| Branchioplax Temporal range:   | |
|---|---|
|   | |
| Fossil Branchioplax washingtoniana | |
|  Scientific classification   | |
| Kingdom: | Animalia | 
| Phylum: | Arthropoda | 
| Class: | Malacostraca | 
| Order: | Decapoda | 
| Suborder: | Pleocyemata | 
| Infraorder: | Brachyura | 
| Family: | Mathildellidae | 
| Genus: |  Branchioplax  Rathbun, 1916 [1]  | 
Branchioplax is an extinct genus of crab which existed in Alaska and Washington during the Eocene period. It was first named by Mary Rathbun in 1916, and contains ten species, [1] including Branchioplax washingtoniana from the Hoko River Formation, [2] Branchioplax carmanahensis, [3] and Branchioplax ballingi. [4]