About Terrapene carolina (Linnaeus, 1758)
The common box turtle, Terrapene carolina, gets its common name from its unique shell structure. It has a high domed upper shell (called a carapace) and a large, hinged lower shell (called a plastron). This hinge lets the turtle close its shell completely, sealing its vulnerable head and limbs safely inside a protective, box-like enclosure. The carapace is typically brown, and usually has a variable pattern of orange or yellow markings that can be lines, spots, bars, or blotches. The plastron is dark brown; it may be a uniform color, or it can have darker blotches or smudges. The common box turtle has a small to moderately sized head and a distinctive hooked upper jaw. Most adult male common box turtles have red irises, while females have yellowish-brown irises. Males can also be distinguished from females by shorter, stockier, more curved claws on their hind feet, and longer, thicker tails. There are five living subspecies of the common box turtle. Each differs slightly in appearance, most noticeably in the color and pattern of the carapace, and whether each hind foot has three or four toes. The common box turtle lives in open woodlands, marshy meadows, floodplains, scrub forests, and brushy grasslands across most of the eastern United States, ranging from Maine and Michigan down to eastern Texas and southern Florida. The species was once found in southern Ontario, Canada, but it has now been extirpated from Canada (including Ontario). It is still found in Mexico along the Gulf Coast and in the Yucatán Peninsula. The species' range is not continuous: the two Mexican subspecies, T. c. mexicana (the Mexican box turtle) and T. c. yucatana (the Yucatán box turtle), are separated from the United States subspecies by a gap in western Texas. Three United States subspecies, T. c. carolina (the eastern box turtle), T. c. major (the Gulf Coast box turtle), and T. c. bauri (the Florida box turtle), are found roughly in the geographic regions their common names reference.
