Elephantidae

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.

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

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.

Description

Elephantids are distinguished from more primitive proboscideans like gomphotheres by their teeth, which have parallel lamellae (homologous to the cusp pairs of more primitive proboscideans) bound by cement, allowing them to become more hypsodont (high-crowned) and more efficient in consuming grass.[5]

Comparison of teeth

Classification
See also: List of elephant species and Elephants
"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

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)

  (African elephants)  
Elephantini
†Palaeoloxodontina        

†Palaeoloxodon

Elephantina
Elephas

(3~6 subspecies)

  (Asian elephants)  
†Mammuthus

  (Mammoths)  
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.[6]

The systematics of the living subspecies and species of the modern elephants has undergone several revisions. A list of the extant Elephantidae includes:[7]

Extinct species

Evolutionary history
Evolution of elephants from the ancient Eocene (bottom) to the modern day (top)

Elephantids are suggested to have evolved from African species of the "tetralophodont gomphothere" Tetralophodon.[8] The earliest members of the family, are known from the Late Miocene, around 9-10 million years ago.[9] While early members of Elephantidae had lower tusks, these were lost in later members.[10] The modern genera of elephants and mammoths had diverged from each other by the end of the Miocene. Elephantids began to migrate out of Africa during the Pliocene, with mammoths and Elephas arriving in Eurasia around 3.8-3 million years ago.[11] Around 1.5 million years ago, mammoths migrated into North America.[12] At the end of the Early Pleistocene, around 0.8 million years ago, Palaeoloxodon migrated out of Africa, becoming widespread across Eurasia.[13] 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.[14]

See also

References
  1. 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. Lister, Adrian M. (2013-06-26). "The role of behaviour in adaptive morphological evolution of African proboscideans". Nature. 500 (7462): 331–334. doi:10.1038/nature12275. ISSN 0028-0836. PMID 23803767. S2CID 883007.
  6. Yates, Diana. "Genetic study shakes up the elephant family tree". news.illinois.edu. Retrieved 2021-09-17.
  7. 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.
  8. Geraads, Denis; Zouhri, Samir; Markov, Georgi N. (2019-05-04). "The first Tetralophodon (Mammalia, Proboscidea) cranium from Africa". Journal of Vertebrate Paleontology. 39 (3): e1632321. doi:10.1080/02724634.2019.1632321. ISSN 0272-4634. S2CID 202024016.
  9. H. Saegusa, H. Nakaya, Y. Kunimatsu, M. Nakatsukasa, H. Tsujikawa, Y. Sawada, M. Saneyoshi, T. Sakai Earliest elephantid remains from the late Miocene locality, Nakali, Kenya Scientific Annals, School of Geology, Aristotle University of Thessaloniki, Greece VIth International Conference on Mammoths and Their Relatives, vol. 102, Grevena -Siatista, special volume (2014), p. 175
  10. Mothé, Dimila; Ferretti, Marco P.; Avilla, Leonardo S. (2016-01-12). Beatty, Brian Lee (ed.). "The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha". PLOS ONE. 11 (1): e0147009. doi:10.1371/journal.pone.0147009. ISSN 1932-6203. PMC 4710528. PMID 26756209.
  11. Iannucci, Alessio; Sardella, Raffaele (March 2023). "What Does the "Elephant-Equus" Event Mean Today? Reflections on Mammal Dispersal Events around the Pliocene-Pleistocene Boundary and the Flexible Ambiguity of Biochronology". Quaternary. 6 (1): 16. doi:10.3390/quat6010016. ISSN 2571-550X.
  12. Lister, A. M.; Sher, A. V. (November 13, 2015). "Evolution and dispersal of mammoths across the Northern Hemisphere". Science. 350 (6262): 805–809. Bibcode:2015Sci...350..805L. doi:10.1126/science.aac5660. PMID 26564853. S2CID 206639522.
  13. Lister, Adrian M. (2004), "Ecological Interactions of Elephantids in Pleistocene Eurasia", Human Paleoecology in the Levantine Corridor, Oxbow Books, pp. 53–60, ISBN 978-1-78570-965-4, retrieved 2020-04-14
  14. Arppe, Laura; Karhu, Juha A.; Vartanyan, Sergey; Drucker, Dorothée G.; Etu-Sihvola, Heli; Bocherens, Hervé (October 2019). "Thriving or surviving? The isotopic record of the Wrangel Island woolly mammoth population". Quaternary Science Reviews. 222: 105884. doi:10.1016/j.quascirev.2019.105884. S2CID 203103403.
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