Cats are known for being elusive and stealthy, but the southern tigrina takes those qualities to a new level. For decades, this South American feline has been hiding in plain sight, mistaken for a close relative called the tigrina or oncilla.

Physically, the two species are almost indistinguishable—both look like domestic cats with leopard-like spots. There southern tigrina is slightly darker than its north-eastern cousin, its spots are slightly larger, its tail is slightly shorter, and its ears are slightly rounder. But there’s more physical variation within each species than between them.

It’s their DNA that reveals the gulf between them. By analysing the genes of 115 “tigrinas” from all over Brazil, Tatiane Trigo showed those in the north-east are genetically