_Dinosaur Footprints._ The ancestors of the Theropoda appear first in the Triassic period, already of large size, but less completely bipedal than their successors. Incomplete skeletons have been found in the Triassic formations of Germany[5] but in this country they are chiefly known from the famous fossil footprints (or "bird-tracks" as they were at first thought to be), found in the flagstone quarries at Turner's Falls on the Connecticut River, in the vicinity of Boonton, New Jersey, and elsewhere. These tracks are the footprints of numerous kinds of dinosaurs, large and small, mostly of the carnivorous group, which lived in that region in the earlier part of the Age of Reptiles, and much has been learned from them as to the habits of the animals that made them. The tracks ascribed to carnivorous dinosaurs run in series with narrow tread, short or long steps, here and there a light impression of tail or forefoot and occasionally the mark of the shank and pelvis when the animal settled back and squatted down to rest a moment. The modern crocodiles when they lift the body off the ground, waddle forward with the short limbs wide apart, and even the lizards which run on their hind legs have a rather wide tread. But these dinosaurs ran like birds, setting one foot nearly in front of the other, so that the prints of right and left feet are nearly in a straight line. This was on account of their greater length of limb, which made it easy for them to swing the foot directly underneath the body at each step like mammals and birds, and thus maintain an even balance, instead of wabbling from side to side as short legged animals are compelled to do. Of the animals that made these innumerable tracks the actual remains found thus far in this country are exceedingly scanty. Two or three incomplete skeletons of small kinds are in the Yale Museum, of which _Anchisaurus_ is the best known. _Megalosaurus._ Fragmentary remains of this huge carnivorous dinosaur were found in England nearly a century ago, and the descriptions by Dean Buckland and Sir Richard Owen and the restorations due to the imaginative chisel of Waterhouse Hawkins, have made it familiar to most English readers. Unfortunately it was, and still remains, very imperfectly known. It was very closely related to the American _Allosaurus_ and unquestionably similar in appearance and habits.[6] ALLOSAURUS. The following extract is from the American Museum Journal for January 1908.[7] "Although smaller than its huge contemporary Brontosaurus, this animal is of gigantic proportions being 34 feet 2 inches in length, and 8 feet 3 inches high." [Illustration: Fig. 11.--MOUNTED SKELETON OF ALLOSAURUS IN THE AMERICAN MUSEUM. _After Osborn_]