300 On the Skeleton of Nyctodactyhis, with Eestoration 



Coracoicl and scapula coossified (imperfectly so in another specimen of 

 the same species), the former articulating by the usual saddle-shaped 

 joint with the sternum, the latter terminating in a free, spatulate ex- 

 tremity, without union with the notarium. Humerus with its deltoid 

 process very long, helmet-shaped and with a constricted neck; remaining 

 bones of the extremities very much as they have been described in Or- 

 nithostoma. 



In the restoration given herewith, in which the measurements have 

 been made with great care by myself, one is struck with amazement at 

 the extraordinary development of the head and wings as compared with 

 the rest of the skeleton. While the wings gave a spread of very nearly 

 eight feet, the body proper was less than four inches in diameter and not 

 more than six in length, exclusive of the small tail; the pelvis is less 

 than five-eighths of an inch in diameter at its outlet, and the entire body 

 was smaller than one's closed hand! One wonders where sufficient 

 surface was presented for the attachment of the strong muscles neces- 

 sary for the control of the wings. When it is remembered, however, 

 that even the largest bones of the skeleton had walls less than a milli- 

 meter in thickness, and that many of the smaller ones were almost like 

 cylinders of writing paper, he will perceive that, notwithstanding the 

 extraordinary development of the anterior extremities and head, the 

 creature, when alive, must have Aveighed but little, I very much doubt 

 whether the living animal attained a weight of five pounds. How and 

 Avhere such creatures could have reared their young is to me inexplica- 

 ble. No evidences have been found in the many specimens of these 

 animals that have been exhumed from the Kansas chalk that they were 

 viviparous, and from the high degree of ossification of the bones in the 

 adult, it is quite sure that the foetus must have had a bony skeleton, 

 and that evidences of such would have been forthcoming before now 

 had the young really been born alive, unless, indeed, in the immature 

 condition of marsupials. If eggs were laid, they could not have been 

 more than a centimeter in diameter, and even if much elongated to ac- 

 commodate the long bones of the wings, the newly hatched pterodactyl 

 could hardly have been of sufficient size to have cared for itself. 



A number of other interesting conclusions — or speculations — are sug- 

 gested by the present specimen. The acetabulum is placed far back, 

 nearly over the edge of the sacrum; so far back, indeed, that it would 

 have been impossible for the knees to have met in the middle, when the 

 thighs were flexed to a right angle. Furthermore, the femora have a pe- 

 culiar mesial convexity, whereby the tibias were directed at a marked an- 

 gle outward, with the thigh in the normal human position. The convexity 



