Dermochelyoidae

Leatherback turtle Dermochelys coriacea. Photo from here.

Belongs within: Centrocryptodira.

The clade Dermochelyoidae unites the living leatherback turtle Dermochelys coriacea and its close fossil relatives with the extinct family Protostegidae. Dermochelys coriacea is the largest living turtle and is readily distinguished from other living Testudines by the lack of a solid external shell.

Synapomorphies (from Gaffney & Meylan 1988): Jugal very large, ventral process extending posteriorly to form most of cheek margin; basisphenoid and occipital elements usually poorly ossified, with portions remaining cartilaginous; forelimbs very long in relation to hindlimbs and body; trochanter major of femur very long in relation to trochanter minor, projecting proximal to femur head; intertrochanteric fossa largely obliterated by fusion of trochanter bases.

<==Dermochelyoidae [Dermochelyoidea]
    |--Dermochelyidae GM88
    |    |--Eosphargis GM88
    |    `--+--Psephophorus GM88
    |       |    |--P. calvertensis Palmer 1909 K95
    |       |    |--P. eocaenus Andrews 1901 K95
    |       |    |--P. oregonensis Palmer 1940 K95
    |       |    |--P. polygonus v. Meyer 1847 K95
    |       |    |--P. pseudostracion (Gervais 1849) K95
    |       |    |--P. rupeliensis (v. Beneden 1883) K95
    |       |    |--P. scaldii (van Beneden 1871) K95
    |       |    `--P. terrypratchetti Köhler 1995 K95
    |       `--Dermochelys coriacea Linnaeus 1766 GM88, K95
    `--Protostegidae GM88
         |--Chelospharginae GM88
         |    |--Chelosphargis GM88
         |    `--Calcarichelys Zengerl 1953 GM88, D07
         |         `--C. gemma D07
         `--Protosteginae GM88
              |--Protostega gigas GM88, N85
              `--Archelon Wieland 1896 GM88, D07
                   `--A. ischyros D07

*Type species of generic name indicated

REFERENCES

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

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

[K95] Köhler, R. 1995. A new species of the fossil turtle Psephophorus (order Testudines) from the Eocene of the South Island, New Zealand. Journal of the Royal Society of New Zealand 25: 371–384.

[N85] Norman, D. 1985 (reprinted 2000). The Illustrated Encyclopedia of Dinosaurs. Salamander Books: London.

Last updated: 11 August 2017.