Palaeoloxodon mnaidriensis

Palaeoloxodon mnaidriensis is an extinct species of dwarf elephant belonging to the genus Palaeoloxodon, native to the Siculo-Maltese archipelago during the late Middle Pleistocene and Late Pleistocene. It is derived from the European mainland straight-tusked elephant (Palaeoloxodon antiquus).[2]

Palaeoloxodon mnaidriensis
Temporal range: late Middle-Late Pleistocene 0.2–0.02 Ma
Skeleton in Palermo, Sicily
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Family: Elephantidae
Genus: Palaeoloxodon
Species:
P. mnaidriensis
Binomial name
Palaeoloxodon mnaidriensis
(Adams, 1874)[1]

Taxonomy and evolution

edit

While previously thought to have inhabited both Malta and Sicily. P. mnaidriensis technically only represents the Maltese species, with remains from Sicily belonging to a separate species, provisionally referred to as P. cf. mnaidriensis[3] or P. ex gr. mnaidriensis.[4] They descended from a colonisation of Sicily by the straight-tusked elephant (P. antiquus) during the late Middle Pleistocene, around 200,000 years ago,[3] which replaced the even smaller one-metre-tall Palaeoloxodon falconeri, which had descended from a separate colonisation of Sicily by P. antiquus several hundred thousand years prior.[5] The elephant species native to Malta and Sicily had reduced in body size as a result of insular dwarfism, a common phenomenon resulting from the colonisation of islands by large mammals. The much smaller body size of P. mnaidriensis compared to P. antiquus, in combination with the relatively short period of time between colonisation and small body size suggests that the rate of dwarfism was relatively rapid.[3]

Description

edit

P. mnaidriensis has nearly 90% body reduction compared to the ancestral form with an estimated shoulder height of about 1.8 metres (5.9 ft) and a mean body weight of about 1,100 kilograms (2,400 lb).[2] Another estimate gives a shoulder height of 2 m (6.6 ft) and a weight of 1.7 t (1.9 short tons).[6] Like P. antiquus the head has a well developed parieto-occipital crest at the top of the skull.[7] The teeth are around 30% the size of those of P. antiquus. Relative to P. antiquus, the enamel of the teeth is thicker, and the density of lamellae on the teeth is higher, with the number of plates being slightly lower than those of the molars of P. antiquus. The limb bones are proportionally more robust than those of P. antiquus.[2]

Ecology

edit

The appearance of P. cf. mnaidriensis on Sicily marks a faunal turnover where the depauperate endemic fauna that characterised Sicily during the Early and early mid-Middle Pleistocene was profoundly altered by the arrival of some large mammals from the continental fauna of mainland Italy, including both predators (cave lions, cave hyenas, brown bears, wolves and red foxes) and large herbivores (wild boar, red deer, fallow deer, steppe bison, aurochs, European wild ass, and the hippo Hippopotamus pentlandi) which coexisted with P. cf. mnaidriensis. The larger body size of P. cf. mnaidriensis in comparison to P. falconeri is suggested to be as a result of needing to defend against predators, as well as due to the presence of other competing herbivores. On Malta, the only other large mammal present aside from P. mnaidriensis was the dwarf hippopotamus Hippopotamus melitensis. Its ecology has been suggested to have been that of a mixed feeder (both grazing and browsing).[5][8][9][10]

Extinction

edit

The youngest records of P. cf./ ex gr. mnaidriensis are from what is now the island of Favignana off the coast of western Sicily dating to around 20,000 years ago, during the Last Glacial Maximum (though this date is likely to be a minimum age), which was connected to mainland Sicily for most of the Last Glacial Period due to lowered sea levels, as well as San Teodoro Cave in northeast Sicily, which dates to sometime after 32,000 years ago. These individuals are estimated to have had a shoulder height of roughly 1.5 metres (4.9 ft), somewhat smaller than other described individuals of P. cf./ ex gr. mnaidriensis.[4]

See also

edit

References

edit
  1. ^ Adams, A. Leith (November 1874). "I. On the Dentition and Osteology of the Maltese fossil Elephants, being a Description of Remains discovered by the Author in Malta, between the years 1860 and 1866". The Transactions of the Zoological Society of London. 9 (1): 1–124. doi:10.1111/j.1096-3642.1874.tb00235.x.
  2. ^ a b c Ferretti, M.P. (May 2008). "The dwarf elephant Palaeoloxodon mnaidriensis from Puntali Cave, Carini (Sicily; late Middle Pleistocene): Anatomy, systematics and phylogenetic relationships". Quaternary International. 182 (1): 90–108. Bibcode:2008QuInt.182...90F. doi:10.1016/j.quaint.2007.11.003.
  3. ^ a b c Baleka, Sina; Herridge, Victoria L.; Catalano, Giulio; Lister, Adrian M.; Dickinson, Marc R.; Di Patti, Carolina; Barlow, Axel; Penkman, Kirsty E.H.; Hofreiter, Michael; Paijmans, Johanna L.A. (August 2021). "Estimating the dwarfing rate of an extinct Sicilian elephant". Current Biology. 31 (16): 3606–3612.e7. Bibcode:2021CBio...31E3606B. doi:10.1016/j.cub.2021.05.037. PMID 34146486. S2CID 235477150.
  4. ^ a b 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. Bibcode:2021HBio...33.2116P. doi:10.1080/08912963.2020.1772251. ISSN 0891-2963. S2CID 225710152.
  5. ^ a b Scarborough, Matthew Edward (March 2022). "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. hdl:11427/36354. ISSN 2571-550X.
  6. ^ Larramendi, A. (2016). "Shoulder height, body mass and shape of proboscideans". Acta Palaeontologica Polonica. 61. doi:10.4202/app.00136.2014. S2CID 2092950.
  7. ^ 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.
  8. ^ Bonfiglio, L., Marra, A. C., Masini, F., Pavia, M., & Petruso, D. (2002). Pleistocene faunas of Sicily: a review. In W. H. Waldren, & J. A. Ensenyat (Eds.), World islands in prehistory: international insular investigations. British Archaeological Reports, International Series, 1095, 428–436.
  9. ^ Bethune, Elehna; Kaiser, Thomas M.; Schulz-Kornas, Ellen; Winkler, Daniela E. (November 2019). "Multiproxy dietary trait reconstruction in Pleistocene Hippopotamidae from the Mediterranean islands". Palaeogeography, Palaeoclimatology, Palaeoecology. 533: 109210. Bibcode:2019PPP...53309210B. doi:10.1016/j.palaeo.2019.05.032. S2CID 181824675.
  10. ^ van der Geer, Alexandra A. E.; van den Bergh, Gerrit D.; Lyras, George A.; Prasetyo, Unggul W.; Due, Rokus Awe; Setiyabudi, Erick; Drinia, Hara (August 2016). "The effect of area and isolation on insular dwarf proboscideans". Journal of Biogeography. 43 (8): 1656–1666. Bibcode:2016JBiog..43.1656V. doi:10.1111/jbi.12743. ISSN 0305-0270.