Waptia fieldensis

Cambrian

Burgess Shale, Stephens Formation

Field, British Columbia, BC, Canada.

47mm if outstretched on 50mm slab.

Arthropod.

Waptia is an extinct genus of arthropod that is shrimp-like in form but it is different enough that it hasn’t been classified within any family of crustacean nor any family of arthropods for that matter – another unsolved mystery of the Burgess Shale over 100 years after its discovery.  It does appear to be at least related to the ancestors of crustaceans.