Elephantidae

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Elephantidae
Temporal range: Pliocene–Holocene
Elephas maximus (Bandipur).jpg
A male Asian elephant (Elephas maximus) in the wild at Bandipur National Park in India
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Superfamily: Elephantoidea
Family: Elephantidae
Gray, 1821
Type genus
Elephas
Genera [1]
Synonyms [3]
  • Elephasidae Lesson, 1842

Elephantidae is a family of large, herbivorous mammals collectively called elephants and mammoths. These are terrestrial large 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 (Asiatic elephants), are living.

Contents

The family was first described by John Edward Gray in 1821, [4] 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.

Classification

"Man, and the elephant" plate from Hawkins A comparative view of the human and animal frame, 1860 Comparative view of the human and elephant frame, Benjamin Waterhouse Hawkins, 1860.jpg
"Man, and the elephant" plate from Hawkins A comparative view of the human and animal frame, 1860
Skeleton of Mammuthus meridionalis at the French Museum of Natural History Mammuthus meridionalis.JPG
Skeleton of Mammuthus meridionalis at the French Museum of Natural History

Scientific classification of Elephantidae taxa embraces an extensive record of fossil specimens, over millions of years, some of which existed until the end of the last ice age. Some species were extirpated more recently. The discovery of new specimens and proposed cladistics have resulted in systematic revisions of the family and related proboscideans.

Elephantids are classified informally as the elephant family, or in a paleobiological context as elephants and mammoths. The common name elephant primarily refers to the living taxa, the modern elephants, but may also refer to a variety of extinct species, both within this family and in others. Other members of the Elephantidae, especially members of the genus Mammuthus, are commonly called mammoths.

The family diverged from a common ancestor of the mastodons of Mammutidae. The classification of proboscideans is unstable and has been frequently revised.

The following cladogram shows the placement of the genus Mammuthus among other proboscideans, based on a 2007 study of hyoid characteristics: [1]

Elephantidae
Elephantinae
Loxodontini

Loxodonta (2 species) Elephas africanus - 1700-1880 - Print - Iconographia Zoologica - (white background).jpg

  (African elephants)  
Elephantini
Palaeoloxodontina    

Palaeoloxodon Elephas-antiquus.jpg

Elephantina
Elephas

(3~6 subspecies) Indian elephant white background.jpg

  (Asian elephants)  

Mammuthus trogontherii122DB.jpg

  (Mammoths)  
The most accurate phylogenetic tree of the elephants and mammoths as of 2010 Phylogenetic Tree of Elephants and Mammoths 2010.png
The most accurate phylogenetic tree of the elephants and mammoths as of 2010

However, a 2017 study of mitochondrial and nuclear DNA placed Palaeoloxodon as more closely related to Loxodonta (in particular, the African forest elephant) than to Elephantina. [5]

The systematics of the living subspecies and species of the modern elephants has undergone several revisions. A list of the extant Elephantidae includes: [6]

Elephantidae
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

Evolutionary history

Evolution of elephants from the ancient Eocene (bottom) to the modern day (top) ElephEvol.jpg
Evolution of elephants from the ancient Eocene (bottom) to the modern day (top)

Although the fossil evidence is uncertain, by comparing genes, scientists have discovered evidence that elephantids and other proboscideans share a distant ancestry with Sirenia (sea cows) and Hyracoidea (hyraxes). [7] These have been assigned, along with the extinct demostylians and embrithopods, to the clade Paenungulata. In the distant past, members of the various hyrax families grew to large sizes, and the common ancestor of all three modern families is thought to have been some kind of amphibious hyracoid.[ citation needed ] One hypothesis is that these animals spent most of their time under water, using their trunks like snorkels for breathing. [8] [9] Modern elephants have this ability and are known to swim in that manner for up to six hours and 50 km (31 mi).

In the past, a much wider variety of genera and species was found, including the mammoths and stegodons. [10] [11]

See also

Related Research Articles

Elephant Large terrestrial mammals with trunks from Africa and Asia

Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are an informal grouping within the family Elephantidae of the order Proboscidea. Elephantidae is the only surviving family of proboscideans; extinct members include the mastodons. Elephantidae also contains several extinct groups, including the mammoths and straight-tusked elephants. African elephants have larger ears and concave backs, whereas Asian elephants have smaller ears, and convex or level backs. Distinctive features of all elephants include a long proboscis called a trunk, tusks, large ear flaps, massive legs, and tough but sensitive skin. The trunk is used for breathing, bringing food and water to the mouth, and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. The pillar-like legs carry their great weight.

Mammoth Extinct genus of mammals

A mammoth is any species of the extinct elephantid genus Mammuthus, one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks and, in northern species, a covering of long hair. They lived from the Pliocene epoch into the Holocene at about 4,000 years ago, and various species existed in Africa, Europe, Asia, and North America. They were members of the family Elephantidae, which also contains the two genera of modern elephants and their ancestors. Mammoths are more closely related to living Asian elephants than African Elephants.

Proboscidea Order of elephant-like mammals

The Proboscidea are 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. From the mid-Miocene onwards, most proboscideans were very large. The largest land mammal of all time may have been a proboscidean; Palaeoloxodon namadicus was up to 5.2 m (17.1 ft) at the shoulder and may have weighed up to 22 t, almost double the weight of several sauropods including Diplodocus carnegii and Apatosaurus louisae. 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.

Mastodon Genus of mammals (fossil)

A mastodon is any proboscidean belonging to the extinct genus Mammut that inhabited North and Central America during the late Miocene or late Pliocene up to their extinction at the end of the Pleistocene 10,000 to 11,000 years ago. Mastodons lived in herds and were predominantly forest-dwelling animals that lived on a mixed diet obtained by browsing and grazing, somewhat similar to their distant relatives, modern elephants, but probably with greater emphasis on browsing.

<i>Elephas</i> Genus of mammals

Elephas is one of two surviving genera in the family of elephants, Elephantidae, with one surviving species, the Asian elephant, Elephas maximus.

<i>Palaeoloxodon</i> Genus of extinct elephants

Palaeoloxodon is an extinct genus that contains the various species of straight-tusked elephants. The genus originated in Africa during the Pliocene era, and expanded into Eurasia during the Pleistocene era. One species, Palaeoloxodon namadicus, was possibly the largest known land mammal. 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 considered distinct.

<i>Stegodon</i> Genus of extinct elephant

Stegodon, meaning "roofed tooth" because of the distinctive ridges on the animal's molars, is a genus of the extinct subfamily Stegodontinae of the order Proboscidea. It was assigned to the family Elephantidae, but has also been placed in the Stegodontidae. Stegodonts were present from 11.6 million years ago (Mya) to the late Pleistocene, with unconfirmed records of localized survival until 4,100 years ago. Fossils are found in Asian and African strata dating from the late Miocene; during the Pleistocene, they lived across large parts of Asia and East and Central Africa, and in Wallacea as far east as Timor.

Dwarf elephant Prehistoric elephant species

Dwarf elephants are prehistoric members of the order Proboscidea which, through the process of allopatric speciation on islands, evolved much smaller body sizes in comparison with their immediate ancestors. Dwarf elephants are an example of insular dwarfism, the phenomenon whereby large terrestrial vertebrates that colonize islands evolve dwarf forms, a phenomenon attributed to adaptation to resource-poor environments and selection for early maturation and reproduction. Some modern populations of Asian elephants have also undergone size reduction on islands to a lesser degree, resulting in populations of pygmy elephants.

<i>Palaeoloxodon recki</i> Extinct species of mammal

Palaeoloxodon recki is an extinct species of elephant native to Africa during the Pliocene and Pleistocene. At up to 14 feet in shoulder height, it was one of the largest elephant species to have ever lived. It is believed that P. recki ranged throughout Africa between 3.5 and 1 million years ago. P. recki was a successful grass-eating elephant until it became extinct, perhaps by competition with members of the genus Loxodonta, the African elephants of today. Its descendant taxon, "Elephas" jolensis persisted into the late Middle Pleistocene, c. 205-130 kya in Kenya, after which it was replaced by Loxodonta africana after a severe drought period. P. recki is believed to be the ancestral species from which the Palaeoloxodon species of Eurasia are derived.

Columbian mammoth Extinct species of mammoth that inhabited North America

The Columbian mammoth is an extinct species of mammoth that inhabited North America as far north as the Northern United States and as far south as Costa Rica during the Pleistocene epoch. It was one of the last in a line of mammoth species, beginning with Mammuthus subplanifrons in the early Pliocene. DNA studies show that the Columbian mammoth was a hybrid species between woolly mammoths and another lineage descended from steppe mammoths; the hybridization happened more than 420,000 years ago. The pygmy mammoths of the Channel Islands of California evolved from Columbian mammoths. The closest extant relative of the Columbian and other mammoths is the Asian elephant.

Straight-tusked elephant Extinct species of mammal

The straight-tusked elephant is an extinct species of elephant that inhabited Europe and Western Asia during the Middle and Late Pleistocene. Recovered individuals have reached up to 4–4.2 metres (13.1–13.8 ft) in height, and an estimated 11.3–15 tonnes in weight. The straight-tusked elephant probably lived in small herds, flourishing in interglacial periods, when its range would extend as far as Great Britain. Isolated tusks are often found while partial or whole skeletons are rare, and there is evidence of predation by early humans. It is the ancestral species of most dwarf elephants that inhabited islands in the Mediterranean.

<i>Mammuthus meridionalis</i> Extinct species of mammal

Mammuthus meridionalis, or the southern mammoth, is an extinct species of mammoth native to Europe and Central Asia from the Gelasian stage of the Early Pleistocene, living from 2.5–0.8 mya.

Steppe mammoth Extinct species of mammal

The steppe mammoth is an extinct species of Elephantidae that ranged over most of northern Eurasia during the late Early and Middle Pleistocene, approximately 1.8 million-200,000 years ago. It evolved in Siberia during the Early Pleistocene from Mammuthus meridionalis. It was the first stage in the evolution of the steppe and tundra elephants and the ancestor of the woolly mammoth and Columbian mammoth of the later Pleistocene. Populations of steppe mammoth may have persisted in northern China and Mongolia as recently as 33,000 years ago.

Jeheskel Shoshani Israeli terrorist victim, biologist (1942–2008)

Jeheskel "Hezy" Shoshani was an evolutionary biologist who studied elephants and their relatives for over 35 years.

<i>Primelephas</i> Extinct genus of mammals

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 unusual for an elephant. 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.

Elephas celebensis or the Sulawesi dwarf elephant is an extinct species of elephant.

Stegodontidae is an extinct family of Stegodon-like proboscideans that was endemic to Africa and Asia from the Miocene (15.97 mya) to the Late Pleistocene, with some studies suggesting that some survived into the Holocene in China, although this is disputed.

<i>Palaeoloxodon naumanni</i> Extinct species of mammal

Palaeoloxodon naumanni, occasionally called Naumann's elephant, is an extinct species belonging to the genus Palaeoloxodon found in the Japanese archipelago during the Middle to Late Pleistocene around 430,000 to 24,000 years ago. It is named after Heinrich Edmund Naumann who discovered the first fossils at Yokosuka, Kanagawa, Japan. Fossils attributed to P. naumanni are also known from China.

<i>Mammuthus creticus</i> Extinct species of mammal

Mammuthus creticus, or the Cretan dwarf mammoth, is an extinct species of dwarf mammoth. With a shoulder height of about 1 m and a weight of about 310 kg, it was the smallest mammoth that ever existed.

References

  1. 1 2 Shoshani, J.; Ferretti, M.P.; Lister, A.M.; Agenbroad, L.D.; Saegusa, H.; Mol, D.; Takahashi, K. (2007). "Relationships within the Elephantinae using hyoid characters". Quaternary International. 169–170: 174–185. Bibcode:2007QuInt.169..174S. doi:10.1016/j.quaint.2007.02.003.
  2. Kalb, J. E., & Froehlich, D. J. (1995). Interrelationships of Late Neogene Elephantoids: New evidence from the Middle Awash Valley, Afar, Ethiopia. Geobios, 28(6), 727–736. doi:10.1016/s0016-6995(95)80068-9
  3. Maglio, Vincent J. (1973). "Origin and Evolution of the Elephantidae". Transactions of the American Philosophical Society. 63 (3): 16. doi:10.2307/1006229. JSTOR   1006229.
  4. Gray, John Edward (1821). "On the natural arrangement of vertebrose animals". London Medical Repository. 15: 297–310.
  5. Yates, Diana. "Genetic study shakes up the elephant family tree". news.illinois.edu. Retrieved 2021-09-17.
  6. Shoshani, J. (2005). "Order Proboscidea". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. ISBN   978-0-8018-8221-0. OCLC   62265494.
  7. Ozawa, Tomowo; Hayashi, Seiji; Mikhelson, Victor M. (1997-04-24), "Phylogenetic Position of Mammoth and Steller's Sea Cow Within Tethytheria Demonstrated by Mitochondrial DNA Sequences", Journal of Molecular Evolution, 44 (4): 406–413, Bibcode:1997JMolE..44..406O, doi:10.1007/PL00006160, PMID   9089080, S2CID   417046
  8. West, John B. (2001), "Snorkel breathing in the elephant explains the unique anatomy of its pleura", Respiratory Physiology, 126 (1): 1–8, doi:10.1016/S0034-5687(01)00203-1, PMID   11311306
  9. West, John B.; Fu, Zhenxing; Gaeth, Ann P.; Short, Roger V. (2003-11-14), "Fetal lung development in the elephant reflects the adaptations required for snorkeling in adult life", Respiratory Physiology & Neurobiology, 138 (2–3): 325–333, doi:10.1016/S1569-9048(03)00199-X, PMID   14609520, S2CID   24902376
  10. Todd, N. E. (2001). African Elephas recki: time, space and taxonomy Archived 2008-12-16 at the Wayback Machine (pdf). In: Cavarretta, G., P. Gioia, M. Mussi, and M. R. Palombo. The World of Elephants, Proceedings of the 1st International Congress. Consiglio Nazionale delle Ricerche. Rome, Italy.
  11. Todd, N. E. (2005). Reanalysis of African Elephas recki: implications for time, space and taxonomy. Quaternary International 126-128:65-72.