282 



THE ANIMALS AND MAN 



species of all the great groups from simplest to higher are 

 living today. Most of these species are however modem 

 in their origin. The original or first species in all the great 



Fig. 153. Skeleton of Hesperornis regalis, the (iiunl TiMiilud Kinl (.t 

 the Kansas Cretaceous. (In the American Museum of Natural Hi.ston,-; 

 after Sternberg.) 



groups are gone; and some whole families and orders of 

 species are extinct. For example in the class of reptiles 

 there existed in the Mesozoic era many enormous kinds 



