Sanctacaris
From Wikipedia, the free encyclopedia
| Sanctacaris Fossil range: Middle Cambrian |
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Sanctacaris is a Middle Cambrian arthropod from the Burgess shale of British Columbia. The animal is up to 9 cm in length [46 to 93mm]. Sanctacaris was most famously regarded as primitive chelicerate arthropod, although subsequent studies of phylogeny have not always supported this conclusion.
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.
