This conclusion was challenged in 2011 by ceratopsian specialist Andrew Farke. He published a redescription of Nedoceratops hatcheri, a problematic species that at various times has been considered a representative of its own genus, a synonym of a species of Triceratops, a distinct species of Triceratops, or, under the Scannella–Horner hypothesis, an example of an intermediate growth stage between Triceratops and Torosaurus. Farke concluded that Nedoceratops hatcheri is an aged individual of its own genus, closely related to Triceratops. He also regarded the changes required to "age" a Triceratops into a Torosaurus to be without precedent among ceratopsids, requiring addition of epoccipitals, reversion of bone texture from adult to immature back to adult, and late growth of holes in the frill.
