The American Museum Journal 
Vou. VIII APRIL, 1908 No. 4 
THE TRACHODON GROUP. 
INOSAUR remains which are complete enough to put together 
as articulated skeletons are rare. Among the best preserved 
of them are bones of members of the Trachodont family. Here- 
tofore, it has been necessary to content ourselves with exhibiting single 
specimens, except in the case of Allosaurus, which has been mounted as 
if it were in the act of feeding upon the remains of a Brontosaur. The 
Museum, however, has recently acquired ‘Trachodon material including 
two nearly complete skeletons, and these have been mounted together in 
a group, so that each represents a characteristic attitude of the living 
animal. ‘The accessories consist of fossil plants belonging to the same 
period and suggesting the natural surroundings and the food of the 
animals. 
This group takes us back in imagination to the Cretaceous period, 
more than three millions of years ago, when Trachodonts were among 
the most numerous of the dinosaurs. ‘l'wo members of the family are 
represented here as feeding in the marshes that characterized the period, 
when one is startled by the approach of a carnivorous dinosaur, Tyran- 
nosaurus, their enemy, and rises on tiptoe to look over the surrounding 
plants and determine the direction from which it is coming. "Vhe other 
Trachodon, unaware of danger, continues peacefully to crop the foliage. 
Perhaps the erect member of the group had already had unpleasant 
experiences with hostile beasts, for a bone of its left hind foot bears 
three sharp gashes which were made by the teeth of some carnivorous 
dinosaur. 
By thus grouping the skeletons in life-like attitudes, the relation of 
the different bones can best be shown, but these, of course, are only two 
of the attitudes commonly taken by the creatures during life. Mechani- 
cal and anatomical considerations, especially the long straight shafts 
of the leg bones, indicate that dinosaurs walked with their limbs straight 
