Lull — Development of Vertebrate Paleontology. 219 



bore ; while the laws of f aunal coloration have permitted 

 the coloring of the restoration in a way which if not the 

 actual hue of life is a very reasonable possibility. 



Thus the American paleontologists have blazed a trail 

 which has been followed to good effect by certain of their 

 Old World colleagues. 



With such means and methods and such material avail- 

 able, it is again not surprising that American paleontology 

 has furnished more and more of the evidences of evolu- 

 tion, and disclosed to the eyes of scientists animal rela- 

 tionships which were undreamed of by the systematist 

 whose research dealt only with the existing. It has also 

 explained some vexatious problems of animal distribution 

 and of extinction, and has connected up cause and effect 

 in the great evolutionary movements which are recorded. 



The results of systematic research have added hosts of 

 new genera and species and of families, but of orders 

 there are relatively few. Nevertheless a number, 

 especially among reptiles and mammals, have come to 

 light as the fruits of American discovery. But aside 

 from the dry cataloguing of such groups, the American 

 systematists have worked out some very remarkable phy- 

 logenies and have thus clarified our vision of animal 

 relationships in a way which the recent zoologist could 

 never have done. In this connection, the Permian ver- 

 tebrates, which have been collected and studied with 

 amazing success, principally by Williston and Case, 

 should be mentioned, although the work is yet incom- 

 plete. Some of these forms are amphibian, others rep- 

 tilian, yet others of such character as to link the two 

 classes as transitional forms. Of the Mesozoic reptiles, 

 a very remarkable assemblage has come to light, in a 

 degree of perfection unknown elsewhere. These are dino- 

 saurs, of which several phyla are now known; carnivores 

 both great and small, some of the latter being actually 

 toothless ; Sauropoda, whose perfection and dimensions 

 are incomparable except for those found in East Africa ; 

 and predenfates, armored, unarmored, and horned, the 

 last exclusively American. The unarmored trachodonts 

 are now known in their entirety, for not only has our 

 West produced articulated skeletons but mummified car- 

 casses whose skin and other portions of their soft 

 anatomy are represented, and which are thus far without 

 a parallel elsewhere in the world. Other reptilian 

 groups are well known, notably the Triassic ichthyosaurs, 



