LIASSIC DINOSAURS. 125 



The general condition of the almost entire skeleton of a Scelidosaur organized, 

 as seems by the structm-e and proportions of the hind foot, for terrestrial rather 

 than aquatic hfe, or at least for amphibious habits on the margins of a river rather 

 than for pursuit of food in the open sea, led me to infer that the carcass of the dead 

 animal had been drifted down a river, disemboguing in the Liassic ocean, on the 

 muddy bottom of which it would settle down when the skin had been so far 

 decomposed as to permit the escape of the gases engendered by putrefaction. In 

 that predicament the carcass would attract large carnivorous marine fishes and 

 reptiles, and portions of the skin, with prominent parts not too strongly attached 

 to the trunk, would probably be torn away before the weight of the bones had 

 completely buried the carcass in the mud. In this way, perhaps, we may account 

 for the loss of much of the dermo-skeleton and of the two fore feet. The 

 larger hind limbs with their stronger muscles and ligaments, would offer better 

 resistance to such predatory attacks ; and they, at any rate, have been preserved. 

 The agitation to which the body must have been subject in its course down the 

 stream, and before it finally sunk and settled out of sight, would be attended, after 

 a certain amount of decomposition of the flesh, ligaments, and other soft parts, with 

 such an amount of dislocation as the ribs and other parts of the vertebral column 

 exhibit along the otherwise well-preserved and completely consecutive series of the 

 bony segments, from the skull to near the end of the tail. But the oblique 

 compression of the skull, the flattening of the thorax, squeezed between the approxi- 

 mated piers of the scapular arch, attended with fracture of one of the coracoids, 

 and other indications in the rest of the trunk, plainly bespeak the enormous pressure 

 to which the fossil has been subject after its imbedding, and which must have been 

 attended with stiU more injury and destructive obliteration of anatomical characters 

 had it not been for the surrounding uniform support afforded by the matrix, 

 compactly hardened around the petrified skeleton before those cosmical movements 

 commenced to which the change in the position of the old Liassic sea-bottom has 

 been due. 



