A 508-million-year-old sea predator with a 'jackknife' head

Paleontologists have revisited a tiny yet fierce ancient sea creature called Habelia optata that has confounded scientists since it was discovered more than a century ago. Analysis of new fossil specimens suggest it was a close relative of the ancestor of all chelicerates, a sub-group of arthropods living today named for appendages called chelicerae in front of the mouth used to cut food. https://www.sciencedaily.com/releases/2017/12/171222090334.htm