Gopherus polyphemus, the gopher tortoise, is a member of Testudinidae within Cryptodira. Testudinidae is a large and diverse clade of extinct and extant terrestrial forms, and includes well-known giant species such as the Galápagos and Aldabra tortoises. Testudinidae is closely related to the Old- and New-World pond turtles (Geoemydidae and Emydidae, respectively), but the relationship of these three close relatives to other turtles is unclear (e.g., Gaffney and Meylan, 1988; Joyce, 2007). There are four extant species of Gopherus, all of which inhabit North America (Ernst and Barbour, 1989; Bonin et al., 2006).
Gopherus polyphemus is a medium-sized tortoise whose carapace length may reach 30 cm (Ernst and Barbour, 1989; Bonin et al., 2006). The skull is relatively short, and exhibits distinct posterior temporal emargination (Ernst and Barbour, 1989). The carapace is oblong, flat-topped, and drops off abruptly on the sides and at the rear. The plastron is extensive and well-developed. The forelimbs are covered with large scales. The gopher tortoise is dark brown to gray-black dorsally and yellow to gray ventrally (Ernst and Barbour, 1989; Bonin et al., 2006).
Gopherus polyphemus is found in the southeastern United States from South Carolina to Florida, and extends into eastern Louisiana. It prefers sandy soil, and habitats range from broad-leaf forest to prairies and scrub (Ernst and Barbour, 1989; Bonin et al., 2006). The gopher tortoise digs long burrows in which to sleep, estivate, and hibernate. It is herbivorous, consuming mostly grasses and leaves, but will occasionally eat insects and bones. Females lay a single clutch, normally consisting of five eggs, once per year after an elaborate courtship ritual (Ernst and Barbour, 1989; Bonin et al., 2006). Gopherus polyphemus is listed by IUCN as vulnerable, and is under constant threat due to habitat loss resulting from human activity.
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Gopherus polyphemus page by the U.S. Fish and Wildlife Service
G. polyphemus page on the Animal Diversity Web (University of Michigan Museum of Zoology)