Lull — Development of Vertebrate Paleontology. 201 



Journal for the year 1836 (29, 307-340) that Hitchcock 

 first called attention to the footmarks, although they had 

 been known and discussed popularly for a number of 

 years previous. James Deane, of Greenfield, was per- 

 haps the first to appreciate the scientific interest of these 

 phenomena, but deeming his own qualifications insuffi- 

 cient properly to describe them, he brought them to the 

 attention of Hitchcock, and the interest of the latter 

 never waned until his death in 1864. Hitchcock wrote 

 paper after paper, publishing many of them in the Jour- 

 nal, again in his Final Report on the Geology of Massa- 

 chusetts (1841), and later in quarto works, one in the 

 Memoirs of the American Academy of Arts and Sciences 

 and the two others under the authority of the Common- 

 wealth, the Ichnology in 1858, and the Supplement in 

 1865, the last being a posthumous work edited by his son, 

 Charles H. Hitchcock. 



Hitchcock's conception of the track-makers was more 

 or less imperfect because of the fact that for a long time 

 but a few fragmentary osseous remains were known, 

 either directly or indirectly associated with the tracks, 

 while on the other hand the bird-like character of many 

 of the latter and the discovery of huge flightless birds 

 elsewhere on the globe suggested a very close analogy if 

 not a direct relationship. Hence "bird tracks" they 

 were straightway called, a designation which it has been 

 difficult to remove, even though in 1843 Owen called atten- 

 tion to the need of caution in assuming the existence of 

 so highly organized birds at so early a period, especially 

 when large reptiles were known which might readily 

 form very similar tracks. The footprints are now 

 believed to be very largely of dinosaurian origin, and 

 dinosaurs whose feet corresponded in every detail with 

 the footprints have actually come to light within the same 

 geologic and geographic limitations. This of course 

 refers to the bipedal, functionally three-toed tracks. Of 

 the makers of certain of the obscurer of the quadrupedal 

 trails we are as much in the dark to-day as were the 

 first discoverers of a century ago, so far as demonstrable 

 proof is concerned. We assume, however, that they were 

 the tracks of amphibia and reptiles, beyond which we may 

 not go with certainty. 



Agassiz, writing in 1865 (Geological Sketches), says: 



