OUR FACE FROM FISH TO MAN 



animals with sharp cusps and blades on their 

 tritubercular or triangular upper molar teeth. 

 In these little Cretaceous placentals the skull and 

 teeth were in many ways like those of certain 

 existing insectivorous mammals, such as the tenrec 

 of Madagascar. 



All the evidence available from several sources 

 indicates that the remote ancestors of the line leading 

 to all the higher mammals, including man, were small 

 long-snouted mammals, of insectivorous habits and 

 not unlike some of the smaller opossums and insecti- 

 vores in the general appearance of the head. 



BETTER FACES COME IN WITH LIFE IN THE 

 TREE-TOPS 



Immediately upon the close of the Age of 



Reptiles the mammals appear in certain regions in 



North America and Europe in great numbers and 



variety. Palaeontologists think it probable that 



they came from Asia, possibly by way of the 



Behring Straits land-bridge. In the Basal Eocene 



or Paleocene rocks of New Mexico and a few other 



places have been found thousands of fragments 



of fossilized jaws and teeth and several incomplete 



skeletons of mammals, ranging in size from mice 



52 



