HISTORICAL REVIEW OF THE LARAMIE PROBLEM. 



73 



The second paper, by Gilmore, was entitled 

 "Vertebrate faunas of the Ojo Alamo, Kirt- 

 land, and Fruitland formations." The verte- 

 brates include dinosaurs, turtles, crocodiles, 

 and fishes, and according to Gilmore they "are 

 found tlu-oughout these deposits, though they 

 appear to occur most abundantly in the Ojo 

 Alamo and the upper part of the Kirtland, 

 sparsely in and below the Farmington sand- 

 stone member of the Kirtland, and more 

 abundantly in the Fruitland." His conclu- 

 sion regarding their age was as follows: 



After a study of the material in the United States 

 National Museum collections from this area, and after 

 reviewing the literature in which specimens from tliese 

 formations have been described, I conclude that the 

 vertebrate remains from the Ojo Alamo, Kirtland, and 

 Fruitland formations show beyond all question that they 

 pertain to a fauna or faunas distinctly older than that of 

 the Lance, and that such evidence as there is contributes 

 to the support of Brown's contention that tlie Ojo Alamo 

 sandstone is synchronous with the Judith River and Belly 

 River formations as found in areas to the north. 



The third paper, by Stanton, was entitled 

 "Nonmarine Cretaceous invertebrates of the 

 San Juan Basin" and dealt mainly with 

 brackish and fresh water species from the 

 Fruitland formation, only 2 of the 27 recorded 

 species coming from the Kirtland shale and 

 none from the Ojo Alamo sandstone. A table 



giving the stratigraphic range of these forms 

 was presented and was discussed by Stanton 

 as follows: 



The distribution of the species as exhibited in the table 

 may seem at first glance to indicate that the Fruitland 

 fauna is about as closely related to the Mesaverde and 

 Judith River faunas (which are approximately contem- 

 poraneous with each other) as it is to the Lance and 

 Laramie faunas. A closer analysis of the table, however, 

 will show that most of the species occurrijig or represented 

 by related forms in the Mesaverde and Judith River are 

 long-lived brackish-water species which range at least as 

 high as the Laramie. Melania insculpta belongs to this 

 class, for like all tlie other American Cretaceous species 

 referred to Melania it is invariably associated with 

 brackish-water forms. The only two Fruitland species 

 with an outside distribution which do not elsewhere 

 range into the higher formations are Modiola laticoslata, 

 from the Mesaverde, and Goniobasis? subtortuosa. from 

 the Judith River. With fresh-water species, especially 

 those belonging to the genus Unio, the case is different. 

 The majority of the identical and closely related species 

 are found in the Laramie, the so-called "Lower Laramie" 

 of southern Wyoming, and the Lance and do not range 

 below these formations. It is my ojjinion, therefore, that 

 the invertebrate evidence as a whole favors the assign- 

 ment of the Fruitland formation to an epoch considerably 

 later than Mesaverde and Judith River and possibly some- 

 what earlier than Lance. If due weight is given to the 

 known stratigraphic relations and to the faunal evidence 

 from the underlying formations, the P'ruitlaud can hardly 

 be older than Fox Hills, and the sequence from the base of 

 the Fruitland up to the top of the Ojo Alamo, which is 

 conformable, according to Mr. Bauer, may include the 

 equivalents of everything from the Fox Hills to the Lance 

 inclusive. 



In my paper, on the "Flora of the Fruitland 

 and Kirtland formations," the flora was dis- 

 cussed as follows: 



Of the 40 forms making up the known flora of the Fruit- 

 land and Kirtland formations, 10 have been found in other 

 areas, and the list brings out the fact that no less than 15 of 

 these forms are known to occur in the Montana. A further 

 analysis of the list shows that 12 of the 15 forms occur in the 

 Vermejo formation of Colorado and New Mexico, 10 occur 

 in the Mesaverde, or rocks of about tliis age, in Wyoming 

 and elsewhere, and 6 species are common to both these 

 areas. X)n the basis of this showing the conclusion seems 

 justified, therefore, that the Fruitland and Kirtland for- 

 mations are of Montana age. 



The material in a single small collection from 

 the Ojo Alamo beils was so fragmentary that 

 it could not be identified with satisfaction. 

 Concerning it I said: 



It includes portions of a large leaf of unknown affinity, a 

 small willow-like leaf, and a large leaf that appears to be 

 an Aralia of the type of Aralia notata Lesquereux, a species 

 very abundant and widely distributed in the Fort Union 



