TOOTHED BIRDS. 



233 



Sub-Class II. TOOTHED BIRDS (Odontornithes). 



These strange fossil birds 

 were discovered in the creta- 

 ceous beds of this country by 

 Professor Marsh. Their rep- 

 tilian and fish-like characteris- 

 tics are seen in the vertebrae, 

 which are biconcave. The jaws, 

 long and slender, were armed 

 with teeth .(Fig- 274) placed in 

 sockets as are those of the croc- 

 odile. Some were fliers and oth- 

 ers had rudimentary wings. The 

 Hesperornis was a large aquatic 

 bird about six feet in height. 

 Its jaws were supplied with 

 teeth set in grooves, the wings 

 were useless and rudimentary, 

 while the feet were like those 



FlG. 274. Bird with teeth, showing jaw with teeth, the sockets, a tooth 

 enlarged, and section of the backbone. (After Marsh.) 



