220 EXTINCT MONSTERS 



and a strongly keeled sternum for the attachment of muscles with 

 which to work its wing. It was about the size of a rock-pigeon. 

 The jaws were armed with teeth placed in distinct sockets, as in 

 some extinct reptiles. The wing bones show that it possessed 

 considerable powers of flight. Here we may note that the Cre- 

 taceous birds at present known (some twenty species or more) 

 were apparently all aquatic forms, which, of course, are most 

 likely to be preserved in marine deposits, while the Jurassic 

 Archeeopteryx was a land bird. 



Eemains of Cretaceous birds were first found in the Upper 

 Greensand of Cambridge, and on these bones the genus Enaliornis 

 has been founded. In its head and neck it resembled the divers. 



Several portions of fossil birds have been discovered in the 

 London Clay deposit of the Isle of Sheppey. One of these, the 

 Dasornis, represented by a single skull, was as large as an ostrich, 

 and probably closely related to that bird. Another, the Argillornis, 

 rivalled the albatross in size. A third, the Odontopteryx (toothed 

 bird), has a powerful serrated bill, well adapted for seizing its 

 fishy prey. In the same case in the Natural History Museum 

 may be seen casts of the limb-bones of a large bird, the 

 Gastornis parisiensis, from Eocene strata near Paris; also casts 

 of two leg-bones of another equally large bird, allied to the 

 above, discovered in the Eocene strata near Croydon, viz. 

 Gastornis Klaasseni. A restoration of the French bird's skeleton 

 is shown in Fig. 83. The genus must have been as large 

 as an ostrich, but more robust, with some signs of affinity with 

 geese, as well as to ratite birds such as the ostrich. 



Many other orders of birds are more or less represented by 

 fossil remains from Tertiary strata, but in most cases not so 

 perfectly as to warrant description here. For instance, the 

 Pliocene strata of the Sivalik hills have yielded bones of 



