Wikipedia
Orthrozanclus
Orthrozanclus reburrus ("Dawn scythe with bristling hair") is a sea creature known from the Middle Cambrian (~) Burgess shale, about one centimeter long, with long spikes protruding from its armored body
The describers of this fossil animal, Simon Conway Morris and Jean-Bernard Caron, say Orthrozanclus may have formed a link between the halkieriid and the wiwaxiid families, uniting them tentatively in a group called " Halwaxiida", characterized by a similar type of body armor; these organisms might have been stem group molluscs, or fall as a stem group to the larger lophotrochozoan clade (containing molluscs, annelids and brachiopods). However, the status of the Halwaxiid grouping is not universally accepted.