19 native species and 3 introduced/naturalized

Turtles are the reptiles that carry their house around on their backs. In softshelled turtles, the shell is made of cartilage. In hard-shelled turtles, it is a bony extension from the ribs. We use the shape of the carapace (top shell) and the plastron (bottom shell) as one characteristic to distinguish species. The carapace can be flattened or domed, keeled or unkeeled, flared or rounded. The scales, or scutes, may be smooth or inscribed and rough. The margins may be notched, serrated, or entire (smooth). The plastron may have one hinge, or two, which allows the turtle to close up. Or it may have no hinges. Of course, colors on the shell as well as on the head, neck and legs are important. We can sometimes use the color of the eyes to distinguish males from females.

Turtle and Tortoise Anatomy​

Box and Water Turtles (Emydidae)

The largest family of turtles worldwide, the Emydidae family, is represented in Maryland by thirteen species of turtle. With such diversity comes a variety of body types and habitat choices. Usually, the carapace is not highly domed, but there are a few species with high arches to their shells. Many species have a plastron that hinges, allowing for complete or partial closure. Several are almost completely aquatic while others are primarily terrestrial. The name Emydidae comes from the Greek "emys", meaning "freshwater terrapin", but some of our turtles will also use brackish water.​​

​	Bog Turtle​ (G​lyptemys muhlenbergii​)​ Threatened Photo courtesy of Stephen Badger
​	​Spotted Turtle​​ (Clemmys guttata​) Photo courtesy of Tony Prochaska
​	​Wood Turtle (Glyptemys insculpta) Photo courtesy of Linh Phu
​​	​Eastern Box Turtle (Terrapene​ carolina​​) Photo courtesy of Scott A. Smith
​	​Red-eared Slider (Trachemys scripta elegans) Introduced Photo courtesy of John White
​	​Eastern Painted Turtle (Chrysemys p. picta​) Photo courtesy of Corey Wickliffe​
​	​Midland Painted Turtle (Chrysemys picta marginata) Photo courtesy of Linh Phu​​
​	​River Cooter (Pseudemys concinna​​) Introduced; not established in Maryland yet Photo courtesy of John White Former Name: Eastern River Cooter
​	​Northern Red-bellied Cooter (Pseudemys rubriventris​) Photo courtesy of John White
​	​Northern Map Turtle (Graptemys geographica​​​) Endangered Photo courtesy of Jim Harding
​	Diamond-backed Terrapin (Malaclemys terrapin​​) Photo courtesy of Lori Erb Former Name: Northern Diamond-backed Terrapin
​​	False Map Turtle (Graptemys pseudogeographica​) Introduced Photo courtesy of by Peter Paplanus CC by 2.0
​	Yellow-bellied Slider (Trachemys scripta scripta) Introduced Photo courtesy of John White

Musk and Mud Turtles (Kinosternidae)

As the name implies, some of these turtles will release a strong scent when disturbed. They have paired glands on either side of the body, just inside where the bridge connects the carapace and plastron. Although they may bask, our two Kinosternids are primarily aquatic. A good way to tell the difference between mud and musk turtles is by looking at the plastron. In eastern mud turtles (Kinosternon subrubrum), the plastron is relatively large with 2 hinges. Our eastern musk turtle (Sternotherus odoratus), formerly called the stinkpot, has a much reduced plastron with only 1 hinge.​

​	​Striped Mud Turtle (Kinosternon baurii) Photo courtesy of Brenda and Jim Bardsley
​	​Eastern Mud Turtle (Kinosternon subrubrum) Photo courtesy of Mark Tegges
​	​​​Eastern Musk Turtle (Sternotherus odoratus) Photo courtesy of John White

Snapping Turtles (Chelydridae)

Currently, in the world there are only two living members, or genera, of the Chelydridae family, our own snapping turtle (Chelydra serpentina) and the alligator snapping turtle, which is not found in Maryland. There are also seven extinct genera of this family.

As the name suggests, this turtle is known for its surly disposition when threatened. Their very long necks allow them to reach farther than other turtles to snap at predators coming from behind. Never pick up a turtle by its tail; this can damage the animal's spine.​

​	Snapping Turtle (Chelydra serpentina​) Photo courtesy of Linh Phu​​ Former Name: Eastern Snapping Turtle

Softshell Turtles (Trionychidae)

The bony scutes found in hardshell turtles are missing in these softshelled cousins. The carapace is leathery while the plastron is much reduced. Our one species, the eastern spiny softshell is primarily aquatic. Their long tubular snouts act like snorkels, allowing the animals to remain submerged but still breathe.​

​	​Spiny Softshell (Apalone spinifera​​) In Need of Conservation Photo courtesy of Linh Phu​​ Former Name: Eastern Spiny Softshell

Sea Turtles (Cheloniidae and Dermochelyidae)

These turtles are fully aquatic, emerging from the waters only to breed and lay eggs. In addition to huge lungs, they can also do without oxygen from the air as they submerge for up to 30 minutes. Most have hard shells; the leatherback (our only member of the Dermochelyidae Family) lacks a bony carapace and instead has skin embedded with little bony deposits over it back.

All species of sea turtles are listed as Threatened or Endangered.​​​​​​​​​

​	Loggerhead Sea Turtle (Caretta caretta) Threatened Photo courtesy of John White
​​	Kemp’s Ridley Sea Turtle (Lepidochelys kempii​​) Endangered Photo courtesy of the National Park Service
​​	​Green Sea Turtle (Chelonia mydas​​) Threatened Photo courtesy of iStock
​	Leatherback Sea Turtle (Dermochelys coriacea​​) Endangered Photo courtesy of Scott R. Benson, NMFS Southwest Fisheries Science Center
​​​	​Hawksbill ​Sea Turtle​ (Eretmochelys imbricata​)​ Former Name: Atlantic Hawksbill Sea Turtle Endangered Photo courtesy of iStock​

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