It’s Based On A Japanese Show
Toei Studios created Super Sentai back in 1975. The first set lasted for two years, but then after that, the Rangers received a new theme each year. The kids in Japan got to watch five different casts of Rangers.
America’s version became based on the Beast Rangers of Dinosaur Corps, which is the 16th version of Toei’s. Toei chose that theme “to ride on the dinosaur fever generated by Jurassic Park.” That’s when the characters and the likeness got licensed to Saban Entertainment.