What is an egg laying mammal?

The platypus (Ornithorhynchus anatinus),[3] sometimes referred to as the duck-billed platypus,[4] is a semiaquatic, egg-laying mammal endemic to eastern Australia, including Tasmania. The platypus is the sole living representative or monotypic taxon of its family (Ornithorhynchidae) and genus (Ornithorhynchus), though a number of related species appear in the fossil record.

Duck-billed platypus is an egg-laying mammal found in eastern Australia. It is the sole living representative in its genus Ornithorhynchus.