A number of tortoise species have been recently removed from the genus. This taxon as formerly defined was "polyphyletic, representing at least five independent clades".[1] Tortoises removed include members of Aldabrachelys (from the Seychelles and Madagascar), Astrochelys[2] (Madagascar), Chelonoidis (South America and the Galápagos Islands), Stigmochelys[2] and Centrochelys (Africa), and the extinctMegalochelys (southern Asia).
These species are also unique for their ability to remember patterns and spatial pathways. Similar to mammals, these tortoises can remember directions and pathways by remembering the correct pathways in their long-term memory.[3]
^ abFritz, U.; Bininda-Emonds, O. R. P. (2007-07-03). "When genes meet nomenclature: Tortoise phylogeny and the shifting generic concepts of Testudo and Geochelone". Zoology. 110 (4). Elsevier: 298–307. doi:10.1016/j.zool.2007.02.003. PMID17611092.
^Wilkinson, A., Chan, H. M., & Hall, G. (2007). Spatial learning and memory in the tortoise (Geochelone carbonaria). Journal of Comparative Psychology, 121(4), 412.
