Platypus facts: the strange mammal of eastern Australia

The phrase platypus facts opens the door to one of the strangest mammals in eastern Australia. The platypus is native to eastern Australia, including Tasmania, and it packs together features that seem built from different animals.

What kind of animal is the platypus?

The platypus is an egg-laying mammal and one of the five extant species of monotremes. It is also the sole living representative of its family and genus, which makes it stand alone in a very specific corner of mammal diversity.

Its body adds to the surprise. Adult platypuses lack teeth and instead have heavily keratinised food-grinding pads. They have a single opening, called a cloaca, for both the reproductive and waste systems. A platypus also has ten sex chromosomes.

That unusual mix is part of why the animal is such a recognisable and iconic symbol of Australia.

Why did scientists think it was fake?

In 1799, the first scientists to examine a preserved platypus body judged it a fake made of several animals sewn together. That reaction makes sense when you line up the details: an egg-laying mammal with a duck-like bill, a single opening for reproduction and waste, and no teeth in adulthood.

The species kept confusing and fascinating observers long after that first judgment. A draft version of the platypus genome sequence was published in Nature in May 2008, adding another layer to its already unusual profile.

How does a platypus find food and defend itself?

The platypus uses electrolocation to detect prey in water while its eyes, ears and nostrils are closed. That means it can hunt with its face sealed off from the water while still sensing what is nearby.

It also carries a weapon that sets males apart: a male platypus has a spur on each hind foot that delivers an extremely painful venom. The platypus was born with a spur, and a male's spur injects venom, while the female loses her spur sheath as she matures.

This combination of sensory hunting and venomous defense gives the animal another place among the most unusual mammals on record.

How is the platypus protected?

The platypus has been legally protected in all states where it is found since 1912. It is also classified as a near-threatened species by the IUCN.

Another striking trait appears under ultraviolet light. The platypus is biofluorescent and glows cyan and green under ultraviolet light.

Taken together, these details show an animal with a body plan, a history, and a reputation unlike any other mammal in eastern Australia.

Test what you learned in the quiz that follows.