i 4 2 POPULAR SCIENCE MONTHLY. 



In 1818 the first fossil skeleton found in the valley was discovered 

 at New Windsor, Conn., and later, just before the civil war, another 

 was brought to light at Springfield, Mass. These, while fragmentary, 

 were recognized to be reptilian in character, and when the latter speci- 

 men came to light it at once cast a grave doubt upon the correctness of 

 the accepted interpretations. Hitchcock himself speaks of these re- 

 mains as being ' those of fair representatives of the creatures which 

 made the tracks.' 



It was not until nearly the last decade of the nineteenth century 

 that further excavations at New Windsor, which resulted in the finding 

 of two more specimens, enabled Professor Marsh, of Yale University, 

 to restore the creature and to give us an adequate knowledge of its 

 organization and affinities and thus to furnish the first true key to the 

 correct interpretation of the footprints. Further discoveries abroad, 

 but more especially in our own great west, have given us a very com- 

 plete knowledge of the magnificent race of reptiles to which the Con- 

 necticut Valley forms belong. 



During the Mesozoic age, comparable to the medieval times in 

 human history, reptiles were the dominant forms; they occupied the 

 places in the economy of nature to-day taken by the birds and beasts, 

 both animal and plant feeding, as well as by the whales and other 

 denizens of the air, earth and sea; but among the great reptilian 

 assemblage none were more varied in size, aspect and habits than the 

 dinosaurs or terrible lizards, at that time the peers of the animal 

 realm. These creatures are first known from the rocks of the Triassic, 

 the earliest of the three periods into which the Mesozoic age is divided, 

 reaching their millennium as a race during the close of the second or 

 Jurassic period, at which time they attained their greatest profusion 

 in numbers and their bighest development in point of size. In the 

 strata formed toward the close of the Cretaceous, or final period, the 

 dinosaurs reach their maximum of specialization, developing forms 

 among the most weird, grotesque, as well as the most terrifying, the 

 world has ever known. This marks the decadence of the race, the 

 prelude to its extinction, for in the immediately overlying rocks of the 

 Tertiary period not the least vestige of a dinosaur has been found. 



At least three great orders of Dinosauria are recognized, of which 

 two, embracing the land forms, were represented in the footprint fauna, 

 while of the third, gigantic quadrupeds, whose vast bulk has won for 

 them the name of Cetiosauria or whale lizards, plant feeding and 

 semi, if not wholly, aquatic in their habits, there, is not a trace. 



The remaining orders were sharply differentiated in their habits 

 of feeding, the one being carnivorous, the other herbivorous, in diet; 

 and while the more primitive members of both orders were quite 

 similar, such is the influence of habit upon a race that their evolution 



