Jump to content

Palaeoloxodon: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
Restored revision 1183369474 by Hemiauchenia (talk): Restore link - red links are not bad
No edit summary
Tags: Reverted Visual edit Mobile edit Mobile web edit
Line 75: Line 75:


=== Mainland species ===
=== Mainland species ===
* ''[[Palaeoloxodon recki|P. recki]]'' (Synonym:''Elephas recki'') (East Africa), the oldest species and ancestor of all later species
* ''[[Palaeoloxodon recki|P. recki]]'' (Synonym: ''Elephas recki'') (East Africa), the oldest species and ancestor of all later species
* ''[[Palaeoloxodon iolensis|P. iolensis]]'' (Synonym: ''Elephas iolensis'') the last (late Middle-Late Pleistocene) representative of ''Palaeoloxodon'' in Africa
* ''[[Palaeoloxodon iolensis|P. iolensis]]'' (Synonym: ''Elephas iolensis'') the last (late Middle-Late Pleistocene) representative of ''Palaeoloxodon'' in Africa
*''[[Palaeoloxodon antiquus|P. antiquus]]'' (Synonym:''Elephas antiquus'') (Straight tusked elephant) (Europe, Western Asia)
* ''[[Elephas ekorensis|P. ekorensis]]'' (Synonym: ''Elephas'' ''ekorensis'') (East Africa)
*''[[Palaeoloxodon antiquus|P. antiquus]]'' (Synonym: ''Elephas antiquus'') (Straight tusked elephant) (Europe, Western Asia)
* ''[[Palaeoloxodon huaihoensis|P. huaihoensis]]'' (China)
* ''[[Palaeoloxodon huaihoensis|P. huaihoensis]]'' (China)
* ''[[Palaeoloxodon namadicus|P. namadicus]] ''(Synonym:''Elephas namadicus'')<ref>Kevrekidis, C., & Mol, D. (2016). A new partial skeleton of Elephas (Palaeoloxodon) antiquus Falconer and Cautley, 1847 (Proboscidea, Elephantidae) from Amyntaio, Macedonia, Greece. Quaternary International, 406, 35–56. https://doi.org/10.1016/j.quaint.2015.11.110</ref> (Indian subcontinent, possibly also elsewhere in Asia), the largest in its genus, and possibly the largest terrestrial mammal ever
* ''[[Palaeoloxodon namadicus|P. namadicus]] ''(Synonym:''Elephas namadicus'')<ref>Kevrekidis, C., & Mol, D. (2016). A new partial skeleton of Elephas (Palaeoloxodon) antiquus Falconer and Cautley, 1847 (Proboscidea, Elephantidae) from Amyntaio, Macedonia, Greece. Quaternary International, 406, 35–56. https://doi.org/10.1016/j.quaint.2015.11.110</ref> (Indian subcontinent, possibly also elsewhere in Asia), the largest in its genus, and possibly the largest terrestrial mammal ever

Revision as of 15:30, 7 November 2023

Palaeoloxodon
Temporal range: Middle Pliocene–Holocene
Skeleton of Palaeoloxodon huaihoensis at National Museum of Natural Science
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Clade: Elephantida
Superfamily: Elephantoidea
Family: Elephantidae
Genus: †Palaeoloxodon
Matsumoto, 1924[1]
Type species
Elephas namadicus naumanni
Makiyama, 1924
Species

See text

Palaeoloxodon is an extinct genus of elephant. The genus originated in Africa during the Pliocene, and expanded into Eurasia during the Pleistocene. The genus contains some of the largest known species of elephants, over 4 metres (13 ft) tall at the shoulders, including the European straight-tusked elephant (Palaeoloxodon antiquus) and the South Asian Palaeoloxodon namadicus, the latter of which has been suggested to be the largest known land mammal based on extrapolation from fragmentary remains, though these estimates are highly speculative.[2][3] In contrast, the genus also contains many species of dwarf elephants that evolved via insular dwarfism on islands in the Mediterranean, some only 1 metre (3.3 ft) in height, 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.

Taxonomy

In 1924, Matsumoto Hikoshichirō circumscribed Palaeoloxodon as a subgenus of Loxodonta. It included the "E. antiquus—namadicus group", and he designated the Japanese "E. namadicus naumanni Mak." as its type species.[1]

Palaeoloxodon was later thought to be a subgenus of Elephas, but this was subsequently abandoned.[4] In 2016, a mitochondrial DNA study of the straight-tusked elephant (P. antiquus) found that it was more closely related to the African forest elephant, Loxodonta cyclotis, than the African bush elephant, L. africana. The authors suggested that this invalidated the genus Palaeoloxodon as currently recognized.[5] A second study published in 2018 based on the nuclear genome suggested P. antiquus had a complex hybridization history, with over 60% of its Nuclear DNA coming from a lineage closest to but outside the two extant Loxodonta species, around 6% from Mammuthus and 30% from L. cyclotis. The ancestry from L. cyclotis was more closely related to modern West African populations of the forest elephant than to other forest elephant populations. The hybridisation probably took place in Africa, where Palaeoloxodon was dominant for most of the Pliocene and Early Pleistocene.[6]

Further analysis of mitochondrial genomes, including Palaeoloxodon individuals from Northern China found that Palaeoloxodon individuals harboured multiple separate mitochondrial genome lineages, some being more closely related to some West African forest elephant groups than to others. It is unclear as to whether this is the result of multiple hybridisation events, or whether multiple mitochondrial lineages were introgressed in a single event. The analysis found that the mitochondrial genome of the Chinese Palaeoloxodon specimens clustered with a P. antiquus individual from western Europe, which belonged to a separate clade than other sampled European P. antiquus specimens. The relatively low divergence between the mitochondrial genomes of the European P. antiquus individual and the Chinese Palaeoloxodon specimens may indicate that the populations of Palaeoloxodon across Eurasia maintained gene flow with each other, but this is uncertain.[7]

Diagram of overall relationships between elephant genera based on nuclear genomes (ignoring hybridisation) after Palkopoulou et al. 2018:[6]

Elephantidae

Elephas (Asian elephant)

†Mammuthus (mammoths)

Loxodonta (African elephants)

Diagram of the relationships of elephant mitochondrial genomes, after Lin et al. 2023:[7]

Elephantidae

Elephas (Asian elephant)

Mammuthus (mammoths)

Loxodonta africana (African bush elephant)

Palaeoloxodon+Loxodonta cyclotis

North central African forest elephant clade

Palaeoloxodon antiquus (Germany) + Chinese Palaeoloxodon

West central African forest elephant clade

Western African forest elephant clade

P. antiquus (Germany) + P. cf mnaidriensis (Sicily)

Mainland species

  • P. recki (Synonym: Elephas recki) (East Africa), the oldest species and ancestor of all later species
  • P. iolensis (Synonym: Elephas iolensis) the last (late Middle-Late Pleistocene) representative of Palaeoloxodon in Africa
  • P. ekorensis (Synonym: Elephas ekorensis) (East Africa)
  • P. antiquus (Synonym: Elephas antiquus) (Straight tusked elephant) (Europe, Western Asia)
  • P. huaihoensis (China)
  • P. namadicus (Synonym:Elephas namadicus)[8] (Indian subcontinent, possibly also elsewhere in Asia), the largest in its genus, and possibly the largest terrestrial mammal ever
  • P. naumanni (Synonym:E. namadicus naumanni) (Japan, possibly also China and Korea),[9]
  • ?P. turkmenicus known from a single specimen found in the Middle Pleistocene of Turkmenistan, with possibly attributable remains known from Kashmir, validity uncertain.[10]

Mediterranean island dwarfs

These Mediterranean insular dwarf elephant species are almost certainly descended from P. antiquus

Description

Life restoration of P. namadicus
Skeleton of Palaeoloxodon antiquus
Partial skull of Palaeoloxodon namadicus, showing the parieto-occipital crest at the top of the skull

Most species of Palaeoloxodon are noted for their distinctive parieto-occipital crests present at the top of the cranium, which was used to anchor the splenius as well as possibly the rhomboid muscles to support the skull, which is proportionally large in comparison to other elephants. The development of the crest is variable depending on the species, growth stage and gender, with females and juvenliles having less developed or absent crests.[10] The skull is proportionally short and tall.[11] The tusks have relatively little curvature, and are proportionally large,[10] and somewhat twisted, with the tusk alveoli (sockets) being divergent from each other at least in derived species.[11]

Third molar teeth of Palaeoloxodon huaihoensis

The molar teeth of Palaeoloxodon species typically show a "dot-dash-dot" wear pattern,[12] with the enamel folds concentrated into a major central structure at the midline of the tooth, which are flanked by smaller folds on either side, and the crowns of the tooth are generally proportionally narrow.[13] While during the early evolution of the genus, the molar teeth had a low number of lamellae and were brachydont (low crowned), in Pleistocene species the teeth became very hypsodont (high crowned) and increased the number of lamellae, though the lamellae frequency is distinctly lower than that reached by advanced mammoth species.[11]

Size comparison of the dwarf elephant Palaeoloxodon falconeri, one of the smallest elephants known

Species of Palaeoloxodon varied widely in size. Large bulls of P. recki, P. antiquus and P. namadicus are thought to have been over 4 metres (13 ft) tall at the shoulder and greater than 12 tons in body mass, exceeding the size of the largest known African bush elephants. In a 2015 study, one fragmentary unlocated femur of P. namadicus described in the 19th century was estimated to have belonged to an individual 5.2 metres (17 ft) and 22 tons in weight, exceeding the estimates for the otherwise largest known land mammals, the paraceratheres. However, this estimate is highly speculative and the author suggested that it should be "taken with a grain of salt".[2] In contrast, some of the island dwarf species are the smallest elephants known. The smallest species, P. cypriotes and P. falconeri, were only 1 metre (3.3 ft) tall as fully grown adults,[14][15] with the bulls of P. falconeri only having an estimated body mass of 250 kg (550 lb).[15]

Evolution

Skeleton of Palaeoloxodon recki, the earliest species of Palaeoloxodon

Palaeoloxodon first appears in the fossil record in Africa during the early Pliocene, around 4 Mya as the species Palaeoloxodon recki. P. recki was the dominant elephant in East Africa for the Pliocene and most of the Pleistocene. A population of P. recki migrated out of Africa between 0.8 and 0.6 Mya, diversifying into the radiation of Eurasian Palaeoloxodon species, including P. antiquus, and P. namadicus. The precise relationships of the Eurasian taxa to each other are obscure.[16] The arrival of P. antiquus in Europe co-incides with the extinction of Mammuthus meridionalis and its replacement by Mammuthus trogontherii, suggesting that it might have shared a similar dietary niche and outcompeted the former.[16] P. antiquus was able to disperse onto many islands in the Mediterranean, undergoing insular dwarfism and speciating into numerous distinct varieties of dwarf elephants. Palaeoloxodon fossils are abundant in China and are assigned to three species, P. namadicus, P. naumanni and P. huaihoensis.[17] However, the relationships of Chinese Palaeoloxodon are currently unresolved and it is unclear how many species were present in the region.[10]

Extinction

The last Paleoloxodon species in Africa, P. iolensis, is suggested to have become extinct at the end of the Middle Pleistocene, around 130,000 years ago.[18] Most Eurasian species of Palaeoloxodon became extinct towards the end of the last glacial period. The youngest record of P. antiquus are footprints from the southern Iberian Peninsula, dating to approximately 28,000 years ago.[19] The youngest Japanese records of P. naumanni date to around 24,000 years ago.[20] The timing of extinction of Chinese Palaeoloxodon and Indian P. namadicus is uncertain, but claims of a Holocene survival are not substantiated for either region.[21][22][23] The youngest dates for the Sicilian dwarf elephant P. cf. mnaidriensis date to 32-20,000 years ago,[24] while the youngest dates for the Cyprus dwarf elephant P. cypriotes are around 12,000 years ago.[25] P. tiliensis from the Greek island of Tilos was suggested to have survived as recently as 3,500 years Before Present based on preliminary radiocarbon dating done in the 1970s, which would make it the youngest surviving elephant in Europe, but this has not been thoroughly investigated.[26]

References

  1. ^ a b Matsumoto, Hikoshichiro (1924). 日本産化石象の種類(略報) [Types of fossil elephants from Japan]. 地質学雑誌 (in Japanese). 31 (371): 255–272. doi:10.5575/geosoc.31.371_255.
  2. ^ a b Larramendi, A. (2015). "Shoulder height, body mass and shape of proboscideans". Acta Palaeontologica Polonica. 60. doi:10.4202/app.00136.2014.
  3. ^ "Early signs of elephant butchers". BBC News. 30 June 2006.
  4. ^ 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.
  5. ^ Callaway, E. (2016-09-16). "Elephant history rewritten by ancient genomes". Nature. doi:10.1038/nature.2016.20622. S2CID 89500906.
  6. ^ a b Palkopoulou, Eleftheria; Lipson, Mark; Mallick, Swapan; Nielsen, Svend; Rohland, Nadin; Baleka, Sina; Karpinski, Emil; Ivancevic, Atma M.; To, Thu-Hien; Kortschak, R. Daniel; Raison, Joy M. (2018-03-13). "A comprehensive genomic history of extinct and living elephants". Proceedings of the National Academy of Sciences. 115 (11): E2566–E2574. Bibcode:2018PNAS..115E2566P. doi:10.1073/pnas.1720554115. ISSN 0027-8424. PMC 5856550. PMID 29483247.
  7. ^ a b Lin, Haifeng; Hu, Jiaming; Baleka, Sina; Yuan, Junxia; Chen, Xi; Xiao, Bo; Song, Shiwen; Du, Zhicheng; Lai, Xulong; Hofreiter, Michael; Sheng, Guilian (July 2023). "A genetic glimpse of the Chinese straight-tusked elephants". Biology Letters. 19 (7). doi:10.1098/rsbl.2023.0078. ISSN 1744-957X. PMC 10353889. PMID 37463654.{{cite journal}}: CS1 maint: PMC embargo expired (link)
  8. ^ Kevrekidis, C., & Mol, D. (2016). A new partial skeleton of Elephas (Palaeoloxodon) antiquus Falconer and Cautley, 1847 (Proboscidea, Elephantidae) from Amyntaio, Macedonia, Greece. Quaternary International, 406, 35–56. https://doi.org/10.1016/j.quaint.2015.11.110
  9. ^ van der Geer, A.; Lyras, G. A.; de Vos, J. (2021). "Japan: Honshu, Shikoku, and Kyushu". Evolution of Island Mammals: Adaptation and Extinction of Placental Mammals on Islands. Oxford: Wiley Blackwell. p. 334. ISBN 9781119675730.
  10. ^ a b c d Larramendi, Asier; Zhang, Hanwen; Palombo, Maria Rita; Ferretti, Marco P. (February 2020). "The evolution of Palaeoloxodon skull structure: Disentangling phylogenetic, sexually dimorphic, ontogenetic, and allometric morphological signals". Quaternary Science Reviews. 229: 106090. Bibcode:2020QSRv..22906090L. doi:10.1016/j.quascirev.2019.106090. S2CID 213676377.
  11. ^ a b c Athanassiou, Athanassios (2022), Vlachos, Evangelos (ed.), "The Fossil Record of Continental Elephants and Mammoths (Mammalia: Proboscidea: Elephantidae) in Greece", Fossil Vertebrates of Greece Vol. 1, Cham: Springer International Publishing, pp. 345–391, doi:10.1007/978-3-030-68398-6_13, ISBN 978-3-030-68397-9, S2CID 245067102, retrieved 2023-07-16
  12. ^ Pokines, James T.; Lister, Adrian M.; Ames, Christopher J. H.; Nowell, April; Cordova, Carlos E. (March 2019). "Faunal remains from recent excavations at Shishan Marsh 1 (SM1), a Late Lower Paleolithic open-air site in the Azraq Basin, Jordan". Quaternary Research. 91 (2): 768–791. Bibcode:2019QuRes..91..768P. doi:10.1017/qua.2018.113. ISSN 0033-5894. S2CID 134216492.
  13. ^ Lister, Adrian M.; Dirks, Wendy; Assaf, Amnon; Chazan, Michael; Goldberg, Paul; Applbaum, Yaakov H.; Greenbaum, Nathalie; Horwitz, Liora Kolska (September 2013). "New fossil remains of Elephas from the southern Levant: Implications for the evolutionary history of the Asian elephant". Palaeogeography, Palaeoclimatology, Palaeoecology. 386: 119–130. Bibcode:2013PPP...386..119L. doi:10.1016/j.palaeo.2013.05.013. ISSN 0031-0182.
  14. ^ Scarborough, Matthew Edward (2022-03-11). "Extreme Body Size Variation in Pleistocene Dwarf Elephants from the Siculo-Maltese Palaeoarchipelago: Disentangling the Causes in Time and Space". Quaternary. 5 (1): 17. doi:10.3390/quat5010017. ISSN 2571-550X.
  15. ^ a b Romano, Marco; Manucci, Fabio; Palombo, Maria Rita (2021-03-04). "The smallest of the largest: new volumetric body mass estimate and in-vivo restoration of the dwarf elephant Palaeoloxodon ex gr. P. falconeri from Spinagallo Cave (Sicily)". Historical Biology. 33 (3): 340–353. doi:10.1080/08912963.2019.1617289. ISSN 0891-2963. S2CID 181855906.
  16. ^ a b 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
  17. ^ Kang, Jia-Cih; Lin, Chien-Hsiang; Chang, Chun-Hsiang (2021-04-14). "Age and growth of Palaeoloxodon huaihoensis from Penghu Channel, Taiwan: significance of their age distribution based on fossils". PeerJ. 9: e11236. doi:10.7717/peerj.11236. ISSN 2167-8359. PMC 8052959. PMID 33954049.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  18. ^ Manthi, Fredrick Kyalo; Sanders, William J.; Plavcan, J. Michael; Cerling, Thure E.; Brown, Francis H. (September 2020). "Late Middle Pleistocene Elephants from Natodomeri, Kenya and the Disappearance of Elephas (Proboscidea, Mammalia) in Africa". Journal of Mammalian Evolution. 27 (3): 483–495. doi:10.1007/s10914-019-09474-9. ISSN 1064-7554. S2CID 198190671.
  19. ^ de Carvalho, Carlos Neto; Figueiredo, Silvério; Muniz, Fernando; Belo, João; Cunha, Pedro P.; Baucon, Andrea; Cáceres, Luis M.; Rodriguez-Vidal, Joaquín (2020-07-02). "Tracking the last elephants in Europe during the Würm Pleniglacial: the importance of the Late Pleistocene aeolianite record in SW Iberia". Ichnos. 27 (3): 352–360. doi:10.1080/10420940.2020.1744586. ISSN 1042-0940. S2CID 216504699.
  20. ^ Iwase, Akira; Hashizume, Jun; Izuho, Masami; Takahashi, Keiichi; Sato, Hiroyuki (March 2012). "Timing of megafaunal extinction in the late Late Pleistocene on the Japanese Archipelago". Quaternary International. 255: 114–124. Bibcode:2012QuInt.255..114I. doi:10.1016/j.quaint.2011.03.029.
  21. ^ Jukar, A.M.; Lyons, S.K.; Wagner, P.J.; Uhen, M.D. (January 2021). "Late Quaternary extinctions in the Indian Subcontinent". Palaeogeography, Palaeoclimatology, Palaeoecology. 562: 110137. Bibcode:2021PPP...562k0137J. doi:10.1016/j.palaeo.2020.110137. S2CID 228877664.
  22. ^ Turvey, Samuel T.; Sathe, Vijay; Crees, Jennifer J.; Jukar, Advait M.; Chakraborty, Prateek; Lister, Adrian M. (January 2021). "Late Quaternary megafaunal extinctions in India: How much do we know?". Quaternary Science Reviews. 252: 106740. Bibcode:2021QSRv..25206740T. doi:10.1016/j.quascirev.2020.106740. S2CID 234265221.
  23. ^ Turvey, Samuel T.; Tong, Haowen; Stuart, Anthony J.; Lister, Adrian M. (September 2013). "Holocene survival of Late Pleistocene megafauna in China: a critical review of the evidence". Quaternary Science Reviews. 76: 156–166. Bibcode:2013QSRv...76..156T. doi:10.1016/j.quascirev.2013.06.030. ISSN 0277-3791.
  24. ^ Palombo, Maria Rita; Antonioli, Fabrizio; Di Patti, Carolina; Valeria, Lo Presti; Scarborough, Matthew E. (2021-10-03). "Was the dwarfed Palaeoloxodon from Favignana Island the last endemic Pleistocene elephant from the western Mediterranean islands?". Historical Biology. 33 (10): 2116–2134. doi:10.1080/08912963.2020.1772251. ISSN 0891-2963. S2CID 225710152.
  25. ^ Athanassiou, Athanassios; Herridge, Victoria; Reese, David S.; Iliopoulos, George; Roussiakis, Socrates; Mitsopoulou, Vassiliki; Tsiolakis, Efthymios; Theodorou, George (August 2015). "Cranial evidence for the presence of a second endemic elephant species on Cyprus". Quaternary International. 379: 47–57. Bibcode:2015QuInt.379...47A. doi:10.1016/j.quaint.2015.05.065. ISSN 1040-6182.
  26. ^ Athanassiou, Athanassios; van der Geer, Alexandra A.E.; Lyras, George A. (August 2019). "Pleistocene insular Proboscidea of the Eastern Mediterranean: A review and update". Quaternary Science Reviews. 218: 306–321. Bibcode:2019QSRv..218..306A. doi:10.1016/j.quascirev.2019.06.028. ISSN 0277-3791. S2CID 199107354.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Palaeoloxodon&oldid=1183966843"