

HISTORY OF WHALES 



5 1 



arctirostris (Cabrera, 192.6)) 

 Squalodon bariense (Dal Piaz, 191 6), and 

 Squalodon bellunense (Dal Piaz, 191 6). 

 Porpoises of this type have been called 

 squalodonts because of the general simi- 



teeth of similar shape and skulls of an 

 antecedent construction. It is obvious 

 that the narial passages have moved 

 farther back than in their Eocene prede- 

 cessors; the nasal bones are very much 





Arit. n. 



Ap.max. 



S. or. pr. 



S.'oc. 



Squalodon calv:rtmsis 



Ex. oc. 



S. or. pr. 



S.oc. 



Prosqualodon australis 

 Fig. 5. Dorsal Views of Skulls 

 Prosqualodon australis, Lower Miocene, Patagonia. Squalodon calvertensis, Middle Miocene, Maryland 



larity between their teeth and those of 

 sharks; but the teeth of squalodonts, 

 unlike those of sharks, have two or three 

 roots . These squalodonts must trace their 

 ancestry back to unknown small archaic 

 toothed whales of the Eocene, having 



atrophied and are pressed into the frontals 

 on the forewall of the braincase. In 

 addition to other peculiarities possessed 

 by these skulls, there are two small 

 apertures on the anterior wall of the 

 braincase for the passage of olfactory 



