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).

Taxonomy
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  or P''. ex gr. ''mnaidriensis.  They descended from a colonisation of Sicily by the straight-tusked elephant (P. antiquus) during the late Middle Pleistocene, around 200,000 years ago, 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. 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.

Description
P. mnaidriensis has nearly 90% body reduction compared to the ancestral form with an estimated shoulder height of about 1.8 m and a mean body weight of about 1100 kg. Another estimate gives a shoulder height of 2 m and a weight of 1.7 MT. Like P. antiquus the head has a well developed parieto-occipital crest at the top of the skull. 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.

Ecology
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 (Panthera spelaea), cave hyenas (Crocuta crocuta spelaea) brown bears, wolves and red foxes) and large herbivores (wild boar, red deer, fallow deer, steppe bison, aurochs 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).

Extinction
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 m, somewhat smaller than other described individuals of P. cf./ ex gr. mnaidriensis.