Back Sidneyia inexpectans Catalan Sidneyia Spanish Sidneyia French Sidneyia inexpectans Italian シドネイア Japanese 시드니이아 Korean Sidneyia Inexpectans Malay Sidneyia Dutch Sidneyia Polish Sidneyia Swedish
| Sidneyia Temporal range:
| |
|---|---|
| |
| Reconstruction of Sidneyia inexpectans | |
| |
| Fossil of S. inexpectans | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| (unranked): | †Artiopoda |
| (unranked): | †Vicissicaudata |
| Genus: | †Sidneyia Walcott, 1911 |
| Type species | |
| †Sidneyia inexpectans Walcott, 1911
| |
| Species | |
| |
Sidneyia is an extinct marine arthropod known from fossils found from the Early to the Mid Cambrian of China and the Mid Cambrian Burgess Shale of British Columbia, Canada.