These findings were contested a few years later by Catherine Forster, who reanalyzed "Triceratops" material more comprehensively and concluded that the remains fell into two species, "T. horridus" and "T. prorsus", although the distinctive skull of "T." (""Nedoceratops"") "hatcheri" differed enough to warrant a separate genus. She found that "T. horridus" and several other species belonged together, and "T. prorsus" and "T. brevicornus" stood alone, and since there were many more specimens in the first group, she suggested that this meant the two groups were two species. It is still possible to interpret the differences as representing a single species with sexual dimorphism.