In the vast and arid deserts of Australia lives a creature that is rarely seen by humans. The marsupial mole is a small, burrowing mammal that spends nearly its entire existence beneath the sand. Despite its common name and appearance, it is not a true mole. It belongs to the infraclass Marsupialia, meaning it is more closely related to kangaroos and koalas than to the placental moles found on other continents. This animal, known as Itjaritjari by the indigenous people of the Western Desert, embodies a unique evolutionary path shaped by one of the world’s harshest environments.
Unique Physical Adaptations
The marsupial mole’s body is adapted for a life spent digging. Its form is streamlined and tubular, covered in fine, silky fur that has a golden sheen. This coat helps reduce friction as it moves through the abrasive sand. The animal’s head is cone-shaped, and its nose is protected by a tough, horny shield that it uses to push through the soil. To further aid in this process, five of its seven neck vertebrae are fused, providing rigidity and strength for bulldozing forward.
Its powerful forelimbs are equipped with large, spade-like claws on the third and fourth digits. These claws are not used for scratching but for a powerful, parasagittal (up-and-down) chopping motion that excavates the sand in front of it. The hind feet then push the loose sand backward. The marsupial mole is functionally blind; its eyes have been reduced to simple, lens-like structures under the skin, and it lacks external ears, possessing only small auditory openings hidden by fur.
Life Beneath the Sand
Living in the dune fields and sandy river flats of Western and Central Australia, the marsupial mole does not construct permanent burrows like other fossorial mammals. Instead, it effectively “swims” through the sand, typically at depths of about 20 centimeters, backfilling its tunnel as it progresses. This constant movement is fueled by a diet of insects, especially beetle larvae and pupae, which it locates underground. It may also consume ant eggs and occasionally even small reptiles like geckos.
These creatures are solitary and are rarely observed on the surface. They are known to emerge occasionally, particularly after heavy rains, moving with a distinct, sinuous gait that leaves a characteristic three-grooved track from its feet and short, leathery tail. Though they have a low resting body temperature, their metabolic rate can increase dramatically to provide the energy needed for burrowing through the dense sand.
An Example of Convergent Evolution
The marsupial mole is an example of convergent evolution. This process occurs when unrelated organisms independently evolve similar traits as they adapt to similar environmental pressures or lifestyles. The marsupial mole of Australia and the placental golden moles of Africa, for instance, are only very distantly related but share similarities. Both possess streamlined bodies, powerful digging claws, and reduced or non-functional eyes, all adaptations for a subterranean existence.
The fundamental difference lies in their reproductive biology. As a marsupial, the female mole has a pouch to nurture its developing young. This pouch opens toward the rear, an adaptation that prevents it from filling with sand as the mother digs through the earth. Placental moles, on the other hand, lack a pouch entirely.
Conservation and Threats
Assessing the conservation status of the marsupial mole is exceptionally difficult due to its elusive nature. Because they are so rarely encountered, scientists lack sufficient population data, leading to a “Data Deficient” classification and making it hard to understand the dangers they face.
The primary threats to the species are believed to come from introduced predators. Feral cats and red foxes, which are not native to Australia, prey upon marsupial moles when they occasionally surface. Changes to their habitat also pose a risk. Soil compaction caused by livestock can make burrowing difficult, and alterations to natural fire regimes can impact the availability of their food sources.