528 Evolution and Distribution of Fishes 



The origin, at a still more remote period, of the Beryc- 

 idae, is traced to the time when extensive lake and river 

 deposits were being laid down during mid and late Cre- 

 taceous time in the Judith River and Laramie epochs. So 

 "all present evidence points to origin of the Acanthopter- 

 ygii in freshwater areas of Comanchean age, and over 

 the central part of the N. American continent." 



A history of geologic conditions as revealed in distri- 

 bution of the Siluridae fortifies the contention above ac- 

 cepted that the central part of the N. American continent 

 was a great and fairly safe evolutionary centre for fishes 

 during Cretaceo-Eocene time. Partial evidence is furnished 

 by the Cyprinidae that are next studied, and are shown to 

 agree with the above, from the geographic and geologic 

 standpoints. Like agreement is shown by the Characin- 

 idae, except that the earliest ancestors seem to have started 

 in the extreme south, or even in northern Archenchelis, 

 and at such a time that only late and slight contact was made 

 with Africa, but none still later with Asia. The known 

 facts all indicate that the family branched off from an 

 allied malacopterous ancestry during Cretaceo-Eocene time. 

 So only in late Eocene or in Oligocene time did species reach 

 and spread in Africa, before sundering of the Americo- 

 African or South Atlantis bridge. 



The Cyprinodontidae, Hyodontidae, and Osteoglos- 

 sidae along with a few related families, all serve to con- 

 firm, by their distributional aflSnities, the above fundamental 

 geologic and geographic relationships from Cretaceous time 

 onward. 



Chapter 15. Fishes in relation to a South Atlantic or 

 Antarctica Continent. 



The writer here restricts attention mainly to the teleo- 

 stean families Galaxidae, Aplochitonidae, Symbranchidae, 

 and Amphipnoidae, that all suggest a peculiar distribution 

 over southern continental and island centres. Regarding 

 the two latter families their evolution in Africa, and sub- 

 sequent westward migration into Brazil, also eastward to 

 India and even into Australia and Tasmania is accepted. 



