Turtles, tortoises, and terrapins are ectothermic reptiles, most of whose body is shielded by a special bony or cartilagenous shell developed from their ribs. They belong to an anapsid lineage, as can be seen from their solid skullcap. About 300 species are alive today; some are highly endangered.
The order to which the turtles belong is usually called Testudines. Sometimes Chelonia is given as a junior synonym, but this might strictly speaking b...
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Turtles, tortoises, and terrapins are ectothermic reptiles, most of whose body is shielded by a special bony or cartilagenous shell developed from their ribs. They belong to an anapsid lineage, as can be seen from their solid skullcap. About 300 species are alive today; some are highly endangered.
The order to which the turtles belong is usually called Testudines. Sometimes Chelonia is given as a junior synonym, but this might strictly speaking be incorrect. For most purposes, the differences are minor however: The Chelonia are simply the Testudines plus the "proto-turtle" Australochelys africanus, a turtlelike anapsid from the Jurassic which lacked some of the Testudines' apomorphies but is overall of very uncertain placement due to the lack of material. If Murrhardtia staeschei (known from a rather complete shell) and Palaeochersis talampayensis are close relatives of Australochelys, the Chelonia and Testudines are indeed likely to be effectively synonymous in content – though the...
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