Leithia Temporal range: | |
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Skeleton of Lethia melitensis | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Gliridae |
Subfamily: | Leithiinae |
Genus: | † Leithia Lydekker, 1896 [1] |
Type species | |
†Myoxus melitensis | |
species | |
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Leithia is an extinct genus of giant dormice from the Pleistocene of the Mediterranean islands of Malta and Sicily. It is considered an example of island gigantism. Leithia melitensis is the largest known species of dormouse, living or extinct, being twice the size of any other known species.
The species were first named by Andrew Leith Adams in 1863 from remains found in caves in Malta and were assigned to the living genus Myoxus. [2] Leithia was proposed in 1896 by Richard Lydekker as a new genus, suggesting an arrangement currently recognised as the subfamily Leithiinae; the names honour Leith Adams. [1] [3] Two species of Leithia, namely Leithia melitensis and the smaller L. cartei, lived in Sicily and Malta. [4]
The skull of Leithia melitensis reached a length of approximately 7 centimetres (2.8 in), roughly twice the length of that of the garden dormouse (Eliomys quercinus). [5] L. melitensis reached a total size comparable to a cat [6] or a rabbit, [7] with an estimated body mass of approximately 1 kilogram (2.2 lb). [8] Compared to Eliomys, the skull morphology of L. melitensis is much more robust, particularly the zygomatic region (indicating the presence of large masseter muscles in life) and the pterygoid flange. The rostrum of L. melitensis relatively short, and the molar teeth are proportionally enlarged relative to Eliomys. [5] The mandible of L. melitensis is also extremely robust. [9]
The teeth of Leithia melitensis exhibit a variable amount of wear, indicating an abrasive, and probably largely herbivorous diet, [9] with the lower jaw exhibiting greater adaption to chewing rather than gnawing. [10] Leithia was likely predated upon by large birds of prey native to the islands, such as the endemic large barn-owl Tyto mourerchauvireae. [5]
The closest living relative of Leithia is assumed to be Eliomys , based on morphological similarities. [5] Remains tentively referred to Leithia are known from the Early Pleistocene (late Villafranchian) "Monte Pellegrino" faunal complex. [11] [12] However, other authors have suggested that this taxon is instead more closely related to the genus Maltamys , also endemic to Sicily and Malta. [13] It has been suggested by some that the ancestors Leithia arrived in Sicily during the Late Miocene (Messinian) or Pliocene, but this is not preserved in the fossil record. [11] [12] For most of the Middle Pleistocene during the "Elephas falconeri" faunal complex, Leithia was one of a small number of mammal species present on Sicily and Malta, alongside the dwarf elephant Palaeoloxodon falconeri, the large dormouse Maltamys, a shrew belonging to the genus Crocidura, and an otter. During the late Middle Pleistocene a faunal turnover event occurred, caused by the uplift of Calabria and Sicily resulting in a closer connection with the Italian mainland, which during episodes of low sea level allowed some large animals from the mainland fauna of Italy to invade Sicily. Leithia persisted alongside the new arrivals for some time as demonstrated by their co-occurrence in deposits assigned to the “ Elephas mnaidriensis ” faunal complex, but apparently became extinct sometime before the end of the Pleistocene, prior the deposition of deposits assigned to the “Grotta S. Teodoro Pianetti” faunal complex. [11] [12]
A dormouse is a rodent of the family Gliridae. Dormice are nocturnal animals found in Africa, Asia, and Europe. They are named for their long, dormant hibernation period of six months or longer.
Palaeoloxodon is an extinct genus of elephant. The genus originated in Africa during the Early Pleistocene, and expanded into Eurasia at the beginning of the Middle Pleistocene. The genus contains some of the largest known species of elephants, over 4 metres (13 ft) tall at the shoulders, including the African Palaeoloxodon recki, the European straight-tusked elephant and the South Asian Palaeoloxodon namadicus. P. namadicus has been suggested to be the largest known land mammal by some authors based on extrapolation from fragmentary remains, though these estimates are highly speculative. 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.
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. Some modern populations of Asian elephants have also undergone size reduction on islands to a lesser degree, resulting in populations of pygmy elephants.
The Europeanedible dormouse or European fat dormouse is a large dormouse and one of only two living species in the genus Glis, found in most of Europe and parts of western Asia. The common name comes from the Romans, who ate them as a delicacy.
Nuralagus is an extinct genus of leporid, with a single species, Nuralagus rex, described in 2011. It lived on Menorca, one of the Balearic Islands in the western Mediterranean during the Pliocene epoch. It is the largest known lagomorph to have ever existed, with an estimated weight of 8–12 kilograms (18–26 lb), nearly double the weight of the average Flemish Giant rabbit. It likely went extinct at the Pliocene-Pleistocene transition when Mallorca and Menorca were united as one island, letting the mammalian fauna of Mallorca, including the goat-like ungulate Myotragus, colonize Nuralagus's habitat.
Andrew Leith Adams FRSE, FRS was a Scottish army physician, naturalist and geologist. He collected and described specimens of birds and mammals, writing also about his travels in Asia and the middle east where he served at various times. He was married to the novelist Bertha Jane Grundy and was the father of the writer Francis Adams.
Palaeoloxodon falconeri is an extinct species of dwarf elephant from the Middle Pleistocene of Sicily and Malta. It is amongst the smallest of all dwarf elephants at only 1 metre (3.3 ft) in height. A member of the genus Palaeoloxodon, it derived from a population of the mainland European straight-tusked elephant.
Hippopotamus melitensis is an extinct hippopotamus from Malta. It lived during Middle-Late Pleistocene. It probably descended from Hippopotamus pentlandi from Sicily, which in turn probably descended from the common hippopotamus. Like Hippopotamus pentlandi, Hippopotamus melitensis is substantially smaller in size than H. amphibius as a result of insular dwarfism, having an estimated mass of approximately 900 kg, which is smaller than the 1100 kg estimated for H. pentlandi. The diet of H. melitensis is suggested to have been more generalist than Hippopotamus amphibius, likely as a result of limited resource diversity and lack of competition, as the only other large herbivore on the island was the dwarf elephant Palaeoloxodon mnaidriensis. The majority of findings of this species are from Għar Dalam, a cave on Malta famous for its Pleistocene fossil deposits.
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.
Leithiinae is a subfamily of dormice. It is named after the Leithia, an extinct genus of giant dormouse from the Pleistocene of Sicily.
Palaeoloxodon cypriotes is an extinct species of dwarf elephant that inhabited the island of Cyprus during the Late Pleistocene. Remains comprise 44 molars, found in the north of the island, seven molars discovered in the south-east, a single measurable femur and a single tusk among very sparse additional bone and tusk fragments. The molars support derivation from the large straight-tusked elephant (Palaeoloxodon antiquus). The species is presumably derived from the older, larger P. xylophagou from the late Middle Pleistocene which reached the island presumably during a Pleistocene glacial maximum when low sea levels allowed a low probability sea crossing between Cyprus and Asia Minor. During subsequent periods of isolation the population adapted within the evolutionary mechanisms of insular dwarfism, which the available sequence of molar fossils confirms to a certain extent. The fully developed Palaeoloxodon cypriotes weighed not more than 200 kg (440 lb) and had a height of around 1 m (3.28 ft). The species became extinct around 12,000 years ago, around the time humans first colonised Cyprus.
Xenocyon is an extinct group of canids, either considered a distinct genus or a subgenus of Canis. The group includes Canis (Xenocyon) africanus, Canis (Xenocyon) antonii and Canis (Xenocyon) falconeri that gave rise to Canis (Xenocyon) lycanoides. The hypercarnivorous Xenocyon is thought to be closely related and possibly ancestral to modern dhole and the African wild dog, as well as the insular Sardinian dhole.
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.
The fauna of Italy comprises all the animal species inhabiting the territory of the Italian Republic and its surrounding waters. Italy has probably the highest level of faunal biodiversity in Europe, with over 57,000 species recorded, representing more than a third of all European fauna. This is due to various factors. The Italian peninsula is in the centre of the Mediterranean Sea, forming a corridor between central Europe and North Africa, and it has 8,000 km (5,000 mi) of coastline. Italy also receives species from the Balkans, Eurasia, and the Middle East. Italy's varied geological structure, including the Alps and the Apennines, Central Italian woodlands, and Southern Italian Garigue and Maquis shrubland, also contribute to high climate and habitat diversity.
Hypnomys, otherwise known as Balearic giant dormice, is an extinct genus of dormouse (Gliridae) in the subfamily Leithiinae. Its species are considered examples of insular gigantism. They were endemic to the Balearic Islands in the western Mediterranean from the Early Pliocene until their extinction around 4,000 years ago. They first appeared in the fossil record on Mallorca during the Early Pliocene, presumably due to the Messinian salinity crisis causing a connection with mainland Europe. They later spread to Menorca, and a possible molar is also known from Ibiza. Hypnomys became extinct during the Holocene after human arrival on the Balearics. They were one of only three native land mammals to the islands at the time of human arrival, alongside the shrew Nesiotites and goat-antelope Myotragus.
Mammuthus creticus, or the Cretan dwarf mammoth, is an extinct species of dwarf mammoth endemic to Crete. It is only known from a single locality near Chania, which probably dates to the Early or Middle Pleistocene. With a shoulder height of about 1 metre (3.3 ft) and a weight of about 180 kilograms (400 lb), it was the smallest mammoth that ever existed. Its size reduction was the result of insular dwarfism, where the body size of large mammals on islands reduces as the result of decreased food availability, predation and competition. It was originally described as Elephas creticus by Dorothea Bate in 1907. After DNA research published in 2006, it was proposed to rename Elephas creticus into Mammuthus creticus. Others proposed to rename all the described specimens of larger size under the new subspecies name Elephas antiquus creutzburgi. A 2007 study criticised the results of the 2006 DNA study, showing that the DNA research was likely flawed. However, morphological data supports a placement in Mammuthus. It probably derived from Mammuthus meridionalis, or less likely, Mammuthus rumanus. It was one of only three mammal species native to Crete during the Early Pleistocene and the early Middle Pleistocene, alongside the dwarf hippopotamus Hippopotamus creutzburgi and the giant rat Kritimys.
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Microtus (Tyrrhenicola) henseli is an extinct species of vole belonging to the genus Microtus that was endemic to Sardinia and Corsica during the Pleistocene and Holocene.
Solitudo is an extinct genus of tortoise that was found during the Pliocene and Pleistocene on the Mediterranean islands of Menorca, Malta and Sicily. The genus includes three described species, Solitudo robusta, Solitudo gymnesica and Solitudo sicula as well as a likely fourth, undescribed species from Monte Pellegrino in Sicily. Solitudo sicula, the youngest of the species, died out approximately 12.5 thousand years BP. The largest species, Solitudo gymnesica, has been estimated to have reached a carapace length of 1.1–1.3 m (3.6–4.3 ft).