OSTEOLOGY OF IHE AKMOKED DINOSAUEIA. '25 



In this quarry the bones are for the most part found in a very hard layer of 

 sandstone/ though they occasionally extend down for a short distance into the 

 underlying clays. The bone-bearuig horizon is not more than 3 feet thick vertically 

 and has been worked over only a few hundred square feet, yet a wealth oi material 

 has been found, as evidenced by the f aunal list given below, which does not begin 

 to represent the number of individuals recovered. 



According to Hatcher = "The bone-bearing stratum is about 150 feet above the 

 red Triassic sandstones." He also says: "That the lowermost dinosaur beds of Gar- 

 den Park are of an earlier age than those of Como Bluff." 



Plan of work. — The fossil bones lay buried in a thick stratum of heavily bedded 

 sandstone. Not only was the stone extremely hard, but it was also considerably 

 fractured, both vertically and horizontally, in such manner as to greatly increase 

 the difficulties encountered in properly taking up the bones. Mr. Felch, however, 

 overcame these difficulties in a most commendable manner. The specimens were 

 quarried out in laige blocks of stone, the contained fossils thus being retained in 

 their original relative positions. Each articulated or partially articulated skeleton 

 was given a number (for example, the type of Stegosaurus stenops was designated by 

 the field number "Sk. 11 "). The sksletoii was divided into irregular-sized groups, 

 each group being indicated by a number, as Gi. 1, Gr. 2, etc. The pieces of stone 

 comprising the different groups were lettered, each group beginning with A and 

 conthiuing alphabetically. Tlie skeleton, group, and block designations were 

 painted on. the stone, so that, aided by the rough sketch diagrams made and prop- 

 erly marked at the same time, the work of assembling the blocks in the laboratory 

 was reduced to a minimum. Considering the early date of this work, which was 

 before the development of modern field methods, the painstaking care and ingenuity 

 displayed by Mr. Felch in collecting tliis difficult material with such success is most 

 remarkable. 



The list that follows shows the fauna of Quarry No. 1 . 



DiNosAxmiA : Dinosaueia — Continued. 



* Ceratosaurus nasicornis Marsh. Laosaurus gracilis Marsh. 

 *Lahrosaurusferox Marsh. Camptosaurus medius Marsh. 

 *Stegosaurus stenops Marsh. Crocodilia: 



Stegosaurus armatus Marsh. GoniopTiolis sp. 



* Morosaurus agilisM.axs\\. Chelonia: 

 *Haplocant7iosaurus priscus Hatcher. *Probaena sculpta Hay. 

 *Haplocanthosaurus utterhacki Ghjptops plicatulus (Cope) . 



Hatcher. Pisces : 

 *Diplodocus longus Marsh. * Geratodus giintheri Marsh 



Brontosaurus sp . Geratodus sp . 



AUosaurus fragilis Marsh. Mammalia: 

 Gcdurus agilis Marsh. Dryolestes gracilis Marsh. 



[Those marked with an asterisk (*) represent typc-specim'-ns.l 



1 Dr. George P. Merrill has kindly made a microscopic examination of the sandstone in which the bones were found, and 

 his conclusions are as follows: 



"The sandstone consists mainly of quartz granules with a little feklsimr and flecks of brown mica, with a relatively large 

 amount of interstitial calcite which serves as a cement. The grains of sand are not greatly rounded, in some cases are angular, 

 indicating that they have not been subjected to much wear. I am inclined to regard them as of river, lake, or estuary origin 

 rather than consolidated beach sands which would, under ordinary conditions, show greater signs of wear." 



2 .\nnals of the Carnegie Museum, vol. 1 , 1901 . p. 336. 



