Pitted Shell Turtle

What is pitted shell turtle?

The pitted shell turtle (Carettochelys insculpta) is the sole living species within the turtle family Carettochelyidae. Found in the rivers of southern New Guinea and parts of northern Australia, this unique reptile is easily distinguished by its piglike nose, flipperlike forelimbs, and a shell that lacks scutes.¹

As a large species, it can reach a carapace length of 55 cm (22 inches). It is an omnivore, consuming a diet that includes aquatic invertebrates and vertebrates, as well as fruits and nuts that fall into the water. During the nesting season, females lay clutches of 15 to 30 eggs on sandbars exposed by receding river levels.¹

Why is this turtle often called the pig-nosed turtle?

The pitted shell turtle (Carettochelys insculpta) is commonly referred to as the pig-nosed turtle because of its distinct, fleshy snout, which closely resembles the nose of a pig.¹

This unique physical feature is one of the primary characteristics that distinguishes the species from all other turtles. In addition to its piglike nose, the species is characterized by its flipperlike forelimbs and a shell that lacks the hard, horny plates known as scutes found on most other turtle species.¹

How do its flipperlike limbs help it live in rivers?

The pig-nosed turtle’s flipperlike limbs are highly specialized adaptations for aquatic locomotion. Unlike many other freshwater turtles that rely on webbed feet for paddling, the pig-nosed turtle utilizes its bladelike flippers to generate both lift and thrust in the water.

This movement is analogous to the mechanics of aerial flight in birds. By moving the flippers synchronously in a figure-eight configuration, the turtle can propel itself efficiently through its riverine environment. In this system, the upper arms act as a leverage point, while the compressed forearm and hand region function as the primary propulsive unit. This design allows for more effective navigation and swimming performance compared to species that rely solely on alternating limb movements or bottom walking.²

What makes its shell different from other turtles?

The shell of the pig-nosed turtle (Carettochelys insculpta) is distinct from most other turtles because it lacks the hard, horny plates known as scutes.¹

While the majority of turtle species possess these protective scutes covering their bony shells, the pig-nosed turtle’s carapace is instead characterized by a pitted surface, which gives the species its common name. This lack of scutes is a notable departure from the typical armored structure found in many other freshwater and terrestrial turtles.¹