Ornithorhynchus is a monotreme mammal genus in the family Ornithorhynchidae, represented extantly by Ornithorhynchus anatinus, the platypus. Members of this genus are characterized by oviparity, electroreceptive bill structures, dense waterproof fur, webbed limbs adapted for semi-aquatic locomotion, and a cloaca. Males possess crural spurs connected to venom glands, a rare trait among mammals. Ornithorhynchus exhibits a mosaic of reptilian and mammalian traits, including a low metabolic rate, lack of nipples with milk secretion via areolar patches, and a highly derived sex chromosome system, making it a key taxon for studies of mammalian evolution, genome architecture, and reproductive biology.
Between 280 and 200 million years ago, a group of animals evolved which would eventually give rise to mammals, including humans: the therapsids. They were first described more than 150 years ago, based on fossils from South ...
Evolution
Apr 12, 2026
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The combination of a beaver-like body and duck-like bill of the platypus (Ornithorhynchus anatinus) is only the first of a long list of strange features on this unique creature. These odd mammals also lay eggs, have venomous ...
We humans have long viewed ourselves as the pinnacle of evolution. People label other species as "primitive" or "ancient" and use terms like "higher" and "lower" animals.
Evolution
Feb 9, 2026
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Millions of years of isolation have shaped Australia's extraordinary mammal fauna into species unlike anywhere else in the world, from platypus to koalas and wombats. Tragically, Australia is the world leader in mammal extinctions.
Plants & Animals
Jan 25, 2026
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