Falcatamacaris bellua
Upper Cambrian
Weeks Shale Formation
House Range, Millard County
Utah, USA

Big 141mm arthropod on 155mm slab. Extremely rare and very large for a Cambrian arthropod.

Falcatamacaris is a genus of arthropod tentatively assigned to the unranked group, Artiopoda, which includes aglaspids.

This is the kind of thing an experienced collector would consider a holy grail. It’s bizarre and unique even for the Weeks Formation, perhaps the last refuge for the lost and unchosen of the Cambrian.