Palaeoloxodon is an extinct genus of elephant. The genus originated in Africa during the Pliocene era, and expanded into Eurasia during the Pleistocene era. The genus contains some of the largest known species of elephants, over four metres tall at the shoulders, including the European straight-tusked elephant (Palaeoloxodon antiquus), and the southern Asian Palaeoloxodon namadicus, the latter of which was possibly the largest known land mammal based on fragmentary remains, but this requires proper reexamination. In contrast, the genus also contains many species of dwarf elephants that evolved via insular dwarfism on islands in the Mediterranean, some only a metre 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, circumscribed Palaeoloxodon as a subgenus of Loxodonta. It included the "E. antiquus—namadicus group", and he designated "E. namadicus naumanni Mak." as its type species. Palaeoloxodon was later thought to be a subgenus of Elephas, but this was abandoned by 2007. In 2016, a mitochondrial DNA sequence analysis of P. antiquus found that it was nested within the genus Loxodonta, more closely related African forest elephant, Loxodonta cyclotis, than the African bush elephant, Loxodonta africana. The authors suggested that this invalidated the genus Palaeoloxodon as currently recognized. A second study published in 2018 based on the nuclear genome suggested P. antiquus had a complex hybridization history, with over 60% of its DNA coming from a lineage closest to but outside the two extant Loxodonta species, around 6% from Mammuthus and 30% from a lineage closer to L. cyclotis than L. africana. The hybridisation probably took place in Africa, where Palaeoloxodon was dominant for most of the Pliocene and Early Pleistocene. Mainland species P. recki (Synonym:Elephas recki) (East Africa), the oldest (4.0 - 0.6 million years ago) and one of the largest species P. antiquus (Synonym:Elephas antiquus) (Straight tusked elephant) (Europe, Middle East, western Asia) ?P. huaihoensis (China) possibly synonymous with P. naumanni P. namadicus (Synonym:Elephas namadicus) (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), possible subspecies of E. namadicus ?P. turkmenicus known from a single specimen found in the Middle Pleistocene