Elephas planifrons
{{Short description|Extinct species of mammal}}
{{speciesbox
| fossil_range = {{fossilrange|Late Pliocene|Early Pleistocene}}
| image = Elephas planifrons teeth - Falconer and Cautley 1845 pl 10.png
| image_caption = Partial skull in various views
| extinct = yes
| taxon = Elephas planifrons
| authority = Falconer & Cautley, 1846
}}
Elephas planifrons is an extinct species of elephant, known from the Late Pliocene-Early Pleistocene of the Indian subcontinent and probably South East Asia (Java, Indonesia).
Description
The number of lamellae on the third molars is typically in the range of 11 to 15.{{Cite journal |last1=Rabinovich |first1=Rivka |last2=Lister |first2=Adrian M. |date=July 2017 |title=The earliest elephants out of Africa: Taxonomy and taphonomy of proboscidean remains from Bethlehem |url=https://linkinghub.elsevier.com/retrieve/pii/S1040618216308370 |journal=Quaternary International |language=en |volume=445 |pages=23–42 |doi=10.1016/j.quaint.2016.07.010|bibcode=2017QuInt.445...23R |url-access=subscription }} Members of the species retained permanent premolars, unlike living Asian elephants.{{Cite journal |last=Sanders |first=William J. |date=2018-02-17 |title=Horizontal tooth displacement and premolar occurrence in elephants and other elephantiform proboscideans |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2017.1297436 |journal=Historical Biology |language=en |volume=30 |issue=1–2 |pages=137–156 |doi=10.1080/08912963.2017.1297436 |bibcode=2018HBio...30..137S |issn=0891-2963|url-access=subscription }}
Ecology
Isotopic evidence suggests that the species had a grazing based diet.{{Cite journal |last1=Patnaik |first1=Rajeev |last2=Singh |first2=Ningthoujam Premjit |last3=Paul |first3=Debajyoti |last4=Sukumar |first4=Raman |date=November 2019 |title=Dietary and habitat shifts in relation to climate of Neogene-Quaternary proboscideans and associated mammals of the Indian subcontinent |url=https://linkinghub.elsevier.com/retrieve/pii/S027737911930263X |journal=Quaternary Science Reviews |language=en |volume=224 |pages=105968 |doi=10.1016/j.quascirev.2019.105968|bibcode=2019QSRv..22405968P |url-access=subscription }}
Evolution
Elephas planifrons represents one of the earliest dispersals of elephants outside of Africa, first arriving on the Indian subcontinent around 3.6 million years ago{{Cite journal |last1=Iannucci |first1=Alessio |last2=Sardella |first2=Raffaele |date=2023-02-28 |title=What Does the "Elephant-Equus" Event Mean Today? Reflections on Mammal Dispersal Events around the Pliocene-Pleistocene Boundary and the Flexible Ambiguity of Biochronology |journal=Quaternary |language=en |volume=6 |issue=1 |pages=16 |doi=10.3390/quat6010016 |doi-access=free |issn=2571-550X|hdl=11573/1680082 |hdl-access=free }} (though some authors have suggested a much earlier age over 5 million years ago). The date of the last record of the species is highly uncertain, with estimates ranging from 2.5 million to 800,000 years ago.{{Citation |last=Patnaik |first=Rajeev |title=Early Pleistocene Mammalian Faunas of India and Evidence of Connections with Other Parts of the World |date=2010 |work=Out of Africa I |pages=129–143 |editor-last=Fleagle |editor-first=John G. |url=http://link.springer.com/10.1007/978-90-481-9036-2_9 |access-date=2024-09-26 |place=Dordrecht |publisher=Springer Netherlands |doi=10.1007/978-90-481-9036-2_9 |isbn=978-90-481-9035-5 |last2=Nanda |first2=Avinash C. |editor2-last=Shea |editor2-first=John J. |editor3-last=Grine |editor3-first=Frederick E. |editor4-last=Baden |editor4-first=Andrea L.|url-access=subscription }} While only definitvely reported from the Indian subcontinent, possible E. planifrons remains have been reported from Indonesia, and the species may be closely related to the Indonesian dwarf elephant genus Stegoloxodon. A 2020 PhD thesis suggested that the species was not a true member of the genus Elephas, but should instead be considered a member of the genus Phanagoroloxodon with the African Pliocene species "Elephas" recki brumpti considered to be a synonym of "E". planifrons. However, its placement in Phanagoroloxodon and its synonymity with "E". recki brumpti have been rejected by other authors, though the two species may be closely related.{{Cite book |last=Sanders |first=William J. |url=https://www.taylorfrancis.com/books/9781315118918 |title=Evolution and Fossil Record of African Proboscidea |date=2023-07-07 |publisher=CRC Press |isbn=978-1-315-11891-8 |edition=1 |location=Boca Raton |pages=267–293 |language=en |doi=10.1201/b20016}} Additional specimen mentioned as E. planifrons was found in Indonesia (Semedo, Central Java) although further research is required.{{Cite journal |last=Siswanto |first=M.A Siswanto |date=December 2014 |title=Fosil Proboscidea dari Situs Semedo: Hubungannya dengan Biostratigrafi dan Kehadiran Manusia di Jawa |url=https://www.researchgate.net/publication/323634066_Fosil_Proboscidea_dari_Situs_Semedo_Hubungannya_dengan_Biostratigrafi_dan_Kehadiran_Manusia_di_Jawa |journal=Berkala Arkeologi |volume=34 |issue=2 |pages=115 |via=ResearchGate}}