2 PEOCEEDINGS OF THE N"ATIO]SrAL MUSEUM vol.73 



The unique geographical occurrence of this Oregon fossil in con- 

 junction with its intermediate geological position appears to justify 

 its description as a new species, and the specific name oregonensis is 

 proposed for its reception. As a matter of expediency awaiting the 

 discovery of more diagnostic materials, this species is tentatively 

 assigned to the genus Pteranodon. That it may pertain to a new 

 genus is a fact fully recognized but one that can only be determined 

 by the discovery of more complete specimens. 



PTERANODON (?) OREGONENSIS, new species 



Type. — Consists of a nearly complete left humerus, two coossified 

 dorsal vertebrae and the articular end of an undetermined bone. 

 Collected by E. L. Packard, 1927. 



Type locality. — "Mitchell Quadrangle, Wheeler County, Oreg., 

 S. E. 14 sec. 36, T. 26 S., K. 21 E. About 200 feet above gorge of a 

 small east gulley leading into Nelson Creek about 14 rail© above its 

 mouth, not more than 200 feet from southward bend in Nelson Creek 

 Road after it reaches the flat." 



Geological occurrence. — Upper Chico, or Lower Horsetown, Cre- 

 taceous. 



Description. — The few bones preserved of this specimen are remark- 

 able on account of their uncrushed preservation, an unusual condition 

 in flying reptiles. On account of the fragile hollow structure of the 

 bones of the pterosaurs, and especially those from the Niobrara Chalk, 

 they are usually much flattened, "with their natural configuration so 

 altered as to leave one in doubt as to their original form. Fortu- 

 nately, these bones have not suffered in this respect, although impor- 

 tant parts of certain of the processes have been lost either through 

 erosion al agencies before the specimen was discovered or have been 

 destroyed by subsequent attempts at preparation. 



When the humerus came into my hands it was in two pieces, and 

 although the two broken surfaces appear to show contact at the 

 middle of the shaft and the external contours seem to be in accord 

 on all sides, a slight doubt exists as to their being properly united. 

 Professor Packard, however, assures me that there can be no doubt of 

 their belonging together. 



A critical comparison of the humerus with the humeri of other 

 American pterosaurs is rendered quite unsatisfactory due to the 

 crushed and flattened condition of all of the Niobrara fossils. Eaton ^ 

 has called attention to this flattening as follows: 



The vagaries of form assumed by the humerus [in Pteranodon] under pres- 

 sure in the matrix are very surprising, the first result of this perplexing situa- 

 tion being that almost every humerus in the collection seems to represent a 



» Eaton, G. F., Memoirs Conn. Acad. Arts and Sci., vol. 2, 1910, pp. 28-29. 



