Cephalocarida (Horseshoe Shrimp)
Order: Brachypoda
Family: Hutchinsoniellidae (5 genera; 12 species)
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Lightiella serendipita | Jones, 1961 | San Francisco Horseshoe shrimp | - | San Francisco Bay, Brooks Island, California, USA | Rediscovered | Access |