Testudinidae

Pair of male gopher tortoises Gopherus polyphemus duking it out, photographed by Daniel Parker.

Belongs within: Testudinoidae.
Contains: Testudininae.

The Testudinidae are the land tortoises, the most entirely terrestrial group of the Testudinata.

Synapomorphies (from Gaffney & Meylan 1988): Two or fewer phalanges in manus and pes; only four digits in pes; quadrate usually enclosing stapes; axillary and inguinal glands absent; slightly wide fissura ethmoidalis; cloacal bursae absent; coracoid blade wide; foramen nervi trigemini with maxillary aperture; trochanters of femur coalesced.

<==Testudinidae
    |  i. s.: Hadrianus Cope 1872 CP03, C76
    |           `--H. corsonii Leidy 1871 C76
    |--Manouria GM88
    |    |--M. emys CP03
    |    `--M. impressa CP03
    `--+--+--Hesperotestudo GM88
       |  `--Testudininae GM88
       `--Xerobatinae GM88
            |--Stylemys GM88
            `--+--Xerobates GM88
               `--Gopherus GM88
                    |--G. agassizii CP03
                    |--G. berlandieri CP03
                    `--G. polyphemus CP03

REFERENCES

[CP03] Claude, J., E. Paradis, H. Tong & J.-C. Auffray. 2003. A geometric morphometric assessment of the effects of environment and cladogenesis on the evolution of the turtle shell. Biological Journal of the Linnean Society 79: 485-501.

[C76] Cope, E. D. 1876. Report upon the extinct Vertebrata obtained in New Mexico by parties of the expedition of 1874. Geographical Surveys West of the One Hundredth Meridian 4(2): i-iv, 1-370.

[GM88] Gaffney, E. S., & P. A. Meylan. 1988. A phylogeny of turtles. In The Phylogeny and Classification of the Tetrapods, vol. 1. Amphibians, Reptiles, Birds (M. J. Benton, ed.) pp. 157-219. Clarendon Press: Oxford.