Aldabrachelys grandidieri

Superregnum: Eukaryota
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Cladus: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Cladus: Archelosauria
Division: Pan-Testudines
Division: Testudinata
Ordo: Testudines
Subordo: Cryptodira
Superfamilia: Testudinoidea

Familia: Testudinidae
Genus: Aldabrachelys
Species: †

Aldabrachelys grandidieri

Name

†

Aldabrachelys grandidieri (Vaillant 1868:378)

Lectotype: MNHN-P MAD3501 (Bour 1994)
Type locality: Etseré, Madagascar, Late Holocene

Synonymy

Emys gigantea Grandidier 1868:378
Testudo grandidieri Vaillant 1885:876 (nomen novum)
Testudo madagascariensis Rothschild 1915
Geochelone grandidieri Loveridge & Williams 1957:224
Aldabrachelys grandidieri Bour 1980:544
Dipsochelys grandidieri Bour 1982:118
Aldabrachelys grandidieri Fritz & Havas 2007:267

References

Vaillant, M.L. 1885. Remarques complémentaires sur les tortues gigantesques de Madagascar. Comptes Rendus Hebd. Séanc. Adad. Sc. Paris 100:874-877
Bour,R. 1980. Essai sur la taxinomie des Testudinidae actuels (Reptilia, Chelonii). Bull. Mus. natl. Hist. nat. Paris (4)2(2):541-546
Turtle Extinctions Working Group (Rhodin, A.G.J., Thomson, S., Georgalis, G., Karl, H.-V., Danilov, I.G., Takahashi, A., de la Fuente, M.S., Bourque, J.R., Delfino, M., Bour, R., Iverson, J.B., Shaffer, H.B., and van Dijk, P.P.). 2015. Turtles and tortoises of the world during the rise and global spread of humanity: first checklist and review of extinct Pleistocene and Holocene chelonians. Chelonian Research Monographs. 5(8):000e.1–66. Download

Aldabrachelys grandidieri, or Grandidier's giant tortoise, is an extinct species of tortoise that was endemic to Madagascar. Mitochondrial DNA extracted from subfossil bone confirm that it is a distinct species.[1][2]

Description
Underside of carapace

Aldabrachelys grandidieri was a giant tortoise, one of the largest in the world, measuring about 125 cm (49 in) in carapace length. It was originally one of the six endemic tortoise species of Madagascar (two large Aldabrachelys; two medium Astrochelys; two small Pyxis).

It is distinguished from all other Aldabrachelys by a massive, flattened or depressed carapace, bulging sides of the carapace, short gulars, top of the nasal aperture is higher than the top of orbits, diverging quadrates, broad postorbitals, and a very large processus vomerinus dorsalis. It also had an unusually thick, strong carapace, possibly an adaptation to heavy predation. It seems to have been predominantly a grazer of meadows and wetlands.[1]
Extinction

Material of this species has been dated to 1250–2290 years before present. It seems to have gone extinct relatively soon after the later migration of humans arrived from the mainland of Africa. Unlike its more common sister species, the abrupt giant tortoise (Aldabrachelys abrupta (also extinct)), the massive grandidieri did not seem to have succeeded in coexisting with humans for any length of time.[1][2]
Ecology

Aldabrachelys grandidieri (along with Aldabrachelys abrupta) likely were seed dispersers of the six baobab (Adansonia spp.) species endemic to Madagascar; in an experiment, extant Aldabra giant tortoises (Aldabrachelys gigantea) readily consumed fruit of Adansonia rubrostipa.[3] Other ecological functions of giant tortoises likely included trampling and selectively consuming vegetation. It is suggested that introduced Aldabra giant tortoises could be used for restoration of these functions.[4]
References

Aldabrachelys grandidieri at the Reptarium.cz Reptile Database. Accessed 16 May 2015.
Austin, J. J.; Arnold, E. N.; Bour, R. (2003). "Was there a second adaptive radiation of giant tortoises in the Indian Ocean? Using mitochondrial DNA to investigate speciation and biogeography of Aldabrachelys (Reptilia, Testudinidae)". Molecular Ecology. 12 (6): 1415–1424. doi:10.1046/j.1365-294X.2003.01842.x. PMID 12755871.
Andriantsaralaza, S.; Pedrono, M.; Tassin, J.; Roger, E.; Rakouth, B.; Danthu, P. (2014). "The role of extinct giant tortoises in the germination of extant baobab Adansonia rubrostipa seeds in Madagascar" (PDF). African Journal of Ecology. 52 (2): 246–249. doi:10.1111/aje.12101.
Pedrono, M.; Griffiths, O. L.; Clausen, A.; Smith, L. L.; Griffiths, C. J.; Wilmé, L.; Burney, D. A. (2013). "Using a surviving lineage of Madagascar's vanished megafauna for ecological restoration". Biological Conservation. 159: 501–506. doi:10.1016/j.biocon.2012.11.027.