What do you call a squid with two arms?

Nectocaris pteryx, of course. Which means, erm, finned swimming crab. One of the many weird squidgy things found in the famous Burgess Shale of British Columbia in Canada was a 5cm long blob with fins, stalked eyes and a pair of tentacles. There had been only one specimen collected originally, and while a few researchers had studied it - including Stephen Jay Gould and Simon Conway Morris - it wasn't until this year that it has been more firmly identified as an early cephalopod.

A group has studied a further 90 specimens collected by the Royal Ontario Museum and has recognised features of later relatives that give credence to the cephalopod tag. This is significant as it drags the origins of cephalopods back in time by a good 30 million years to 505 million years ago.