Herpetology example

Cortland Herpatology Connection

Turtle Key

See also species distribution maps at the New York State
Amphibian and Reptile Atlas Project website.

Key to the families of adult turtles in New York

1.a. Limbs paddle-like flippers 2
1.b. Limbs not paddle-like 3

2.a. Shell leathery Dermochelyidae
2.b. Shell with horny scutes Cheloniidae (species list)

3.a. Scutes absent; edges of shell flexible, snout tubelike Trionychidae
3.b. Hard scutes on shell, snout not tubelike 4

4.a. Very narrow bridge, plastron narrow Chelydridae
4.b. Bridge and plastron wider 5

5.a. 12 scutes on plastron, none vestigial Emydidae
5.b. 10 or 11 plastron scutes Kinosternidae

Key to the species of the family Emydidae of New York

1.a. Carapace highly domed, blunt curved beak on upper jaw, plastron deeply hinged so shell can completely close Eastern Box Turtle
Terrapene carolina
1.b. No distinct central beak, plastron cannot fully close 2

2.a. Neck and forelimbs light gray with dark spots, growth rings on carapace very obvious Diamondback terrapin
Malaclemys terrapin
2.b. Neck and forelimbs not light gray, may or may not show growth rings 3

3.a. Deep hinge on plastron, carapace somewhat arched and black with yellow flecking Blanding's Turtle
Emydoidea blandingi
3.b. Not as in 3.a 4

4.a. Abdominal scutes of plastron become more narrow on bridge 5
4.b. Abdominal scutes do not narrow much 6

5.a. Cusp on each side of central notch in upper jaw, rear edge of carapace smooth, light lines on head and neck all horizontal Painted Turtle
Chrysemys picta
5.b. No cusps around notch on upper jaw, some vertical lines on side of head and neck, rear edge of carapace rough Common Map Turtle
Graptemys geographica

6.a. Shell smooth, black with scattered yellow spots Spotted Turtle
Clemmys guttata
6.b. Shell with growth rings and sculpturing 7

7.a. Orange blotches behind head, carapace growth rings moderate, plastron dark with light central area Bog Turtle
Clemmys muhlenbergi
7.b. No blotches, carapace deeply sculptured, plastron is yellow with dark blotches near outer edges Wood Turtle
Clemmys insculpta

Key to the species of the family Chelydridae of New York

1.a. Only species found in New York Snapping Turtle
Chelydra serpentina

Key to the species of the family Dermochelyidae of New York

1.a. Only species found in New York Leatherback
Dermochelys coriacea

Key to the species of the family Trionychidae of New York

1.a. Only species found in New York Eastern Spiny Softshell
Apalone spinifera

Key to the species of the family Kinosternidae of New York

1.a. Head very dark with white or yellow stripes, plastron narrow with central patches of skin Common musk turtle (Stinkpot)
Sternotherus odoratus
1.b. Head olive brown with indistinct light mottling, plastron broad with no patches of skin Eastern mud turtle
Kinosternon subrubrum

Much information for the turtle keys was derived from Reptiles of North America by Hobart Smith and E. D. Brodie, Jr.