|Named By:||Charles Walcott in 1911|
|Time Period:||Burgess Shale|
|Location:||Canada, British Columbia - Burgess Shale., Possibly also the USA|
|Size:||Largest specimens up to 12.7 centimetres long|
|Fossil(s):||Well over 100 individuals|
|Classification:||| Arthropoda | Limulavida ||
Sidneyia is an extinct arthropod known from fossils found in the Cambrian-age Burgess Shale formation of British Columbia. 144 specimens of Sidneyia are known from the Greater Phyllopod bed, where they comprise 0.27% of the community.