W. D. Matthew— Fossil Vertebrates. 209 



Art. XVI. — Fossil Vertebrates and the Cretaceous-Ter- 

 tiary Problem; by W. D. Matthew. 



Eecent contributions to Science by Professor Schu- 

 chert, Dr. Cross and Dr. Knowlton^ have brought up 

 again the old controversy as to the dividing line between 

 Cretaceous and Tertiary formations in America. As the 

 fossil vertebrate faunas afford an important part of the 

 evidence on this dispute, very considerably increased 

 by collecting and research in recent years, I have been 

 asked to give a brief resume of this evidence and of the 

 conclusions to which my interpretation of it has led. 



Recent Additions to the Vertehrate Evidence. 



When the problem was discussed in 1913 by the 

 Geological Society of America I contributed a paper^ 

 setting forth the data up to date especially as regarded 

 the Paleocene formation. Since then considerable 

 advances have been made in the study of the Vertebrata. 

 I have been engaged jointly with Mr. Walter Granger 

 upon a revision of the Lower Eocene mammals, now 

 mostly published, and of the Paleocene mannnals of New 

 Mexico, still in progress.^ Mr. Gilmore has contributed 

 two most valuable memoirs, one on the vertebrates of the 

 Ojo Alamo formation, the other upon the reptiles of the 

 Puerco and Torre j on formations of New Mexico.^ A 

 very large amount of new information is now at hand as 

 to the faunas of the late Cretaceous vertebrates of 

 Alberta, partly in the published contributions by the late 

 Mr. Lambe,^ Mr. Barnum Brown,^ Professor Osborn^ and 



^Schuchert, 1921, Science, 53, p. 45, Jan. 14; Cross, 1921, ibid., p. 304, 

 April 1; Knowlton, 1921, ibid., p. 307, April 1. 



^ Evidence of the Paleocene Vertebrate Fauna on the Cretaceotis Tertiary 

 problem. Bull. Geol. Soc. Am., 25, pp. 381-402. 



^ See various articles by Granger, Sinclair and the writer, in Bull. Am. Mus. 

 Nat. Hist., 1914-1919. 



* Gilmore, 1916, U. S. G. S. Prof. Pap. 98 Q, pp. 279-302; 1919, idem, Prof. 

 Pap. 119, pp. 1-68. 



^Lambe, 1914, Ottawa Naturalist, vol. 27, pp. 130-135, 145-155; vol. 28, 

 pp. 13-20; 1915, Can. Geol. Sur., Mus. Bull. No. 12, pp. 1-49; 1917, Ottawa 

 Nat., vol. 30, pp. 117-123, vol. 31, pp. 65-73 ; Can. Geol. Sur., Mem. No. 100, 

 pp. 1-84; 1920, Can. Geol. Surv., Mem. No. 129, pp. 1-79. 



« Brown, 1914, Bull. Am. Mus. Nat. Hist., vol. 33, pp. 539-548, 549-558, 559- 

 565, 567-580; 1916, idem, vol. 35, pp. 701-708, 709-716; 1917, idem, vol. 37, 

 pp. 281-306. 



' Osborn, 1917, Bull. Am. Mus. Nat. Hist., vol. 35, pp. 733-771. 



