The Leatherback Sea Turtle | Anatomy

Believe it or not, but the Leatherback sea turtle is the world’s largest reptile. The carapace, or upper shell, can grow to more than 2 m in length, and the turtle can weigh more than 500 kg. This makes the Leatherback sea turtle to the biggest of all the sea turtles. Some have even tipped the scales at 900 kg.

Anatomy – Physical characteristics of this Sea Turtle (Adult)

One way it’s different from the other sea turtles is it lacks scutes and scales and instead has a leathery carapace with prominent longitudinal ridges. The skin covers a thick layer of oil-saturated fat and connective tissue and a matrix of small bony plates that fit together, almost like a jigsaw puzzle, to form the shell.

One way it’s different from the other sea turtles is it lacks scutes and scales and instead has a leathery carapace with prominent longitudinal ridges. The skin covers a thick layer of oil-saturated fat and connective tissue and a matrix of small bony plates that fit together, almost like a jigsaw puzzle, to form the shell. The very unusual carapace is not made of bone like the usual sea turtles; instead it is made of smooth leathery skin. The carapace is around 1.5 inches thick and has several very fine ridges that run vertically all the way to the tail end of the turtle. The Carapace is usually dark grey with a few, very prominent white spots splattered on it. The shape of the carapace is rather unusual too. It is wide at the head and then narrows down at the tail end of the turtle. This gives the shell a shape of a tear drop. The bottom of the shell, called plastron, is inversely colored. It is lightly colored and has dark spots.

The Leatherbacks have huge front flippers. They are the largest flippers on any sea turtle and can grow up to an impressive 9 feet. Unlike other sea turtle the front flippers don’t have any claws on them. They don’t have a split toe end and resemble a paddle.
On the flippers we can see another major difference from the other sea turtle species. The Leatherback doesn’t have any claws on their flippers. On the other species you’ll normal see one or two claws on the flippers.

The shape of the flippers and the carapace of the Leatherbacks give it a very hydrodynamic body. It enables the turtle to swim very fast and dive very deep. The front limbs provide an amazing thrust and the smooth shell with the tear drop shape enables the turtle to power through water. The structure of the body is also the reason that the turtle can retain its body heat even in the coldest of waters.

The Leatherback turtle doesn’t have teeth; instead it has points on its upper lip which contain backward spines. These help the turtle swallow its food.

There is a pink spot on top of a Leatherback’s head. It is unique on every Leatherback, like zebra prints or finger prints. Scientists believe that this spot helps the Leatherbacks determine their location and the direction or to help the turtle sense light.

Like other sea turtles, the Leatherback, cannot retract its head or flippers under its shell, making head and flippers very vulnerable to attach from predators.

The largest Leatherback sea turtle found was over 10 feet and weighed 2019 pounds. This giant creature was found on the coast of Wales.

Anatomy – Physical characteristics of this Sea Turtle (Hatchling and Juvenile)

The Leatherback sea turtle mate at the sea. The female turtle then swims ashore to lay eggs. The females dig a hole in the sand and create the nest in a cavity. The nest, therefore, is shaped like a boot.
The process of laying the eggs is undertaken at night. This ensures the safety of the female Leatherback from predators. Eggs laid at night are more likely to hatch at night. This would provide the hatchlings a safer route to the ocean and protection from daytime predators.

The female Leatherback lays around 120 eggs at a time. These eggs are leathery and have a rather thick shell. Out of these eggs around 80 to 90 are fertile eggs. The hatchlings then hatch and make their way to the ocean. However as the female leaves the nest after eggs are laid, it doesn’t provide care for the hatchlings. So they have to make even the first journey by themselves. Most of the hatchlings die before even reaching the shore. They fair few who reach the shore have to swim for 2 days nonstop in order get to the weed on which they feed.

The hatchlings of the Leatherback turtle are very small. They average around two and a half inches in length and weigh around 1.6 ounces. They have similar characteristics of the adult sea turtle.
They have a dark colored outer shell with the similar ridges that run from the shoulder to the tail of the turtle’s shell. It also has light spots on it. Its front flippers have claws on it which help the juvenile to walk across the sand to the ocean. These claws disappear over time as the turtle grown old. The front flippers are also larger in comparison to its body than the adult turtles. These are as large as the carapace of the hatchling.