Vol. 6] Miller: Condor-like Vultures of Rancho La Brea. 



5 



account of the quick maceration which would set free the parts 

 of the skeleton. When covered with the thick, oily asphalt, there 

 is no drying of the carcass, hut the soft parts, under the action 

 of putrifactive bacteria, simply break down in their own proto- 

 plasmic fluids. Such conditions favor the rapid settling of the 

 entire skeleton into the matrix. 



The close proximity of the entrapped condor to the body 

 of its prey was probably not infrequently influential in its more 

 perfect preservation. Shielded by the tabular bones of the large 

 mammal the more fragile bones of the bird were often saved 

 from being fractured by the victim next blundering into the pool. 



The firm texture of bird bone, its high degree of pneu- 

 matiacity, permitting the rapid penetration of the larger cavities 

 by the asphalt, the large size and relative robustness of the con- 

 dors, all served as factors conducive to the preservation of the 

 remains of these birds. Considering the general conspiracy of 

 favorable conditions, we may look upon the condor material from 

 the asphalt as representing the Pleistocene condor fauna of this 

 region with a remarkable degree of accuracy. 



DESCRIPTION. 



The part most commonly preserved among the birds is the 

 very dense and powerful tarso-metarsus. Of this segment there 

 are at least twenty-five nearly perfect specimens and a number 

 of fragments. The amount of Recent material for comparison is 

 limited to one specimen each of Gymnogyps and Sarcorhamphus. 



This dearth of comparative material is especially deplorable 

 in view of the large size of the species, which would naturally 

 be expected to follow the tendency of large mammals to vary to 

 a marked degree. The large series of fossil specimens however 

 supplies in a measure this lack of Recent material. 



A careful study of the tarsus of Sarcorhamplms as represented 

 by a small specimen from the Museo de La Plata, and close 

 attention to an account of the large specimen in the Museum 

 of Princeton University by Dr. W. J. Sinclair, show the osteo- 

 logical differences between the North and the South American 

 condors to be inconspicuous so far as the tarsus is concerned. 



