The common box turtle (Terrapene carolina) is a species of box turtle with six existing subspecies. It is found throughout the Eastern United States and Mexico. The box turtle has a distinctive hinged lowered shell (the box) that allows it to completely enclose itself. Its upper jaw is long and curved. The turtle is primarily terrestrial and eats a wide variety of plants and animals. The females lay their eggs in the summer. Turtles in the northern part of their range hibernate over the winter. Common box turtle numbers are declining because of habitat loss, roadkill, and capture for the pet trade. The species is classified as vulnerable to threats to its survival by the IUCN Red List. Three U.S. states name subspecies of the common box turtle as their official reptile. Terrapene carolina was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae. It is the type species for the genus Terrapene and has more subspecies than the other three species within that genus. The eastern box turtle subspecies was the one recognized by Linnaeus. The other five subspecies were first classified during the 19th century. In addition, one extinct subspecies, T. c. putnami, is distinguished. The common box turtle inhabits open woodlands, road sides, road middles, marshy meadows, floodplains, scrub forests and brushy grasslands in much of the eastern United States, from Maine and Michigan to eastern Texas and south Florida. It is found in Canada in southern Ontario and in Mexico along the Gulf Coast and in the Yucatán Peninsula. The species range is not continuous as the two Mexican subspecies, T. c. mexicana (Mexican box turtle) and T. c. yucatana (Yucatán box turtle), are separated from the US subspecies by a gap in western Texas. Three of the US subspecies; T. c. carolina (eastern box turtle), T. c. major (Gulf Coast box turtle) and T. c. bauri (Florida box turtle); occur roughly in the areas indicated by their names. T. c. triunguis (three-toed box turtle) is found in the central United States. Common box turtles are predominantly terrestrial reptiles that are often seen early in the day, or after rain, when they emerge from the shelter of rotting leaves, logs, or a mammal burrow to forage. These turtles have an incredibly varied diet of animal and plant matter, including earthworms, slugs, insects, wild berries, and sometimes even animal carrion.