TRIASSIC PERIOD. 413 



represents, reduced, the track of the hind foot of the most gigantic of 

 these biped Labyrinthodonts, the Otozoum Moodii. The actual length 

 of the track was tiventy inches, and the stride three feet ; and hence the 

 legs of the animal were long and stout. Eleven consecutive tracks 

 have been observed on a single slab of sandstone. The right and left 

 tracks follow one another at equal distances ; and hence the animal 

 walked or ran, and did not leap. The fore feet were sometimes, though 

 very rarely, brought to the ground ; and the form of the impression is 

 shown in Fig. 724. No impression of a tail has been observed on 

 any of the slabs ; and hence this appendage must have been short or 

 wanting altogether ; and, if the latter, the Otozoum was much like a 

 gigantic long-legged biped Batrachian, — tall enough to look over a 

 twelve-foot wall, — and furnished, in all probability, with scales like a 

 Saurian, and with teeth three or more inches long. 



Others of these amphibian bipeds were quite small, some having left 

 tracks not over a fourth of an inclTm length. Professor Hitchcock has 

 described over fifty species, from the tracks in the sandstone of the 

 Connecticut valley. 



2. Dinosaurs. — The Dinosaurs of the Triassic, while having the fore 

 feet four-toed, had the hind feet three-toed, like those of Birds. More- 

 over, the toes had the same number of joints as in Birds. Fig. 721 

 represents the fore-foot, and 721 a, the hind-foot track, from Turner's 

 Falls on the Connecticut. The latter has a prolonged heel, arising 

 from the preceding or tarsal joint coming to the ground in walking. 

 The animal was able to raise its body erect, bird-like, yet often used 

 its fore feet in locomotion. Only a very few specimens of this kind 

 have been found. 



The bones of a Triassic animal, " as large as a hound," were found 

 near Springfield, Mass., and named by Hitchcock Megadactylus, from 

 its long fingers. Cope regards it as a Dinosaur. But its fore feet 

 were nearly as long as its hind feet; and it differed therefore from that 

 which made the tracks just referred to, in being quadrupedal in locomo- 

 tion. Its leg bones were slender and hollow, like those of Birds, and 

 had thin, dense walls. A squarish impression accompanies in some 

 cases the three-toed Reptilian footprints, which appears as if made by 

 a blunt extremity of the body ; but Cope has shown that the two 

 ischial bones (the lower and posterior part of the pelvis) were pro- 

 longed backward, as in Birds, and terminated behind side by side ; and 

 that hence the impression might well have been made by their blunt 

 extremity. 



Bones of another species, called Glepsysaurus, have been found in 

 Pennsylvania by Lea, and also in North Carolina by Emmons. Fig. 

 727 represents a tooth of the species, showing that, while bird-like 



