''Cylindraspis'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of recently

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

giant

tortoises Tortoises ( ) are reptiles of the family Testudinidae of the order Testudines (Latin for "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 A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 islands belonging to the Republic of Mauritius as well as the French department of Réunion. Their na ...

(

Mauritius Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Ag ...

Rodrigues Rodrigues ( ; Mauritian Creole, Creole: ) is a Autonomous administrative division, autonomous Outer islands of Mauritius, outer island of the Republic of Mauritius in the Indian Ocean, about east of Mauritius. It is part of the Mascarene Isl ...

and

Réunion Réunion (; ; ; known as before 1848) is an island in the Indian Ocean that is an overseas departments and regions of France, overseas department and region of France. Part of the Mascarene Islands, it is located approximately east of the isl ...

) in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

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

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

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

Geochelone ''Geochelone'', from Ancient Greek γῆ (''gê''), meaning "earth", and χελώνη (''khelṓnē''), meaning "turtle", is a genus of tortoises. ''Geochelone'' tortoises, which are also known as typical tortoises or terrestrial turtles, can be ...

'', and '' Astrochelys'' around 40 million years ago during the

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

, 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 (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

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

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 an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce 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, also known by the synonym ''Cylindraspis borbonica'', from Réunion * †''C. inepta'', saddle-backed Mauritius giant tortoise, from Mauritius * †''C. peltastes'', domed Rodrigues giant tortoise, from Rodrigues * †''C. triserrata'', domed Mauritius giant tortoise, from Mauritius * †''C. vosmaeri'', saddle-backed Rodrigues giant tortoise, 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 {{Taxonbar, from=Q135344 Fauna of the Mascarene Islands Holocene extinctions Turtle genera Extinct turtles Taxa named by Leopold Fitzinger Taxonomy articles created by Polbot