^52 



THE AMERICAX MUSEUM JOURXAL 



which sei-\-ed, presumably, to enable the crea- 

 ture to cling to trees or rocks, or to hang from 

 cliffs or boughs when resting. 



The head is converted into a great vertical 

 fin, used no doubt in dii'ecting the flight; the 

 huge, straight, compressed bill in front, and a 

 great crest projecting backward from the 

 occiput to balance it. The hind legs are long 

 but not very stout, and the tail is reduced to a 

 mere rudiment. The body is disproportion- 

 ately small, smaller than in most large birds, 

 and the bones are hollow shells scarcely 

 thicker than a visiting card. As a conse- 

 quence they are crushed completely flat in 

 fossil skeletons, and the true forms and rela- 

 tions are very difficult to reconstruct. 



So far as has been made out by studies of 

 palaeontologists and aeronautical experts,i 

 the pteranodons, while much more specialized 

 for soaring flight than are any modern birds, 

 were more limited in their movements. They 

 were incapable of the poise-flapping and 

 plunging dive so characteristic of the king- 

 fisher; the wing muscles were too weak for 

 the first movement, and inability to fold the 

 wings backward prevented the headlong dive. 

 Their construction was too delicate to allow 

 of sudden changes of speed. It is not clear 

 that they could venture to dive at all, in view 

 of the apparent difficulty they would have in 

 rising from the water, save in calm weather. 

 Yet there is no doubt that they were accus- 

 tomed to fly far out at sea, for their remains 

 are chiefly found in the chalk beds of western 

 Kansas, deposited far out in the great interior 

 sea of the Cretaceous period, over a hundred 

 miles from the nearest shore line at that time. 

 They are supposed to have fed chiefly upon 



' See especially articles in the Aeronautical Journal, 

 October, 1914, by Dr. E. H. Hankin, Prof. D. M. S. 

 Watson, and Mr. G. Howard Short. 



fish, which the}' might obtain by skimming 

 at high speed close to the water and darting 

 the great bill down to pick up objects close 

 beneath the surface. In view of the extreme 

 lightness of the body and hoUowness of the 

 bones, it is somewhat surprising that skele- 

 tons are ever found in these offshore chalk 

 formations. One would rather expect that 

 they would float upon the surface until, if not 

 devoured, they disintegrated and dropped 

 apart, and that the bones would always be 

 found scattered over the bottom, as indeed 

 they generally are. Possibly the occurrence 

 of associated skeletons is to be explained as 

 due to the animal having been seized by a 

 marine reptile or fish and dragged down into 

 deep water, causing the air-filled bones to 

 collapse and the carca.ss thereby to become 

 water-logged. If its captor then dropped it by 

 accident or was tempted by some more allur- 

 ing prey, the pteranodon, or what was left of 

 it, might sink rapidly down to the bottom and 

 be buried under the soft ooze. 



On land these animals must have been 

 singularl}' awkward and inept. They might 

 rest upon the knuckle joints of the flexed 

 wings, but could not walk upon them, since 

 the shoulder and elbow joints did not permit 

 of any fore-and-aft movement. They could 

 not fold the wings backward and walk upon 

 the hind limbs, and if they were able to walk 

 upright upon the hind limbs at all, which is 

 doubted by the best authorities, it must have 

 been with the wings uplifted and flexed in the 

 middle in a very singular pose, difficult to 

 balance properly, if indeed it was possible. 

 Nests or roosting places of some sort they 

 must have had, but of these and of the birth 

 or early development of the young nothing is 

 known, and a wide field is left for conjecture 

 as to the life and habits of these strangest of 

 extinct animals.' 



