Dinosaurs, with Special Reference to the American Museum Collections

DINOSAURS (

Dinosaurs, Tri

er Cera

For Mr. Hatcher found complete skulls, and later secured skeletons, clearly of the Dinosaurian group, but representing a race of dinosaurs whose existence, or at least their extraordinary character, had been quite unsuspected. It appeared indeed that certain teeth and skeleton bones previously discovered by Professor Cope were related to this new type of dinosaur, but the fragments known to the Philadelphia professor gave him no idea of what the

iddle Cretacic (Belly River formation) of Alberta; Anchiceratops is from the Upper Cretacic (Edmonton fo

played in the world of the late Cretacic. So far as known they were limited to North America. The most striking feature of the Horned Dinosaurs is the gigantic skull, armed with a pair of horns over the orbits and a median horn on the nasal bones in front, and with a great bony crest projecting at the back and sides. In some species the skull with its bony frill attain

and a short neck completely hidden on top and sides by the overhanging bony frill of the skull. In many respects these animals are suggestive far more than any other dinosaurs, of the great quadrupeds of Tertiary and modern times, rhinoceroses, hippopotami, titanotheres and elephants, as in the horns they suggest

et, 9? inches. The rostral bone or beak, and the lower jaw, are lacking; in the illustration on the cover they have been restor

ERAT

h it has been possible to reconstruct the entire animal. There is a mounted skeleton in the National Museum, anot

ed forward or partly upward; in one of our skulls they are 33? inches long. During life they were probably covered with horn increasing the length by six i

formation) of Alberta. One-fifteenth natural size. The horns over the eyes are

ollaterally related. None of these have the bony frill completely roofing over the neck as it does in Triceratops. There is always a central spine projecting backwards and widening out at the top to the bony margin of the frill which sweeps around on each side to join bony plates

on of Triceratops, from the mount

years shows that these Horned Dinosaurs were a numerous and varied race of which as yet we know only a few. Of their evolution we have little direct knowledge, but probably they are descended from the Iguanodont

useum collections illustrate the variety of these remarkable animals. Complete s