Stegodon is an extinct genus of proboscidean, related to elephants. It was originally assigned to the family Elephantidae along with modern elephants but is now placed in the extinct family Stegodontidae. Like elephants, Stegodon had teeth with plate-like lophs that are different from those of more primitive proboscideans like gomphotheres and mammutids. The oldest fossils of the genus are found in Late Miocene strata in Asia, likely originating from the more archaic Stegolophodon, subsequently migrating into Africa. While the genus became extinct in Africa during the Pliocene, Stegodon remained widespread in South, Southeast and East Asia until the end of the Pleistocene.
Dwarf elephants are prehistoric members of the order Proboscidea which, through the process of allopatric speciation on islands, evolved much smaller body sizes in comparison with their immediate ancestors. Dwarf elephants are an example of insular dwarfism, the phenomenon whereby large terrestrial vertebrates that colonize islands evolve dwarf forms, a phenomenon attributed to adaptation to resource-poor environments and lack of predation and competition.
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing. This process has occurred many times throughout evolutionary history, with examples including various species of dwarf elephants that evolved during the Pleistocene epoch, as well as more ancient examples, such as the dinosaurs Europasaurus and Magyarosaurus. This process, and other "island genetics" artifacts, can occur not only on islands, but also in other situations where an ecosystem is isolated from external resources and breeding. This can include caves, desert oases, isolated valleys and isolated mountains. Insular dwarfism is one aspect of the more general "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies. This is itself one aspect of island syndrome, which describes the differences in morphology, ecology, physiology and behaviour of insular species compared to their continental counterparts.
The Cypriot mouse is a species of mouse endemic to Cyprus. Its primary habitat seems to be the vineyards and fields of the Troödos Mountains region.
The Sardinian dhole is an extinct insular canid which was endemic to what is now the Mediterranean islands of Sardinia and Corsica during the Middle-Late Pleistocene. It went extinct at the end of the Pleistocene around the time of human settlement of the islands.
Candiacervus is an extinct genus of deer native to Pleistocene Crete. Due to a lack of other herbivores, the genus underwent an adaptive radiation, filling niches occupied by other taxa on the mainland. Due to the small size of Crete, some species underwent insular dwarfism, the smallest species, C. ropalophorus, stood about 40 centimetres (16 in) at the shoulders when fully grown, while other species were relatively large and comparable in size to mainland deer species. Some species are noted for their peculiar, elongate club-shaped antlers, though other species have more normal antlers.
The Cypriot pygmy hippopotamus is an extinct species of dwarf hippopotamus that inhabited the island of Cyprus from the Pleistocene until the early Holocene.
Hippopotamus pentlandi is an extinct species of hippopotamus from Sicily, known from the late Middle Pleistocene to early Late Pleistocene. It is the largest of the insular dwarf hippos known from the Pleistocene of the Mediterranean, "at most 20% smaller than the mainland forms", with an estimated body mass of approximately 1100 kg. It is suggested that it arrived in Sicily between 250,000 and 150,000 years ago, probably descending from the modern hippopotamus, with an origin from Hippopotamus antiquus being less likely. In comparison to those species, the muzzle was shorter, the occipital and nasal regions were more developed, the mastoid process was enlarged, and the dental row was shortened, and the condyle of the mandible is low. In comparison to H. amphibius, the orbits are also elevated. It was present in Sicily until at least the latest Middle Pleistocene around 120 kya, and was probably extinct by the beginning of Marine Isotope Stage 4. Contemporaneous species include the dwarf elephant Palaeoloxodon mnaidriensis, the aurochs, red deer, steppe bison, fallow deer, wild boar, brown bear, wolves, red foxes, cave hyena and cave lions. Its diet was likely grazing dominated, similar to that of modern H. amphibius. It is probably ancestral to Hippopotamus melitensis from Malta, which is substantially smaller than H. pentlandi.
Palaeoloxodon cypriotes is an extinct species of dwarf elephant that inhabited the island of Cyprus during the Late Pleistocene. The species became extinct around 12,000 years ago, around the time humans first colonised Cyprus.
Hoplitomeryx is a genus of extinct deer-like ruminants which lived on the former Gargano Island during the Miocene and the Early Pliocene, now a peninsula on the east coast of South Italy. Hoplitomeryx, also known as "prongdeer", had five horns and sabre-like upper canines similar to a modern musk deer.
Hippopotamus creutzburgi, the Cretan dwarf hippopotamus, is an extinct species of hippopotamus from the island of Crete. It lived on the island from the Early Pleistocene to early Middle Pleistocene, and probably descended from Hippopotamus antiquus. It was considerably smaller than H. antiquus, weighing approximately 400 kilograms (880 lb). It was one of only two large herbivores on the island during its existence, alongside the dwarf mammoth Mammuthus creticus, with large predators being absent, the only other species of mammal present on the island being the giant rat Kritimys. It is known from abundant remains collected from the Katharo basin in the eastern uplands of Crete, approximately 1,100–1,200 metres (3,600–3,900 ft) above sea level, as well as much rarer remains found in coastal caves. Analysis of its limbs suggests that it was more adapted to terrestrial locomotion than living hippopotamus, primarily walking on its hooves rather than its footpads as in living hippopotamus, and capable of traversing the rugged terrain of Crete. Analysis of its teeth suggests that it had a grazing diet, similar to modern Hippopotamus amphibius. The previous suggestion that the species can be divided into two subspecies is not supported by modern research.
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.
Hippopotamus laloumena is an extinct species of hippopotamus from Pleistocene and Holocene Madagascar, making it the oldest of Malagasy hippopotamus. H. laloumena was much larger than other Malagasy hippopotamus, but was still somewhat smaller than the common hippopotamus. However, little is known about the species because it was identified with only a lower jaw and limb bones. It was described in 1990 by French palaeontologists M. Faure and Guerin, the fossils recovered from a site near Mananjary on the east coast of Madagascar. The species name derives from Malagasy laloumena "hippopotamus".
Palaeoloxodon creutzburgi is an extinct species of elephant known from the Middle-Late Pleistocene of Crete. It is a descendant of the large mainland species Palaeoloxodon antiquus. It is known from localities across the island. P. chaniensis from Stylos and in Vamos cave, Chania, west Crete is considered to be a junior synonym of P. creutzburgi. It had undergone insular dwarfism, being approximately 40% of the size of its mainland ancestor, and was around the size of the living Asian elephant. It lived alongside the radiation of Candiacervus deer endemic to the island, the mouse Mus batae-minotaurus, the Cretan otter, and the Cretan shrew.
Mammuthus creticus, or the Cretan dwarf mammoth, is an extinct species of dwarf mammoth endemic to Crete during the Early Pleistocene to early Middle Pleistocene.
Rhagamys is an extinct genus of rodents in the subfamily Murinae, the Old World mice and rats. The genus was established by the Swiss zoologist Charles Immanuel Forsyth Major to accommodate Rhagamys orthodon, which is the only species in the genus. It was endemic to the Mediterranean islands of Corsica and Sardinia, descending from Rhagapodemus, which had colonised the islands around 3.6 million years ago. Its closest living relatives are of the genus Apodemus, which includes the field and wood mice.
Elephas beyeri is an extinct species of dwarf elephant known from the Middle Pleistocene. It was named after the anthropologist H. Otley Beyer. The type specimen, a partial molar tooth, was discovered on Cabarruyan Island in the Philippines but has since been lost.
Mececyon trinilensis, the Trinil dog, is an extinct canid species that lived on the island of Java in Indonesia during the Pleistocene.
Enhydrictis is a genus of extinct mustelid, belonging to the subfamily Galictinae. The type species, and best known, is Enhydrictis galictoides from the Pleistocene of Sardinia and Corsica. Some authors attribute species from mainland Eurasia to the genus, but this is disputed, with others considering the genus endemic to Sardinia-Corsica.
Mus minotaurus is an extinct species of mouse native to Crete during the Late Pleistocene-Holocene. It descended from a Mus musculus -like ancestor that arrived on Crete during the late Middle Pleistocene, replacing Kritimys, a large rat-like rodent that inhabited Crete during the Early and Middle Pleistocene. Both Kritimys and the ancestor of Mus minotaurus, Mus bateae are found together in Stavrós Cave. The Mus batae-minotaurus lineage shows a tendency to increase in size with time, an example of island gigantism, with Mus minotaurus being one of the largest known members of the genus Mus, with a body mass of approximately 54 grams, over 3 times the size of its mainland ancestor. It was likely heavily predated upon by the extinct endemic Cretan owl, as evidenced by the abundance of its remains found in owl pellets. It inhabited the island alongside a species of elephant, the radiation of endemic Candiacervus deer, the Cretan otter, and the Cretan shrew. Mus minotaurus became extinct sometime during the Holocene epoch, with its remains apparently being found in Neolithic and early Bronze Age sites on the island. Its extinction may have been due to competition with the closely related house mouse introduced to the island by humans during the early Bronze Age.
