Maryland's Turtles and Tortoises (Order Testudines)

244 species worldwide, 19 species in Maryland

Overview of Maryland’s Turtles

As every school kid knows, turtles are the reptiles that carry their house around on their backs. In softshelled turtles, the shell is made of cartilage.  In hardshelled 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 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

There are six families and nineteen species of turtles (including sea turtles) that can be found in Maryland.

Box and Water Turtles  (Emydidae)

The largest family of turtles worldwide (they are found on every continent except Australia and Antartica), this family is represented in Maryland by eleven species of turtle.   With such diversity comes a variety of body types and habitat choices. Usually, the carapace is no 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" some of our turtles will also use brackish water.

Eleven of the nineteen species of turtles in Maryland are from this family. These include: bog turtle (Glyptemys muhlenbergii), spotted turtle (Clemmys guttata), wood turtle (Glyptemys insculpta), eastern box turtle (Terrapene carolina carolina), red-eared slider (Trachemys scripta elegans), midland painted turtle (Chrysemys picta marginata), eastern painted turtle ((Chrysemys picta picta), eastern river cooter (Pseudemys concinna concinna), northern red-bellied turtle (Pseudemys rubriventris), northern map turtle (Graptemys geographica), and the northern diamond-backed terrapin (Malaclemys terrapin terrapin).

Click on a picture or species name for profiles
of each of the 11 species and subspecies of Maryland’s box and water turtles.

Musk and Mud Turtles (Kinosternidae)

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 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.

Click on a picture or species name for profiles
of each of the 2 species of Maryland’s musk and mud turtles.

 

Snapping Turtles (Chelydridae)

Currently, in the world there are only two living members, or genera, of the Chelydridae family, our own eastern snapping turtle (Chelydra serpentina serpentine) 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.

Click on a picture or species name for a profile
of Maryland’s only species of 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.

Click on a picture or species name for a profile
of Maryland’s only species of softshell turtle.

Maryland Amphibian
and Reptile Atlas Project

"A Joint Project of the Natural History Society of Maryland, Inc. and the Maryland Department of Natural Resources"

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