California Reptiles & Amphibians

Identifying California Turtles

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California Turtles:

This is not a detailed key to identifying turtles found in California, just a simple guide for someone who wants to identify a turtle by color, pattern, and other physical characteristics as well as by geographical location within the state. You can read more information about each turtle by clicking on the blue name links.

Besides sea turtles, there are only three species of native California turtles, and four non-natives which have established themselves with breeding populations in the state, mostly around populated areas.

A turtle found in the wild in California may not be a native turtle or even one of the established non-natives seen here. In populated areas, especially in ponds and lakes in city parks, you will often find exotic turtles which have been released by irresponsible pet owners. These turtles may be similar in appearance to the turtles shown here. In order to identify them you will need a comprehensive guide to turtles of the world, since these pet turtles can originate from just about anywhere.

When identifying a turtle here, it is good idea to start by looking at the California Turtles Range Maps to see which turtles occur in the area where the turtle was found. To compare the general appearance of all of the established California turtles, you can look at the California Turtles Photo Index. You can also start by looking at a few basic field marks that are found on some California turtles.

A few diagnostic field marks to look for

Large legs shaped like flippers, with no toes. Sea Turtles	Red stripe on head. Rear of shell serrated. Red-eared Slider	Yellow stripes on head. Red coloring on shell. Western Painted Turtle	Large size, jagged shell barely covering body Snapping Turtle
Radiating lines on shell scales Western Pond Turtle	Flat Shell Spiny Softshell	Long thin snout Spiny Softshell	HIgh domed shell with prominent growh lines. Desert Tortoise

Most Commonly-seen California Turtles (excluding the desert)

There are very few species of turtles found in California, so if you see one at the edge of a pond or stream in the majority of the state, it is almost always one of the following three species. From a distance, these three species all look pretty much the same, with a fairly low, smooth shell with no keel along the top, that often appears a solid dark color when seen at a distance.

If you can get a good look at the head, that should be all you need to do to differentiate them, but there are some characteristics of the shells which can help also.

Red-eared Slider
Trachemys scripta elegans

Western Painted Turtle
Chrysemys picta bellii

Western Pond Turtle
Actinemys marmorata

Red stripes behind the eyes will identify this turtle.

Yellow stripes on the head with no red will identify this turtle.

Mottled dark markings without stripes will identify this turtle.

If you can't get a good look at the head (a telescope or binoculars are usually necessary) then take a look at the shell (and plastron, if possible).

Rear edge of shell is serrated, not marked with red.

Rear edge of shell is smooth, not serrated, and usually marked with red.

Rear edge of shell is smooth, not serrated, not marked with red.

Shell usually has a network of yellow lines, though often they are not visible.
There is no red coloring on the shell or plastron.

The front edge of the shields are bordered with red or yellow. Red is usually seen on the underside and edges of the shell.

A pattern of spots or lines radiates from the centers of the scutes on the shell.
There is no red coloring on the shell or plastron.

The plastron has no red.

The plastron is red with a large dark marking in the center.

The plastron has no red.

Distribution in California - in red

Distribution in California - in red, yellow, and green.

Where in the state you see a turtle can also help to identify it, but beware that the Slider and the Painted Turtle are non-natives, so they can show up near almost any water source, especially near populated areas.

These next four turtles should be fairly easy to differentiate since they are all significantly distinct in appearance, range, habitat, or behavior from any other established California turtle.

Eastern Snapping Turtle - Chelydra serpentina serpentina

This non-native turtle can be identified by its heavily serrated shell, massive head, tail with a sawtoothed crest, and its large shell which looks like it is too small for the body. This turtle is rarely seen since it does not usually bask outside the water, and its range is not widespread. The map shows some general locations where this turtle has been seen, but probably not all of them.

Heavily serrated shell.

Massive head without strong colored stripes or dark mottling.

Old turtle with a smoother shell.

Distribution in California

Sonoran Mud Turtle - Kinosternon sonoriense sonoriense

This small native turtle was once found along the Colorado River, but after the river was significantly altered by agriculture and dams, it has not been seen in the area and can be considered either extinct or at best extremely rare in the state.

It can be identified by its small size, its elongated domed carapace, its mottled head, and its range. There are no other turtles with a similar appearance in its area. A plastron with 11 scutes and two hinges are also unique among similar California turtles which have 12 scutes on an unhinged plastron.

Elongated domed shell

Mottled head with nipple-like projections on the throat.

Hinged plastron with 11 scutes.

Distribution in California

Texas Spiny Softshell - Apalone spiniera emoryi

The non-native Texas Spiny Softshell has been introduced and established along the Colorado River and the Imperial Valley, and in San Diego County. It has also been reported from other scattered locations, but most likely it has not been established in these areas. This turtle can be easily identified by its very flat, smooth, shell, it's long snout, and its range.

Flat, olive-gray shell with no visible plates or scutes.

Long thin snout with nostrils at the end.

Distribution in California

Desert Tortoise - Gopherus agassizii

This native tortoise is limited to hot dry desert regions. It can be identified by its terrestrial lifestyle, its large unwebbed limbs, its high domed shell with prominent growth lines on the scutes, its unwebbed toes and elephant-like skin, and by its occuance in the desert away from water sources. Nevertheless, it was once a popular pet and released animals can be found anywhere. (I saw one at a golf course in San Francisco.)

Head is unmarked, with large scales.

Some adults and juveniles have light patches on the scutes.

High domed shell.

Growth lines on the scutes.

Distribution in California