REVIEW OF GONDWANALAND DATA 193 



which arrived in the Oligocene. This I do not feel would at all justify 

 postulating such a land connection in Tertiary time. 



Eeview of Gondwanaland Data : Reptilian, Fish, Land Snails, 



AND Flora 



However, there is a well established tradition that there was a land 

 bridge from Africa to South America through Permian, Triassic, Juras- 

 sic, and Cretaceous time, making South America a part of the continent 

 termed Gondwanaland. Let us look at the evidence on which this is 

 based. Among other groups, it has been used to explain the distribution 

 of fresh-water fishes, land snails, mussels, crayfish, and the Glossopteris 

 flora. These are not all the groups for which it has been postulated, but 

 in these the best arguments have been built up. Vaughn's studies^ on 

 Central American invertebrate faunas yield this in regard to the connec- 

 tions of North and South America : "During Jurassic and Cretaceous 

 there was no connection between the Atlantic and Pacific oceans across 

 Central America"; and, further, but no longer quoting, during Triassic 

 and Permian there were land conditions through Mexico and Central 

 i^merica, with but one interoceanic connection in the Triassic. This 

 being the case, there w^as always open the possibility of migrations to and 

 from North America during almost all of the period postulated for 

 Gondwanaland. 



First let us look at the reptiles, of which South America has yielded 

 but a scant supply. However, there are three genera of theropod and 

 three of sauropod dinosaurs which LulP in his distribution of dinosaurs 

 has piloted via Gondwanaland. Of the theropods two genera are peculiar 

 to South America and the third is Megalosaurus, also reported from Aus- 

 tralia, India, Germany, England, etcetera; but this genus, is based on 

 fragmentary material and I am by no means convinced of the correctness 

 of the assignment. Of the sauropods, two again are- peculiar to South 

 America and the third is Titanosaurus of Africa, India, England, and 

 France. The genus is based on two caudals from India, and the figures 

 and description make the South American fragments fully as close to 

 some of the North American sauropods. At this time North America 

 had large numbers of both Theropoda and Sauropoda similar to the 

 South American forms and the path was open. 



In North America we have some of the earliest reptiles, and it is of 

 interest to take such a sketch classification as Watson's'^ and consider 

 their distribution. Cotylosauria occur in the Upper Coal Measures and 



= Bull. 103, U. S. National Museum, 1019, p. 611. 

 " Am. .lour. Scl., vol, 29, 1910, p, 1. 

 ^rroc. Zool. Soc. London, 1917, p. 167. 



XIII— Hull. Geol. Soc. A.m., Vol. 32, 1920 



