Scientists have uncovered fossils of a tiny faceless prehistoric sea worm with 50 spines jutting out of its head. When some unsuspecting critter came too close, its jaw-like spines snapped together and dinner was served.
The discovery reported in Thursday's journal Current Biology offers a glimpse into the Cambrian explosion of life on Earth about 541 million years ago.
The new creature dubbed Capinatator praetermissus is so different that scientists said the fossils represent not only a new species, but a new genus - a larger grouping of life - as well.
It is an ancestor of a group of marine arrow worms called chaetognatha that are abundant in the world's oceans. The prehistoric version was larger and with far more spines in its facial armory but without the specialized teeth of its descendants, said Derek Briggs of Yale University who led a team that discovered the trove of fossils in two national parks in British Columbia, Canada.
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"The spines are like miniature hooks, although more gently curved. They were stiff rather than flexible," Briggs said in an email. "It's hard to say why there are so many spines in the fossil example - but presumably thus armed it was a successful predator."
The discovery expands scientists' knowledge of a "pretty enigmatic" group of animals from the Cambrian era, said Smithsonian paleobiologist Doug Erwin, who had no role in the research.