Reconstruction of “Tokummia katalepsis” showing a pair of large pincers at the front for capturing prey with much of the multi-segmented body protected by a hardened shell (illustration by Lars Fields)

See Article in U of T News

https://www.utoronto.ca/news/ouch-u-t-paleontologists-identify-508-million-year-old-sea-creature-can-opener-pincers

See Article on CBC news | Technology & Science

http://www.cbc.ca/news/technology/researchers-fossil-507-million-years-1.4087009

Published in Nature Apr 26/17

Burgess Shale fossilsillustrate the origin of the mandibulate body plan (2017) http://dx.doi.org/10.1038/nature22080