238 POPULAR SCIENCE MONTHLY. 



Leaving this parental order, in the Permian and Lower Trias, we 

 first see in the older offspring, the Anomodontia, reptiles of varied size 

 and description, carnivorous and herbivorous in habit, most abundantly 

 found in South Africa, in Asia and in Europe, and not at all as yet in 

 America, either North or South. The high degree of fitness for dif- 

 ferent habits, or radiation, of the Anomodonts is distinguished from 

 that of any other reptiles at any time by its numerous analogies to the 

 radiation of the mammals, namely, into very large and very small 

 forms, into carnivorous and herbivorous, into terrestrial and possibly 

 into aquatic types ; in fact, some of these animals, if seen on land to-day 

 might readily be mistaken for mammals. 



The second offspring of the Cotylosauria, on the contrary, the Diap- 

 tosauria, are essentially and unmistakably saurians; that is, if seen 

 about us to-day they would undoubtedly at first be described as lizards. 

 They were still more broadly cosmopolitan in range, being scattered 

 over both Americas (Pelycosauria, Proganosauria), Europe (Protoro- 

 sauria, Rhynchosauria), Asia (Rhynchosauria) and Africa (Progano- 

 sauria, Rhynchosauria). They are also found highly diversified in 

 type, but all their analogies of fitness are with the reptiles and not 

 with the mammals. It is of prime importance that more of these 

 diaptosaurs be found, and that those already known in the museums 

 should be more critically examined. What we already know, however, 

 enables us to establish the following facts : first, that the parentage of 

 these animals is more probably among the cotylosaurs than among the 

 anomodonts, and second that already in the Permian they had formed 

 a sufficiently large number of branches to be regarded as a fully evolved 

 radiation. 



Problem of the Adaptation of the Mesozoic Reptiles. 



In the Triassic the offspring of the anomodonts and of the diapto- 

 saurs appear as the third generation from the cotylosaurs. 



The recurrent difficulty arises that the actual points of contact or 

 transition from the anomodonts are wanting, and we must continue 

 to reason by the ideal reconstruction of the hypothetical linking forms. 

 Such reasoning connects the Testudinata (turtles and tortoises), the 

 Sauropterygia, or marine plesiosaurs, and, singularly enough, our own 

 ancestors, the primordial mammals, with the group of anomodonts and 

 not at all with that of the diaptosaurs. Here in the Upper Permian 

 and Lower Trias we must await both discovery and the closest critical 

 analysis, but if this still hypothetical affiliation be confirmed by dis- 

 covery, as I personally am sanguine it will be, then it will be true to 

 say that the mammals, and hence man, are much more nearly affiliated 

 to the anomodonts than to either the lizards or snakes, which are 

 both on the great Diaptosaur branch. Our presence on the great 

 Anomodont branch and remoteness from the creeping and crawling 



