EXTINCT ANIMALS 



peculiar that they are considered as a distinct 

 " class," and the reptiles which come nearest to 

 them in structure are the Dinosaurs, especially 

 those Dinosaurs (like Iguanodon) which walked 

 on their hind-legs and had only three toes to 

 the foot. Fossil remains of birds are not 

 abundant — but a few very interesting birds 

 have been found in the Lower Eocene and in 

 the Cretaceous rocks (see list of strata, p. 60), 

 and one more remarkable than any other in the 

 Lithographic slates of Jurassic age. Modern 

 birds have all got feathers and beaks, and, with 

 one or two rare exceptions, the quill feathers 

 are set on the fore-arm and hand so as to form 

 the wing. No living bird has teeth, but fossil 

 birds are known with well developed teeth Uke 

 those of reptiles. In Fig. 173 is shown the draw- 

 ing of the skeleton of an extinct bird, which 

 had a full set of teeth. The most remarkable 

 extinct bird as yet discovered is that shown 

 in Fig. 174. Two specimens of it have been 

 obtained from the Lithographic slates of 

 Solenhofen in Bavaria. The first one found is 

 preserved in the Natural History Museum ; the 

 second and more perfect is in Berlin. This 

 bird — called Archaeopteryx — Avas of the size of 



2?,6 



