Of their evolution we have little direct knowledge, but probably they are descended from the Iguanodonts and Camptosaurs of the Comanchic, and their quadrupedal gait, huge heads, short tails and other peculiarities are secondary specializations, their ancestors being bipedal, long-tailed, small headed and hornless.
The fine skulls of _Triceratops_, _Monoclonius_, _Ceratops_ and _Anchiceratops_ in the Museum collections illustrate the variety of these remarkable animals.

Complete skeletons of the first two genera are being prepared for mounting and exhibition..