Candiacervus Temporal range: late Middle - Late Pleistocene | |
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Specimen of Candiacervus sp. II | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Artiodactyla |
Family: | Cervidae |
Genus: | † Candiacervus Kuss, 1975 |
Species | |
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Candiacervus is an extinct genus of deer native to Pleistocene Crete. [1] 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, [2] the smallest species, C. ropalophorus, stood about 40 centimetres (16 in) at the shoulders when fully grown, [3] while other species were relatively large and comparable in size to mainland deer species. Some species (C. ropalophorus) are noted for their peculiar, elongate club-shaped antlers, though other species have more normal antlers.
The Cretan deer is a typical example of taxonomical problems involving endemic insular mammals, due to the much larger variety than on the mainland, and the strong endemism. This obscures taxonomy, because many endemic features of Candiacervus are not unique but are found in other island deer as well, [4] such as Cervus astylodon (Ryukyu Islands) and Hoplitomeryx (Southern Italy). De Vos (1979, 1984, 1996) [5] [6] [7] identified eight morphotypes into one genus (Candiacervus), whereas Capasso Barbato (1992) [8] included the larger species, rethymnensis, major and dorothensis, in Cervus (subgenus Leptocervus) and the smaller species ropalophorus and cretensis in Megaloceros (subgenus Candiacervus), implying two different ancestors, and she also did not recognize sp. II with its three morphotypes, instead referring it to ropalophorus. A new paper published in 2018 rejected the conclusion of Capasso Barbato (1992) and formally named the three morphotypes of De Vos' Candiacervus sp. II C. devosi, C. listeri, and C. reumeri. [9]
On the nearby island of Karpathos, Kuss [10] found deer which were, in his view, similar to the Cretan deer. Therefore, he grouped his species pygadiensis and cerigensis under the genus Candiacervus, but this needs further confirmation. As long as no direct link with Crete is attested, the deer genus of Karpathos is questioned, and better referred to as Cervus.
They were traditionally considered to be related to the giant Irish elk (Megaloceros giganteus) with some experts regarding Candiacervus as a subgenus of Megaloceros . [8] However, van der Geer (2018) finds them closer to fallow deer (Dama), [9] while Croitor has suggested that the genus is closely related to the giant deer genus Praemegaceros . [11]
The Cretan deer is represented by no less than eight different morphotypes, ranging from dwarf size with withers height of about 40 centimetres (16 in) to very large with withers height of about 165 centimetres (65 in), [6] spanning a body mass range from 27.8 kilograms (61 lb) in the smallest species C. ropalophorus to 245.4 kilograms (541 lb) in the largest species C. major. This is explained as an adaptive radiation following ecological release to occupy available niches. The larger species had proportionally longer legs than mainland deer, while the dwarf species had proportionally shorter legs. [12] The large size of the only known individual of C. major may be due to pituitary gigantism, in which case the species may be a synonym of one of the smaller species, perhaps the red deer sized C. dorothensis, [13] which is suggested to weigh around 170.1 kilograms (375 lb). [12] The short legs of the dwarf species is suggested to be an adaptation to a goat-like niche of climbing around on rocky terrain and consuming low quality foliage. [14] The antler morphology was highly varied, in some of the dwarf species like C. ropalophorus, the antler was simplified and greatly elongated into a club like structure unique among deer, while others retained a more typical antler morphology. The club-like antlers of C. ropalophorus and similar forms were probably only used for display rather than combat. [9] The antler and skull morphology is unknown in the largest species. [12]
The fauna of which Candiacervus is an element is called Biozone II, or the Mus Zone (after the Mus genus of mice). [15] This fauna inhabited Crete between the late Middle and Late Pleistocene, approximately 0.3 to 0.01 million years ago. It succeeds the Kritimys biozone, which spanned the Early to early Middle Pleistocene. [16]
The typical terrestrial mammalian fauna elements of this biozone aside from Candiacervus are a lineage of mice (Mus bateae, M. minotaurus ), a dwarf elephant ( Palaeoloxodon creutzburgi ), the Cretan otter (Lutrogale (Isolalutra) cretensis), and the Cretan shrew (Crocidura zimmermanni). [17]
Despite living in an environment free of large terrestrial predators, the species of Candiacervus exhibited relatively high rates of juvenile mortality, with likely causes of death being accidents and malnutrition. [18] The growth rate of the bones of dwarf Candiacervus was relatively slow compared to living deer. [19] Adult individuals are suggested to have had relatively long lifespans compared to extant ruminants of a similar body size, [19] [18] [20] with some individuals of dwarf Candiacervus reaching a lifespan of 18 years. [19]
The extinction of Candiacervus may be due to the arrival of humans at the end of the Pleistocene. [21] They could have exterminated the deer either actively by hunting, or passively by destroying its habitat. Another option is a gradual depletion of the ecosystem, as indicated by the finding of a complete herd consisting of individuals suffering a bone disease of an osteosclerotic nature. [22] The impact of paleolithic humans is at present still unproven, partly because of the scarcity on published fauna lists from archaeological sites (except for Knossos), partly because of the insecurely dated materials.
In 2018, it was proposed that Asphendou Cave petroglyphs in western Crete depicted Candiacervus, suggesting that humans and Candiacervus chronologically overlapped on the island. [23]
Megaloceros is an extinct genus of deer whose members lived throughout Eurasia from the Pleistocene to the early Holocene. The type and only undisputed member of the genus, Megaloceros giganteus, vernacularly known as the "Irish elk" or "giant deer", is also the best known. Fallow deer are thought to be their closest living relatives. Megaloceros has been suggested to be closely related to other genera of "giant deer", like the East Asian genus Sinomegaceros, and the European Praemegaceros.
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 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.
The Calamian deer, also known as Calamian hog deer, is an endangered species of deer found only in the Calamian Islands of Palawan province in the Philippines. It is one of three species of deer native to the Philippines, the other being the Philippine sambar and the Visayan spotted deer.
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.
The Cretan shrew is a species of mammal in the family Soricidae. It is endemic to the island of Crete, Greece. Its natural habitat is temperate shrubland, and the animal is threatened by habitat loss. It is found in the mountainous highlands of Crete, having been displaced from lower altitudes by the lesser white-toothed shrew.
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 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.
Megacyon merriami, or Merriam's dog, was a prehistoric canid that lived on the island of Java in Indonesia during the Early Pleistocene. Its scientific name means "Merriam's large dog".
Praemegaceros is an extinct genus of deer, known from the Pleistocene and Holocene of Western Eurasia. Praemegaceros is considered to be a genus of "giant deer", with many species having an estimated body mass of around 400 kilograms (880 lb), considerably larger than most living deer.
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.
Megaceroides algericus is an extinct species of deer known from the Late Pleistocene to the Holocene of North Africa. It is one of only two species of deer known to have been native to the African continent, alongside the Barbary stag, a subspecies of red deer. It is considered to be closely related to the giant deer species of Eurasia.
Kritimys, also known as the Cretan giant rat is an extinct genus of murid rodent that was endemic to the island of Crete during the Early and Middle Pleistocene. There are two known species, K. kiridus from the Early-Mid Pleistocene, and its descendant K. catreus from the Middle Pleistocene. It is suggested to be closely related to and probably derived from Praomys. As with most island rodents, Kritimys was larger than its mainland relatives, with its size increasing over time, with K. catreus estimated to weigh 518 grams (1.142 lb), around 6.7 times the weight of its mainland ancestor, an example of island gigantism. The temporal range of the genus is considered to define the regional Kritimys biozone, during which time there were only two other species of mammal native to the island, a species of dwarf mammoth, Mammuthus creticus and the dwarf hippopotamus Hippopotamus creutzburgi. It became extinct during the late Middle Pleistocene, following the arrival of the Mus bateae-minotaurus lineage to the island, exhibiting a decrease in size shortly before its extinction.
The Cretan otter(Lutrogale cretensis) is an extinct otter that was endemic to Crete during the Pleistocene.
Cervus astylodon, the Ryukyu dwarf deer, is an extinct species of dwarf deer that was endemic to the Ryukyu Islands of Okinawa, Ishigaki, Kume and Tokunoshima. It lived throughout the Pleistocene, becoming extinct towards the end of the Late Pleistocene, following the arrival of humans to the Ryukyu Islands.
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.