SlTER-ORDEU II 



ODOXTOILMAK 



•2<;: 



in Hesperornis the extremely long premaxillae are toothless. In the mandible 

 the teeth extend to the tip. Hesperornis was a flightless and highly specials 

 diving bird of great size, having the wing represented by the humerus only. 

 The coracoid is short and wide, but the clavicle articulates with the inner side 

 of the head as is customary among birds. 1 The pelvis is greatly compressed, 

 the femora short and massive, the patella enormous and functioning as 

 cnemial process, the tibiae hollow. The outer digit of the four-toed foot is 

 much the largest, being nearly twice the length of the third digit; the toes 

 appear to have been lobed, and the tarsi were directed outwards from the sides 

 of the body and not downwards as in modern birds. 



Enaliornis, from the Cambridge Greensand, has been considered as a related 

 form, and another genus, Baptornis, also occurs in the Kansas Cretaceous. 



Super-Order 2. ODONTORMAE. 



Birds with teeth in separate sockets and with slightly amphicoelous vertebrae. 

 Palatal structure unknown, but the quadrate 1ms but a single head. 



The order Ichthyornithes is best known by Ichthyornis victor, Marsh (Figs 



369-371), a bird about the size of a pigeon, 

 from the Cretaceous of Kansas. The deeply 

 keeled sternum and the humerus indicate a 

 bird of powerful flight, but as in Hesperornis 

 and most Dromaeognathae, the component bones 

 of the pelvis are posteriorly free. Aj in 

 Hesperornis, the teeth of the separated halves 



Fig, 370. 



Ichthyornis di&par, Marsh. V \ 

 Kansas. Mandible, 8/4 (after Marsh). 



■-. r.-^-tr- ■ 



Fig. 369. 



yornis victor, Marsh. Uppei Cretaceous; Kansas. 

 Restoration of skeleton, ' 2 (after Marsh). 



Fig. 371. 



Tcht par, Marsh. Lateral (.!). and 



anterior (/•'). aspeel of cervical vertebra, -j 

 (after Mai sh 



of the lower mandible extend the full length of the dentary, while in the 

 upper jaw they were confined to the maxilla. 



1 This is quite different from what is shown in Professor Marsh's figure, but a specimen in tin- 

 Unite' I States National Museum shows that in his specimens the clavicles were slightly imperfect. 

 - Marsh, 0. C. Odontoraithes, etc. Washington, 1880. 



