Monotrene is a term used to describe two species of egg-laying mammals found in Australia and New Guinea: the PLATYPUS and the ECHIDNA. The PLATYPUS is an aquatic mammal with a duck-like bill, webbed feet, and a beaver-like tail. It is one of the few venomous mammals in the world. The ECHIDNA is a spiny anteater that feeds on ants and termites. Both the PLATYPUS and the ECHIDNA are monotremes, which means they lay eggs instead of giving birth to live young.