Sanctacaris is a Middle
Cambrian arthropod from the
Burgess shale of
British Columbia. The animal is up to 10 cm in length [46 to 93mm].
Sanctacaris appears to be a primitive
chelicerate arthropod. The chelicerates include
spiders[?],
scorpions, etc. The head of
Sanctacaris bears five pairs of grasping appendages and a sixth pair of large separate appendages. The grasping appendages each bear a short
antenna-like second appendage. There are 11 body segments each with a pair of walking legs and gills. There is a broad, flat paddle-like
telson[?]. Originally
Sanctacaris was called informally 'Santa Claws'. Unlike most other Burgess forms,
Sanctacaris is not present in
Walcott[?]'s
1909 quarry and was discovered at a different level by Desmond Collins in
1980-
1981.