632 DR. R. BROOM ON 



l)ipe(lal animal before it flew, or if it only hopped after the wing 

 had become specialised- I am strongly of the opinion that it was a 

 hopping animal first, and that the metatarsus became strengthened 

 to support the weight of the body entirely boi'ne by the hind feet. 

 It is easy to understand a hopping animal taking to an arboreal 

 life and ultimately developing a wing out of a four-toed hand, 

 while it seems unlikely that the hind foot could ever have 

 developed by arboreal habits. It is interesting to note that 

 while the ancestor of the Pterodactyls had four toes in the manus, 

 there is very clear evidence from the skeletogenesis of the bird 

 that the latter also had a four-toed ancestor. 



A Pseudosuchian which through a bipedal habit had developed 

 a strengthened ankle-joint and a firm metatarsus, and had lost 

 the 5th digit from the manus would meet all the requirements of 

 the avian ancestor. 



We know at present too little to discuss the relationship of the 

 Pseudosuchians with Sjjhenodov and with Gnathodonts, nor can 

 Ave say whether Hoivesia and Mesosuchus should be placed with 

 the Pseudosuchians. There is evidence of a generalised Permian 

 liliynchocephaloid order which gave I'ise to the more specialised 

 Triassic groups, but at pi'esent we know too few foims and very 

 few even of these are well known, and until our knowledge has 

 much advanced it seems unwise to attempt any further classifi- 

 cation. In South Africa we can trace through the Lower Triassic 

 and Upper and Middle Permian beds forms that mny be ancestral 

 to the Pseudosuchians, and when these are better known a 

 satisfactoiy classification will be possible. 



I am much indebted to Mr. E. S. C. Dyke for the photographs 

 of Euparkeria. 



References to Literature, 



(1) E. T. Newton. — "Reptiles from the Elgin Sandstone. 



Description of two New Genera." Phil. Ti-ans. vol. 185, 

 1894, p. 573. 



(2) G. A. BouLENGER. — "On Reptilian Remains from the Trias 



of Elgin." Phil Trans, vol. 196 b, 1903, p. 175. 



(3) A. S. WooBWARD. — " On a new Dinosaurian Reptile (Sclero- 



mochlus taylori) from the Trias of Lossiemouth, Elain." 

 Q. J. G. S. vol. Ixiii. 1907, p. 140. 



(4) F. V. HuENE. — "Die Dinosaurier der Europiiischen Trias- 



formation." Geol. u. Pal. Abhand., Jena, 1907. 



(5) D. M. S. Watson. — '^Mesosuchus hroivni, gen. et spec, nov." 



Pvec. Albany Mus. vol. ii. pt. iv. p. 296. 



(6) R. Broom. — -""Note on Mesosuchus broumi Watson, and on 



a new South- African Triassic Pseudosuchian {EiqKirkeria 

 capensis)." Rec. Albany Mus. vol. ii. pt. v. 1913, p. 394. 



A full list of other papers Avill be found in v. Huene's work. 



