region, while the smooth soft-shelled turtle (Apalone mutica) prefers the larger rivers, creeks, and bayous. The snapping turtle family (Chelydridae) is found only in the New World with two genera, both represented in the Big Thicket, the common snapping turtle (Chelydra serpentina) and the alligator snapping turtle (Macrochelys temminckii). The alligator snapping turtle is the largest freshwater turtle in North America and one of the larger freshwater turtles in the world. One record sized individual with a shell has been documented, and another captive specimen recorded, however, and is the typical adult size. Alligator snapping turtles are protected as a threatened species in Texas. Lizards commonly seen include green anoles (Anolis carolinensis), five-lined skinks (Plestiodon fasciatus), broad-headed skinks (Plestiodon laticeps), ground skinks (Scincella lateralis), and prairie lizards (Sceloporus consobrinus). Six-lined race runners (Aspidoscelis sexlineatus) are not uncommon, but limited to open areas with sandy soils, whereas the legless western slender glass lizard (Ophisaurus attenuatus) prefers areas of dense grasses with sandy soils. Three lizards barely range into peripheral counties, including two rare skinks, the southern prairie skink (Plestiodon septentrionalis) in the west and the coal skink (Plestiodon anthracinus) in the northeast; and the Texas spiny lizard (Sceloporus olivaceus), common to the west, but rare in a few western Big Thicket counties. Most records of the state reptile, the Texas horned lizard (Phrynosoma cornutum), from east Texas are from the early and mid-twentieth century when they were popular pets, and are thought to represent released or escaped pets and not the species natural range. Two invasive species, the brown anole (Anolis sagrei) and the nocturnal Mediterranean gecko (Hemidactylus turcicus), are found there. Snakes: With 33 species, the highest diversity among the reptiles are the snakes. Some of the more common species include the eastern hognose snake (Heterodon platirhinos), brown snake (Storeria dekayi), western ribbon snake (Thamnophis proximus), and the rough greensnake (Opheodrys aestivus). Two large, common, but harmless species, the coachwhip snake (Masticophis flagellum) and the Texas rat snake (Pantherophis obsoletus), both commonly grow to ; individuals are not rare, and they occasionally grow even larger. The North American racer (Coluber constrictor) occurs in three color variations in the Big Thicket, some recognize them as subspecies, the buttermilk racer (C. c. anthicus), the yellow-bellied racer (C. c. flaviventris), and the tan racer (C. c. etheridgei). The harmless watersnakes bear a resemblance and share habitats with venomous cottonmouths, including three common species,