396 W. D. MATTHEW THE CRETACEOVS-TERTIARY PROBLEM 



SPARXACIAX AXD YPRESIAX EQUIVALENT TO WASATCH 



The London Clay, Argiles plastiques of the Paris basin, and equiva- 

 lent formations in Belgium and elsewhere contain the Cori/phodori fauna, 

 which extends through our Lower Eocene or AVasatch faunae. The older 

 part (Sparnacian) isi probably equivalent to the Gray Bull or Systemodon 

 Zone of the Wasatch, marked by the sudden appearance of Conjplwdon, 

 PnUvoniciis, Eoliippus, Pachi/a'na. The newer part (Ypresian) may be 

 more doubtfully compared with the upper part of our Wasatch, the Lysite 

 and Lost Cabin (Heptodou aud Lambdotherium zones), the evolution of 

 the faunae being on divergent lines, witli no new invading migrants to 

 link them together. 



TffE PUERCO HAS NO CERTAIN EQUIVALENT IN EUROPE 



It is arbitrarily correlated by Osborn with the Montian. But the only 

 mammal found in the Montian is Corypkodon from the upper beds of that 

 horizon, and this, if correctly identified, would indicate not Paleocene, but 

 Eocene age of a part of the formation. On the other hand, in the Lower 

 Landenian of later age, according to Dollo, the only recorded vertebrate 

 of any value in exact correlation is Cliampsosaurus, a characteristic Cre- 

 taceous-Paleocene genus. Dollo, however, correlates the horizon as Lower 

 Eocene. In view of these contradictor}^ data, and of the doubtful char- 

 acter of such slight evidence and the frequent confusion due to redeposit 

 in these scattered littoral formations, it seems better to leave the ^fontian 

 problem for our European confreres to solve and content ourselves with 

 the reasonably certain data. 



THE LANCE IS EQUALLY DIFFICULT TO COR RE [.ATE 



There are no European formations of corresponding facies in the late 

 Cretaceous. Dinosaurs are found in the later Cretacic of Europe at least 

 as late as the Maestrichtian (^ Upper Senonian or Danian), but not suffi- 

 ciently abundant or complete to afford correlation data. The Gosau for- 

 mation is of similar facies to the Lance, but is much older — Lower Seno- 

 nian. No dinosaurs are found in the Montian or any of the European 

 formati is that are reckoned to the Tertiary. The Lance flora is shown 

 }>y Knowlton to be nearly allied to the Fort Union flora, and through 

 this to ttie Paleocene floras of Gelinden and Sezannes. But, as there are 

 no late Cretacic floras of similar type to compare it with, it is not thereby 

 shown to be post-Cretacic, as Stanton has obsened. 



