The Platypus Paradox

For many years the platypus has challenged our understanding of the natural order. This paradoxical animal has been a subject for awe, fierce debate and consternation. A mysterious creature, it shares defining characteristics with mammals, birds and reptiles, defying easy classification. This apparently illogical nature has made the platypus one of the most esteemed creatures in the world. In 2000, when it was proposed that the Greater Blue Mountains should be listed as a World Heritage Site, one argument put forward was that it was home to the platypus. After European settlement the platypus would tease the greatest minds in natural history for almost 100 years.

The first known description of the platypus comes from the Wiradjuri tribe, whose area includes the Wolgan and Capertee Valleys and the land to the west. The description starts with the story of a duck, Gayger, who lived on Narwang Lake. For probably thousands of years the Wiradjuri tribe have used this story to give moral lessons to their young adolescent girls.

Gayger and her family had lived on the lake for many generations. She was told by her elders, to never wander from the safety of the lake. Despite her family warnings, she strayed off the lake and entered the river. As she traveled the river, the land features are named in the story…her journey continues until she is taken by an old water rat. The naming of the land features in the story is a songline (or storyplace) which is how the aboriginal community map the land, through story.

Finally Gayger escapes the water rat and goes back to lake. In spring time, when her babies were born, everyone knew that her babies had something wrong. The elders told Gayger that she could not stay and she left the lake. This time she traveled down another river, and the storyline names the land features in the story. She passed the Warranbungles down the river system to Flat Rock, a sacred site. The waters were too cold for Gayger because she was used to the lake but her babies liked the river system. At Flat Rock Gayger died but her babies lived…they were a curious combination between a duck and water rat, with a bill like a duck, web feet like a duck, but they had fur and a tail. This was the story of the creation of the Billadarung ( which is Waradjuri for platypus). The moral lesson for young girls is to not to venture too far away from their family, where they can be protected from harm.

In 1798, a naturalist called Dobson sent the British Museum a platypus skin. It was the first time that the platypus was first observed by Europeans. It confused the naturalists of the time because it challenged their model of the animal world. In 1800, the platypus was named Ornithorhynchus paradoxus, in view of its confusing nature. Ornithorhynchus means duck-billed and paradoxus means paradoxical.

The British Museum’s first response to the platypus skin was to see it as a prank. It was assumed that a duck’s beak had been grafted onto the body of a quadruped. This was not that farfetched as Chinese taxidermists had already established a reputation for grafting different animals together to represent mythical creatures. After a fruitless search for evidence of such grafting, naturalists realised it was genuine and were left with the daunting task of classifying the creature. Scientists began to consider that the platypus must be placed into a new genus. Its unique nature, combining attributes of fish, birds and quadrupeds, left no other choice.

As a furry quadruped, the logical conclusion was to classify it as a mammal, but it lacked nipples. Later it was discovered that the platypus has pore like glands which secrete milk. Even more perplexing were the female reproductive organs. They resembled those of a bird and reptile, yet it could not be classified as a bird because it did not have wings. Nor could it be considered a reptile because it had a heart with four chambers. In 1803, the category of monotremes was created which included both platypus and echidna. These two species were out on their own in terms of defining characteristics. Nevertheless it took science some eighty more years to understand the full nature of a monotreme.

In 1831, Lieutenant Maule opened some platypus burrows and found eggshells, which proved that, like birds, it has a single tract for eggs and waste. By this time the platypus’s mammalian characteristics had been confirmed since they are warm blooded, they have hair on their bodies, and produce milk to feed their young.

In 1836, Charles Darwin recorded his encounter with a platypus, during his travels along Coxs River near the Wolgan Valley:

In the dusk of the evening I took a stroll along a chain of ponds, which in this dry country represented the course of a river, and had the good fortune to see several of the famous Ornithorhynchus paradoxus. They were diving and playing about the surface of the water, but showed so little of their bodies, that they might easily have been mistaken for water-rats. Mr. Browne shot one: certainly it is a most extraordinary animal; a stuffed specimen does not at all give a good idea of the appearance of the head and beak when fresh; the latter becoming hard and contracted.

In 1884, 86 years after the discovery of the animal, a British Naturalist named William Caldwell was sent to Australia to study the platypus. Caldwell ended the confusion, when he sent a telegram to the University of Sydney saying that monotremes were both mammalian and oviparious. He demonstrated that they laid eggs, and there was no embryonic development in the mother.

Decades later the playtpus, along with the echidna, were placed in the mammal family. Modern fossil and genetic evidence shows that the monotreme line diverged from other mammalian lines about 150 million years ago and that both the short-beaked and long-beaked echidna species are derived from a platypus-like ancestor.