Emys muhlenbergii; Print; The bog turtle (Glyptemys muhlenbergii ) is a critically endangered species of semiaquatic turtle in the family Emydidae. The species is endemic to the eastern United States. It was first scientifically described in 1801 after an 18th-century survey of Pennsylvania. The smallest North American turtle; its carapace measures about 10 centimeters (4 in) long when fully grown. Although the bog turtle is similar in appearance to the painted or spotted turtles; its closest relative is actually the somewhat larger wood turtle. The bog turtle can be found from Vermont in the north; south to Georgia; and west to Ohio. Diurnal and secretive; it spends most of its time buried in mud and - during the winter months - in hibernation. The bog turtle is omnivorous; feeding mainly on small invertebrates. The bog turtle is the state reptile of New Jersey.; shell