(named after Sidney Wallcott).
Named By: Charles Walcott - 1911.
Classification: Arthropoda, Limulavida.
Species: S. inexpectans (type).
Size: Largest specimens up to 12.7 centimetres long.
Known locations: Canada, British Columbia - Burgess Shale., Possibly also the USA.
Time period: Cambrian.
Fossil representation: Well over 100 individuals.
Sidneyia is thought to have been a carnivore of other bottom dwelling marine organisms, scouring the ocean floor and sensing them out with its antennae. So far Sidneyia is known from well over a hundred specimens, with many more likely to yet be found. Individuals ran from about five centimetres to just under thirteen centimetres on length. Sidneyia was named by Charles Walcott in 1911, and he named it after his son Sidney who actually discovered the first specimens.
- Taphonomy of the Greater Phyllopod Bed community, Burgess Shale. - PALAIOS 21 (5) -Jean-Bernard Caron & Donald A. Jackson - 2006.