Some mice tails are secretly reinforced with bony scales, just like dinosaurs

New scans have revealed that spiny mice have bony scale (shown in red) beneath the skin in their tails. (Image credit: EDWARD STANLEY)

Researchers have serendipitously discovered that all species in a mouse genus have tails secretly reinforced with bony scales. Before now, only one mammal group — armadillos — were known to possess these scales.   

Spiny mice in the genus Acomys, which contains 21 species, appear similar to common mice from the genus Mus but are more closely related to the rodent sub-family Gerbillinae, which includes gerbils and sand rats. Spiny mice have unusually stiff and bristly hairs, known as guard hairs, which shield them from abrasion and moisture.