212 EXTINCT MONSTERS 



already alluded (see p. 126) to Professor Huxley's theory that 

 birds are descended from Dinosaurs; but though there is much 

 to be said in favour of the idea, we prefer, for our part, to wait 

 and see what evidence may yet turn up on this subject, and, like 

 the Irishman, to "prophesy after the event," i.e. when further 

 discoveries have been made. Sir E. Owen never favoured the 

 theory, and, for all palaeontologists can tell, it may just as well 

 be that both birds and pterodactyls (flying reptiles) are descended 

 from a common stock ; the one line choosing to fly by means of 

 a thin membrane attached chiefly to a single long finger, while 

 the others thought they could do quite as well in fact better 

 by growing feathers on their arms and fingers. All great 

 problems in Nature are solved slowly, by the patient accumulation 

 of evidence ; and the one above alluded to is no exception to the 

 rule. 



Palaeontologists are not without evidence bearing on this 

 subject ; so perhaps we cannot do better than state briefly what 

 that evidence is, in order to show how near, or how far, we are 

 from a final answer to our question. Though no one can yet 

 say what the very first bird-type was like, we can, at all events, 

 describe the oldest known fossil bird. This is the famous 

 Archseopteryx. 1 



Time was and that within the memory of living geologists 

 when no fossil birds were known in rocks older than the Tertiary 

 deposits ; but the discovery of Archasopteryx has changed all that, 

 and we now trace back the bird line to the middle of the great 

 Secondary or Mesozoic Era. This bird was found in the 

 Solenhofen limestone of Bavaria, which is supposed to represent 

 the lower part of our English Kimmeridge clay. First, only the 

 impression of a single feather was known, to which the late 

 1 Greek Archios, ancient ; pterux, wing. 



