Scientists have revealed that the pink armadillo – the smallest species of armadillo – has a unique double skin.
In a new study published on December 19, 2023 in the journal Journal of ZoologyThe researchers studied the microscopic anatomy of parts of the pink armadillo (Chlamyphorus truncatus) Skin with or without osteoderms – bony plates embedded in the skin. In doing so, they revealed the unique and “strange” second layer of skin beneath the animal's dorsal armor.
“Although it may seem strange, the animal has a double layer of skin,” says the lead author Cecilia KrumboticThe biologist at Argentina's National Council for Scientific and Technical Research told Live Science. “The outer layer contains keratinized scales [in which dead tissue forms a thickened, protective layer] The osteoderms, acting as a mantle or cover over the inner layer, display abundant soft white fur. “This double skin is a unique trait among mammals.”
In contrast, 19 other known species of Armadillo They have a single layer of skin on their backs, which is covered by bony scales and dermis that form the animals' armor.
The pink fairy armadillo is only 6 inches (15 cm) long and weighs 3.5 ounces (100 grams). They are native to central Argentina, where they live in burrows dug by their relatively large claws. Researchers believe they eat mostly ants and other insects. However, their habits are poorly understood, and most captive specimens die within days.
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The pink fairy armadillo's protective carapace is usually divided into two areas: one carapace covers the head, while the dorsal carapace covers the rest of the body, Krumbotek said. The dorsal armor is further divided into a pectoral gear covering the upper back – consisting of a series of movable bands that enable the animal to retain flexibility – and a pelvic gear covering the back area.
The armor serves to protect against potential predators and supports the animal's underground lifestyle.
While their larger relatives spend a significant amount of time on the surface, pink armadillos live mostly underground.
“It is estimated that the evolution toward a completely subterranean lifestyle in the ancestral lineage of the fairy armadillo occurred between 32 and 17 million years ago,” Krumbotek said. She added that this shift was driven by changing environmental conditions that led to more arid ecosystems in southern South America.
The structure of the epidermis, or skin, of the pink, scaled armadillo is similar to that seen in juveniles of other armadillo species, where the scales are still developing.
Its unique external characteristics were likely an adaptation to a life spent burrowing in sandy soil. “The flexibility and lightness of the dorsal armor enables it to adapt to the shape of the tunnels,” Krumbutek said.
The pelvic gear is particularly suitable for this lifestyle. “The osteoderms that make up the pelvic girdle tend to fuse with each other and with the pelvic girdle and sacrum [the fused vertebrae between the pelvic bones]. The sump gear acts like a piston, compressing sediment at the back of the tunnels as it advances, Krambotic said.
Although unique, the armadillo's body covering appears similar to that of other underground mammals and it has very flexible hairs that seem to help it move through its underground tunnels.
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