414 



MESOZOIC TIME. 



beds of Colorado and Wyoming. Figures of the limbs of the two kinds are given, from 

 Marsh, on Plates I., II., III. The biped or more bird-like Dinosaurs resembled birds in 

 having the feet very similar in the phalanges; the long bones of the leg generally hol- 

 low; the pelvis bird-like in many of its details, as seen on comparing Fig. 4, Plate III., 

 with Fig. 7, Plate IV. The Morosaurus (Plate I.) and related species (p. 433) used all 

 fours in locomotion, and were far from bird-like in structure; yet it was probably able 

 to raise itself on its hind legs against a tree for browsing, though not to perfect erect- 



Figs. 726-729. 



The bones of a Dinosaur, " as large as a hound," were found near 

 Springfield, Mass., and named, by Hitchcock, Megadactylus. (This 

 name having been before used, Marsh has substituted Amphisaurus.) 

 Its leg bones were slender and hollow, like those of birds, and the 

 walls thin and dense. Portions of the skeleton of a related species 

 were found in the red sandstone near Windsor, Connecticut. The 



tooth of another species called Clep- 

 sysaurus, found both in Pennsylvania 

 and North Carolina, is represented in 

 Fig. 727. A skull, with teeth four 

 inches long (Fig. 729), from Prince 

 Edward's Island, has been called 

 Bathygnathus by Leidy. 



Crocodilians. — Figs. 726, 728, 

 represent teeth referred to species of 

 the Triassic genus Belodon. Fig. 

 726 repre ents one of the posterior 

 teeth of B. prisons, and 728, one of 

 the anterior of B. Carolinensis, both 

 from the coal-bearing Triassic beds of 

 lep . North Carolina. Another, described 



sysaurus Pennsylvania; 728, Belodon by Cope, B. UpturUS, from the Phe- 

 Carolinensis; 729, Bathygnathus borealis nixyille bone bed? Pennsylvania, had, 



according to the describer, a length 

 of about ten feet, and a habit stouter than that of the Crocodiles of 

 the present day. The teeth, in the Belodon s, were in sockets, and 

 hence the name Thecodonts applied to the group, derived from the 

 Greek 6rji<r], case, and dSovs, tooth. While Crocodilians, these saurians 

 had some of the characteristics of the Lizards. The foreign species 

 come from the Upper Trias of Germany. 



Bones, found at Phcenixville, Pa., that were formerly referred to a 

 Pterosaur or flying lizard, have since been supposed by Cope to belong 

 to a Rhynchosaur ; but their true nature is still in doubt. 



Enaliosaurs or Swimming Saurians. — Leidy has described a spe- 

 cies of Enaliosaur (or Sea-saurian, as the word signifies), from the 

 Triassic rocks of Humboldt County, Nevada. 



