n8 EVOLUTION IN THE PAST 



may not have been averse to flesh when obtainable without 

 risk, but their staple fare consisted probably of vegetables. 

 CREDONTS Small, long-tailed creatures of more bear-like appearance 

 were also abroad. These possessed teeth of a trenchant type, 

 showing that flesh-eating had become a habit (Arctocyori). 

 In the shape of the skull, and the claw-like termination of 

 the feet, they were also developing in the direction of true 

 carnivores. Some mammals, it is clear, had passed out of the 

 Age of Innocence. 



These primitive flesh-eaters are classed as Creodonts 

 (" flesh - teeth ") ; but their close relationship with the 

 " knuckle- jointed " vegetarians was attested by many ana- 

 tomical features. 



Mammal life was thus in process of important develop- 

 ments, foreshadowing the two great Orders of ungulates or 

 hoofed animals, and carnivores. Nor was the promise of 

 future development limited to those directions. Other 

 contemporary animals seem to have been setting out to 

 EDENTATES found the Edentates the somnolent Order which com- 

 prises sloths, ant-eaters, and armadillos. Edentates (" tooth- 

 less ") is not altogether a happy name ; for many edentates 

 possess at least cheek teeth. Teeth, however, are not a 

 strong point with any living members of the Order. 



These Edentate pioneers known as Ganodonts were 

 about the size of small dogs ; were well supplied with teeth ; 

 and were probably not so drowsy as their present repre- 

 sentatives (Hemiganus). Their dentition became somewhat 

 reduced even during the early part of the Period. In 

 the course of time teeth, and it may be added toes and tails, 

 have frequently been in the melting-pot of Evolution ; and 

 edentates were destined to undergo great dental suppressions 

 in times to come. 



INSECTIVORES Other developments in the mammal world were also taking 

 place Insectivores the Order which comprises shrews, 

 moles, and hedgehogs had been foreshadowed so far back 

 as the Jurassic Period, at least in marsupial form. In early 

 Eocene times shrew-like creatures of higher rank than 

 marsupials were certainly poking about in the thick grasses 

 (Adiposorex^). 



