Turtles are very interesting creatures. There are many different types of turtles around the world. Turtles are broken into one main order and two suborders: order of Chelonia and the two suborders; Cryptodira and Pelomedusidae. Chelonia is the only main order that classifies turtles. There are 244 species, 75 genera, and 13 families of turtles according to Walter de Grutyter's, the Concise Encyclopedia of Biology. "The chelonias have short; broad, dorsiventrally compressed bodies protected by a dorsal bony shield (carapace) and a ventral bony shield (plastron)" (Gruyter 251). All species of turtles have the same basic shell structure for protection, so all Chelonias are equipped with a shell. The majority of the families can withdraw their head and legs into their shell. The skulls of turtles have no "temporal vacuities" like other families of reptiles and have no teeth either (Gruyter 251). Temporal means the side of the head and vacuities means empty space; therefore, temporal vacuity means a space or hole on the side of the skull of a turtle. Instead of teeth's, turtles have sharp horny beaks or bills (Gruyter 252). The mouths of the turtles can vary depending on the species. The Chelonias are divided into two suborders, they live in two different regions, and have the same reproductive cycle. .
The order of Chelonias is broken into two suborders. The first suborder is the Cryptodira. There are many families within this suborder. According to the Concise Encyclopedia of Biology, there are 11 families within the this sub order which are the Chelydridae, Kinosternidae, Staurotypidae, Dermatemydidae, Platysternidae, Emydidae, Testudinidae, Cheloniidae, Dermochelyidae, Carettochelyidai, and Trionychidae (Gruyter 252). Most of the turtles within this suborder live either in freshwater area such as the Chelydridae, which is the snapping turtle or primarily on land like the Testudinidae which are the tortoises.