''Cylindraspis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of recently

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

giant

tortoises Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a turtle shell, shell to protect from predation and other threats. The shell in tortoises is generally hard, ...

. All of its

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

lived in the

Mascarene Islands The Mascarene Islands (, ) or Mascarenes or Mascarenhas Archipelago is a group of islands in the Indian Ocean east of Madagascar consisting of the islands belonging to the Republic of Mauritius as well as the French department of Réunion. Thei ...

(

Mauritius Mauritius ( ; french: Maurice, link=no ; mfe, label=Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It incl ...

, Rodrigues and

Réunion Réunion (; french: La Réunion, ; previously ''Île Bourbon''; rcf, label= Reunionese Creole, La Rényon) is an island in the Indian Ocean that is an overseas department and region of France. It is located approximately east of the island ...

) in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

and all are now extinct due to hunting and introduction of non-native

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

They are not closely related to any extant group of tortoises, having diverged from the largely African clade including ''

Chelonoidis ''Chelonoidis'' is a genus of turtles in the tortoise family erected by Leopold Fitzinger in 1835. They are found in South America and the Galápagos Islands, and formerly had a wide distribution in the West Indies. The multiple subspecies of t ...

'', ''

Geochelone ''Geochelone'' is a genus of tortoises. ''Geochelone'' tortoises, which are also known as typical tortoises or terrestrial turtles, can be found in southern Asia. They primarily eat plants. Species The genus consists of two extant species: A ...

'', and ''

Astrochelys ''Astrochelys'' is a genus of tortoises in the family Testudinidae. The two species are both found in Madagascar, and both classified as critically endangered on the IUCN Red List The International Union for Conservation of Nature (IUCN) R ...

'' around 40 million years ago during the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

, most likely in Africa. The split between species within the genus is also deep, with the split between '' C. triserrata'' and all other members of the genus being estimated at around 28 million years ago, during the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

, before the current Mascarene Islands were even formed, meaning that the genus must have colonised the Mascarenes by

island hopping Leapfrogging, also known as island hopping, was a military strategy employed by the Allies in the Pacific War against the Empire of Japan during World War II. The key idea is to bypass heavily fortified enemy islands instead of trying to captu ...

from now submerged paleoislands formed by the

Réunion hotspot The Réunion hotspot is a volcanic hotspot which currently lies under the island of Réunion in the Indian Ocean. The Chagos-Laccadive Ridge and the southern part of the Mascarene Plateau are volcanic traces of the Réunion hotspot. The hotspo ...

as part of the

Mascarene Plateau The Mascarene Plateau is a submarine plateau in the Indian Ocean, north and east of Madagascar. The plateau extends approximately , from Seychelles in the north to Réunion in the south. The plateau covers an area of over of shallow water, wi ...

, including the

Saya de Malha Bank The Saya de Malha Bank (also the Sahia de Malha Bank, modern Portuguese: ''saia de malha'', English: ''mesh skirt'') or Mesh Skirt Bank, is one of the largest submerged ocean banks in the world, a part of the vast undersea Mascarene Plateau. ...

and

Nazareth Bank Nazareth Bank is a large submerged bank in the Indian Ocean. Geography It lies about 1,040 km east of northern Madagascar and 280 km south of the Saya de Malha Bank. The closest land is Cargados Carajos shoals, a small and remote dependency of ...

. Human settlers colonised the Mascarenes in 1663. These giant tortoises were very large and slow, thus making them easy game. Like many island species, they were also reported to have been friendly and unafraid of humans. Most species of this genus were already driven to

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

by 1795 and the last individuals were reputed to have died around 1840 (Arnold 1979, Bour 1980, Cheke and Hume 2008).

Species

The genus contains at least the following species: * †''C. indica'',

Réunion giant tortoise The Reunion giant tortoise (''Cylindraspis indica'') is an extinct species of giant tortoise in the family Testudinidae. It was endemic to Réunion Island in the Indian Ocean. This giant tortoise was numerous in the 17th and early 18th centu ...

, also known by the synonym ''Cylindraspis borbonica'', from Réunion * †''C. inepta'', saddle-backed Mauritius giant tortoise, from Mauritius * †''C. peltastes'',

domed Rodrigues giant tortoise The domed Rodrigues giant tortoise (''Cylindraspis peltastes'') is an extinct species of giant tortoise in the family Testudinidae. It was endemic to Rodrigues. It appears to have become extinct around 1800, as a result of human exploitation ...

, from Rodrigues * †''C. triserrata'',

domed Mauritius giant tortoise The domed Mauritius giant tortoise (''Cylindraspis triserrata'') is an extinct species of giant tortoise. It was endemic to Mauritius. Description One of two different giant tortoise species which were endemic to Mauritius, this domed species s ...

, from Mauritius * †''C. vosmaeri'',

saddle-backed Rodrigues giant tortoise The saddle-backed Rodrigues giant tortoise (''Cylindraspis vosmaeri)'' is an extinct species of giant tortoise in the family Testudinidae. The species was endemic to Rodrigues. Human exploitation caused the extinction of this species around 180 ...

, from Rodrigues File:Cylindraspis indica 1792.png, ''Cylindraspis indica'' File:Cylindraspis peltastes 1770.png, ''C. peltastes'' File:Cylindraspis vosmaeri 1792.png, ''C. vosmaeri''

References

* Arnold, E.N. 1979. Indian Ocean giant tortoises: their systematics and island adaptations. Philosophical Transactions of the Royal Society of London B Biological Sciences 286 (1011): 127-145 * Austin, J.J., Arnold, E.N. (2001). Ancient mitochondrial DNA and morphology elucidate an extinct island radiation of Indian Ocean giant tortoises (Cylindraspis). Proceedings: Biological Sciences, Volume 268, Number 1485, Pages: 2515–2523. * Bour, R. 1980. Systematique des tortues terrestres des iles Mascareignes: genre Cylindraspis Fitzinger, 1835 (Reptilia, Chelonii). Bulletin Du Museum National D'histoire Naturelle Section a Zoologie Biologie Et Ecologie Animales 2 (3): 895-904 * Bour, R. 1984. Les tortues terrestres geantes des iles de l'ocean Indien occidental. Studia Geologica Salamanticensia 1; 17-76 * Cheke, A., Hume, J. (2008). Lost Land of the Dodo, An Ecological History of Mauritius, Réunion & Rordrigues. T & AD Poyser, London. * Gerlach, J. 2004. Giant tortoises of the Indian Ocean. The genus Dipsochelys inhabiting the Seychelles Islands and the extinct giants of Madagascar and the Mascarenes. Edition Chimaira, Frankfurt, 208 pp. * Gerlach, J. & Canning, K.L. 1997. Evolution and history of the giant tortoises of the Aldabra island group. Testudo 4(3); 33-40 {{Testudinidae Fauna of the Mascarene Islands Holocene extinctions Turtle genera Extinct turtles Taxa named by Leopold Fitzinger Taxonomy articles created by Polbot