76 ANIMALS OF THE PAST 



because, as indicated by the limited area for the attach- 

 ment of wing muscles, its flight was performed with 

 very small expenditure of power : thus while the model 

 aeroplane, the first that actually flew, required one and 

 one-half horse power for its thirty pounds weight, 

 Pteranodon, it is estimated, used but thirty-six thou- 

 sandths of a horse power for the same purpose. 



One feature of Pteranodon, the extraordinary crest 

 shown in the picture, has been the cause of much argu- 

 ment; for a time it was even a moot question whether 

 or not he had one. Professor Marsh said he did. Profes- 

 sor Williston as vigorously said he didn't, and both 

 were right; some had huge crests, some had none, and 

 why they did or didn't no one really knows. Much 

 ink and paper have been expended in expounding 

 theories in regard to the use of the crest, the writers 

 apparently forgetting that it was quite as often absent 

 as present; furthermore that animals have an unfortu- 

 nate habit of doing things that are theoretically impos- 

 sible and are often provided with appendages of no 

 apparent use. To add a few more theories, it is here 

 suggested that the presence or absence of a crest was a 

 sexual distinction,, or that it may have served as a 

 counterpoise to the long beak; finally that it does not 

 seem at all necessary that it should have served any 

 useful purpose whatever, being a danger signal that the 

 day of the pterodactyl was drawing to a close. > 



Not the least interesting of the problems concerning 

 Pteranodon and other Pterodactyls is how did he carry 

 himself on land, and having come to earth — or sea — 

 how did he get under way again, what did he do with 



'Professor Beecher considers that the development of spines or of 

 superfluous crests and bosses is an indication of deterioration and indi- 

 cates approaching extinction. 



