Which Australian mammal has males with venomous ankle spurs?

The platypus is the Australian mammal whose males have venomous ankle spurs.

A male platypus has a sharp spur on each hind leg connected to venom glands. The venom is not normally used to kill prey; it is mainly associated with competition between males during the breeding season. A sting can cause intense pain and swelling in humans, although it is not usually fatal.

Platypuses live in freshwater systems in eastern Australia, including rivers, creeks, and lakes. They have a broad bill, webbed feet, dense waterproof fur, and a flattened tail. Their bill detects electrical signals and movement from small aquatic animals while they forage underwater with their eyes and ears closed.

The species became famous because it combines traits associated with several animal groups. It lays eggs, produces milk, has fur, and has a bill resembling a duck’s. Echidnas are the only other living egg-laying mammals, but they do not have the same venomous ankle spurs.