152 Prof. O. C. Marsh—Restoration of Dinosaurs. 
evidently quite slender and flexible. The short neural spines and 
the diminutive chevrons directed backward indicate a tail not com- 
pressed, but nearly round, and one usually carried free from the 
ground. 
The type specimen of Anchisaurus, here restored, was found in 
Connecticut, in the upper portion of the Triassic sandstone. The 
associated fossils were carnivorous dinosaurs and plants. 
The present restoration will tend to clear up one point long in 
doubt. The so-called “ bird-tracks” of the Connecticut river sand- 
stone have been a fruitful subject of discussion for half a century or 
more. That some of these were not made by birds has already been 
clearly demonstrated by finding with them the impressions of fore 
feet, similar to those made by reptiles. Although no osseous remains 
were found with them, others have been regarded as footprints of 
birds, because it was supposed that birds alone could make such 
series of bipedal, three-toed tracks, and leave no impression of a tail. 
It is now evident, however, that a dinosaurian reptile like Anchi- 
saurus and its near allies must have made footprints very similar to, 
if not identical with, the “bird tracks” of this horizon. On a firm 
but moist beach, only three-toed impressions would have been left 
by the hind feet, and the tail could have been kept free from the 
ground. On a soft, muddy shore, the claw of the first digit of the 
hind foot would have left its mark, and perhaps the tail also would 
have touched the ground. Such additional impressions the writer 
has observed in various series of typical “bird tracks” in the 
Connecticut sandstone, and all of them were probably made by 
dinosaurian reptiles. No tracks of true birds are known in this 
horizon. 
Restoration of Ceratosaurus.. (Plate VI.) 
In the same horizon of the Jurassic in which Brontosaurus and 
Stegosaurus were found, the skeleton restored in Plate VI. was like- 
wise discovered. It pertained to a typical carnivorous dinosaur of 
medium size, which doubtless was one of the various enemies of 
the large herbivorous forms. The restoration represents the reptile 
one-thirtieth natural size, and in a position it must have frequently 
assumed in life. The type-specimen on which this restoration is 
based has already been described by the writer.! 
The skull of Ceratosaurus is very large in proportion to the rest 
of the skeleton. The posterior region is elevated, and moderately 
expanded transversely. The facial portion is elongate, and tapers 
gradually to.the muzzle. Seen from above, the skull resembles in 
general outline that of a crocodile. The nasal openings are separate 
and lateral, and are placed near the end of the snout, as shown in 
Plate VI. 
Seen from the side, this skull appears lacertilian in type, the 
general structure being light and open. From this point of view, 
one special feature is the large, elevated, trenchant horn-core situated 
1 American Journal of Science, vol. xxvii. p. 329, April, 1884; vol. xxviii. 
p- 161, August, 1884; and vol. xliv. p. 347, October, 1892. ‘ . 
