When the first platypus was observed by European naturalists, they were understandably baffled. They even thought that it was a fraud committed by Chinese taxidermists. Who'd ever heard of an animal that laid eggs, was venomous, had a flat, beaver-like tail with the feet of an otter and the beak of a duck.

Now scientists are one step closer to unraveling the evolutionary mystery behind this odd animal. A report appearing in the latest issue of Nature describes some of the findings that resulted from the completion of the platypus genome.

From the abstract:

"We find that reptile and platypus venom proteins have been co-opted independently from the same gene families; milk protein genes are conserved despite platypuses laying eggs; and immune gene family expansions are directly related to platypus biology."

Here's a neat phylogenetic tree (also from the article).

You can read the full article in Nature here.