Recognizing Turtles: Shell Patterns And Plastron Identification

With over 250 species of turtle worldwide, knowing how to identify them is an important skill for prospective owners. The first step is to determine whether the turtle is a freshwater, sea, or land-dwelling turtle. Freshwater turtles are often small with flat feet, while sea turtles have flippers for swimming and land turtles, or tortoises, have big, round shells and flat feet. From there, you can look at the shape of the shell, whether it is domed or flat, and the colour and pattern. The feet of the turtle can also be a good indicator of species, with webbed feet indicating a water-dwelling turtle, and claws indicating a land-dwelling turtle.

Freshwater turtles have flat feet and are often small

Freshwater turtles are often small and have flat feet. They are generally aquatic or semi-aquatic and spend most of their time in the water. They have toes (which may be webbed) rather than flippers.

You can identify a freshwater turtle by its shell shape and markings. Some species have distinctive colouring, such as yellow throats or red lines on their necks. Some are very small and don't grow bigger than your hand, like the stink-pot, while others are only slightly bigger, like the spotted turtle.

Box turtles are a common species of freshwater turtle. They have big, domed shells, which they can retreat into when threatened, and bright yellow or orange markings. They live near ponds and streams, particularly in muddy areas, and are often found in backyards.

Painted turtles are another common species. They have flat, olive or black-coloured shells, with red markings on the edge or underside. A southern painted turtle will also have a red stripe down its back. They tend to live in areas with shallow water, sloping logs, and flat rocks, and can often be spotted sunbathing.

Other species of freshwater turtle include musk turtles, mud turtles, map turtles, softshell turtles, and snapping turtles.

Land turtles are called tortoises and have round shells and elephant-like feet

Land turtles, also known as tortoises, are distinct from other turtles in several ways. Firstly, they have round, heavy shells that are not streamlined, which is an adaptation to their land-based lifestyle. Their shells are also generally heavier and less streamlined than those of other turtles.

The feet of land turtles are another key distinguishing feature. They have short, sturdy, elephant-like legs with clawed feet. When they move, land turtles walk on their toes. In contrast, freshwater turtles have flat feet for swimming, and sea turtles have flippers instead of feet.

Land turtles are also called tortoises and are exclusively land-dwelling. They are not adapted to living in water and are poor swimmers.

Some species of land turtles include the gopher tortoise, native to the Western Hemisphere, and the ornate box turtle, which is found in ponds and streams.

Sea turtles have flippers and smooth, flat shells

Sea turtles are easily distinguishable from other turtles by their flippers and smooth, flat shells. They are the only turtles that have flippers instead of feet, which they use for swimming.

Sea turtles are generally large and are almost always found in the sea, only coming onto land to lay their eggs. They are one of three main types of turtles, the other two being freshwater turtles and land tortoises. Freshwater turtles are generally smaller and spend most of their time in the water, although some spend less time in the water, like box turtles. Land tortoises, on the other hand, are exclusively land-based and have heavier shells. They have short, elephantine legs and walk on their toes.

The different types of sea turtles include the green turtle, the olive ridley sea turtle, the leatherback sea turtle, the loggerhead sea turtle, and the hawksbill sea turtle, each with distinct features. The green turtle, for example, has a shell that is speckled with yellow and brown, and as it ages, it becomes greener. The olive ridley sea turtle has a shorter, rounder shell that is grey or olive green, and it has more shell plates on its sides than other sea turtles. The leatherback sea turtle has a unique appearance, with a thin, flat shell that has a series of ridges running from top to bottom.

Identifying the species of a turtle is essential if you want to care for it properly. If you are still unsure, you can always consult a herp vet.

Identify the species by the turtle's size, colour, and other features

The first thing to do when identifying a turtle is to work out whether it is a freshwater turtle, a tortoise, or a sea turtle. Sea turtles have flippers instead of feet, while tortoises have elephant-like clawed feet. Freshwater turtles have flat feet.

Freshwater Turtles

Freshwater turtles are generally smaller than other turtles. They are either highly aquatic or semi-aquatic and spend most of their time in the water.

Box Turtles

Box turtles are a very common species that live in the east and southwest of the US, as well as in northern Mexico. They have big, domed shells that they can retreat into when threatened. They are often very colourful, with bright yellow or orange markings across their shells.

Painted Turtles

Painted turtles have red markings on their shells, which are relatively flat and olive or black in colour. The red "paint" is on the edge or underside of the shell, and a southern painted turtle will also have a red stripe down its back. These turtles are often found near freshwater all across the US.

Musk Turtles

Also known as stinkpots, musk turtles have a very distinctive odour. They emit a strong, almost sweet smell when they feel threatened. They are identifiable by their small size, with a length of no bigger than 5 inches (13 cm). They have flat, brown shells that can be speckled with colour, although the yellow stripes behind their eyes are easier to spot.

Mud Turtles

Mud turtles are only about 5 inches (13 cm) long at most and have round, relatively indistinct shells. The shells are round and smooth with dark brown and yellow on the bottom. The most recognisable part of this species are the scutes (plates) on the shell. While most turtles have 12 plates, mud turtles have 11.

Map Turtles

Map turtles have brown shells, but the swirling lines on the scutes make them recognisable. The design makes this turtle’s shell look like a cartographer’s map. Many types of map turtles have shells that rise to a peak in the centre. These turtles also usually have long necks and a flat head complete with lots of yellow stripes.

Softshell Turtles

Softshell turtles have a very unique shell that looks flat, smooth, and almost rubbery. They're brown and can be spotted with black dots. Unlike other turtles, their shell won’t be divided up into plates. Spiny soft shells have ridges along the front of their shells.

Snapping Turtles

Snapping turtles are big, with a width of up to 3 feet (0.91 m). They are well-known for being cranky and snapping with their powerful jaws when they are upset. Their shells also look rough and have sharp, jagged edges.

Land Tortoises

Land tortoises, unlike their aquatic cousins, prefer to dwell on land. They are poor swimmers and have heavier shells and shorter, sturdier feet.

Spurred Tortoises

Spurred tortoises are pretty big and can be up to 3 feet (0.91 m) long. They have tank-like shells that grow rings as they age. The plates, or scutes, on the brown shell are distinct and pointed.

Russian Tortoises

Russian tortoises are relatively small, about 8 inches (20 cm) long. They have bulky, round shells with brown or black scutes. The lines dividing the scutes are yellow or brown. These tortoises also have a point at the end of their tail that makes it look like a claw.

Indian Star Tortoises

Indian star tortoises are unique because of the patterns on their shells. They have black, pointy shells with white lines connecting the points on the scutes. They are otherwise pretty small, about 8 inches (20 cm) long.

Red-Footed Tortoises

Red-footed tortoises have black skin with red spots on their legs, as well as more spots right behind their eyes. Their shells are black with spiked scutes that are pale yellow. Their undersides are also black with a pale yellow stripe down the centre.

Hermann’s Tortoises

Hermann’s tortoises are pretty small, only about 8 inches (20 cm) long. They are most notable for their black-coloured shell with ringed scutes divided by yellow lines.

Sea Turtles

Sea turtles have flippers instead of feet and are always found in the ocean.

Leatherback Turtles

Leatherback turtles have a very unique appearance compared to all other sea turtles. The shell is thin and flat but has a series of ridges like stripes running from top to bottom.

Loggerheads

Loggerheads look pretty similar to other types of sea turtles, so pay close attention to their shape. They have long, almost heart-shaped brown shells. The shell has 5 plates, or scutes, down the centre and 5 longer ones on each side.

Green Turtles

Green turtles are probably what you think of when you picture a sea turtle. Their shells are speckled with yellow and brown, although they turn greener as they age. Their shells have a column of rounded scutes down the centre and 4 wider ones on each side.

Olive Ridley Sea Turtles

Olive ridley sea turtles look somewhat similar to loggerheads but have a shorter, rounder shell. Their shells are a gray or olive green colour. The main difference is the scutes on the sides of the shell—olive ridleys have 6 or more plates on each side. Other sea turtles have 5.

The top shell of a turtle is called a carapace, and the under-shell is called a plastron

The top shell of a turtle, known as the carapace, is one of the most defining features of a turtle. The carapace varies in length and shape across different species of turtles. For instance, the olive ridley turtle is the only sea turtle with a hard shell. The carapace of a wood turtle is flat and sculptured, with a central ridge or keel made up of a pyramidal pattern of grooves and ridges.

The carapace is also distinct in its colouration and patterning. For example, the carapace of a terrapin, or diamondback terrapin, features brown concentric grooves and circles on the scutes, as well as black spots on the soft grey skin of the head, neck and legs. The carapace of a map turtle, on the other hand, has a serrated edge and a saw-like vertebral keel.

The under-shell of a turtle, called the plastron, is also important in identifying different species. The common snapping turtle, for instance, has a very small plastron, often described as "bikini-like", which leaves it vulnerable to predators. In contrast, the male Blanding's turtle has a flat plastron, while the female's is arched.

The plastron also varies in colour and pattern. The plastron of the wood turtle is yellow with black spots on the corners of the scutes, while the northern red-bellied cooter has a reddish-orange or yellow plastron with a red margin, and dark lines between the scutes that fade with age.

Frequently asked questions