A new species of 'super-armoured' worm, a bizarre, spike-covered creature which ate by filtering nutrients out of seawater with its feather-like front legs, has been identified by palaeontologists. The creature, which lived about half a billion years ago, was one of the first animals on Earth to develop armour to protect itself from predators and to use such a specialised mode of feeding. The creature, belonging to a poorly understood group of early animals, is also a prime example of the broad variety of form and function seen in the early evolutionary history of a modern group of animals that, today, are rather homogenous. The results, from researchers at the University of Cambridge and Yunnan University in China, are published today (29 June) in the journal PNAS.

The creature has been named Collinsium ciliosum, or Hairy Collins' Monster, named for the palaeontologist Desmond Collins, who discovered and first illustrated a similar Canadian fossil in the 1980s. The newly-identified species lived in what is now China during the Cambrian explosion, a period of rapid evolutionary development around half a billion years ago, when most major animal groups first appear in the fossil record. 

A detailed analysis of its form and evolutionary relationships indicates that the Chinese Collins' Monster is a distant early ancestor of modern velvet worms, or onychophorans, a small group of squishy animals resembling legged worms that live primarily in tropical forests around the world.

"Modern velvet worms are all pretty similar in terms of their general body organisation and not that exciting in terms of their lifestyle," said Dr Javier Ortega-Hernández of Cambridge's Department of Earth Sciences, one of the paper's lead authors. "But during the Cambrian, the distant relatives of velvet worms were stunningly diverse and came in a surprising variety of bizarre shapes and sizes."