With the bill of a duck, the body of an otter, and the tail of a beaver, the platypus (Ornithorhynchus anatinus) has a long history of confounding the humans who’ve encountered it. Early European settlers took to calling the strange, semi-aquatic mammals they found living in eastern Australian streams “duckmoles.” When Captain John Hunter, the second governor of the New South Wales colony, sent a specimen of the creature to British naturalist George Shaw in 1798, Shaw initially thought it was a hoax. Thus ensued “a rivalry that pitted nation against nation, naturalist against naturalist, and professional against amateur,” wrote evolutionary biologist Brian K. Hall in a 1999 BioScience article on the history of scientific debate over the species. “Long after the evidence was wrested from Nature half a world away from where the debate raged, biologists continued to argue about this paradoxical creature.”

For much of the two centuries since Western scientists began trying to make sense of this furry egg-laying animal—which shares its reproductive strategy with only one other mammal, the echidna—the scientific literature amounted to little more than descriptions of its odd looks, historical accounts of sightings in this river or that, and cursory observations about its anatomy and life history. That’s largely because, unlike other iconic Australian species like the slow-moving, tree-hugging koala or the ubiquitous kangaroo, platypuses are maddeningly difficult to study. Active at night and living much of their lives underwater, their habits are the opposite of their human observers’. “And beyond that,” says Geoff Williams of the Australian Platypus Conservancy, “everything you typically use in research, you can’t use with the platypus. You can’t look for tracks, and they defecate in the water, so you can’t look for scat.”