and E. cypriotes are now placed in the separate genus Palaeoloxodon, which is more closely related to African elephants.
