APPENDIX B 



The Chronology of Whales 

 from 60j000j000 b.c to ip;o a.d. 



THE past history of the whales themselves presents us with many 

 fascinating and quite unexpected surprises. The difficulties pre- 

 sented by time, on the geologic or cosmic scale, to creatures such as we 

 with our very Hmited span of Hfe have already been mentioned on two 

 separate occasions, first, with regard to our own paltry history and, sec- 

 ond, with respect to the age of the rocks comprising the surface of our 

 earth. Sixty milHon years are really quite incomprehensible to us; a mere 

 million of anything is almost beyond our reasoning. 



Whales are rather primitive animals, but they are mammals, and these 

 are the least primitive of Uving things. Their origins obviously were in 

 the dim past, but when we come to plot all that we have discovered of 

 that past, in the form of fossils, we find that it extends back hardly at all 

 into the vast sweep of our planet's history. The earUest whale that we 

 know definitely is not older than some fifty milhons of years, and this 

 is comparatively young for mammals as a whole. 



One most primitive-appearing type of whale, the gray whale, is 

 not known from before the current ice age, and four of the existing 

 groups — the platanistids, the beaked whales, the sperms, and the dol- 

 phins — appear simultaneously only some twenty million years ago. 

 These, moreover, are the oldest of existing whales. On the whole, the 

 baleen whales appear to be the most recently developed, though the 

 primitive forms known as Cetotheres have a venerable history, as shown 

 on the accompanying chart. The majority of toothed whales, and even 

 the extinct forms, appear more recently. Only one group, known as the 

 Agorophidae, are of comparatively great age — as great, in fact, as the 

 earliest of the ancient whales, the Zeuglodonts. There is some doubt as to 

 the true position of these agorophids, and there is considerable mystery 

 involved in the complete absence of any intermediate types, either in time 



