Rebellatrix divaricerca ("rebel coelacanth (with a) forked tail", after the unique tail fin) is a large prehistoric coelacanth from the Lower Triassic Sulphur Mountain formation and Wapiti Lake Provincial Park of British Columbia. It is the only known species of the family Rebellatricidae. R. divaricerca's most distinguishing feature was its tuna-like forked tail (unusual for an actinistian fish), which suggested a fast-swimming and active lifestyle, unlike coelacanths related to the living species.