86 collector's manual 



hair was obtained. To avoid the possibility of the record becom- 

 ing separated from the specimens, it is advisable to number the 

 lots with waterproof ink or black pencil, and to duplicate the 

 key to these numbers in a catalog. 



FOSSIL VERTEBRATES 



Successful fossil hunting requires persistence, concentration, 

 ingenuity, and keen powers of observation. Each specimen is a 

 problem in itself, and each collector will have his own way of 

 working out its details. Whether it be a skull, a few bones, or 

 a complete skeleton, the aim should be to remove the specimen 

 from its resting place in the field to the work table in the 

 laboratory with the least possible injury. An experienced collector 

 may spend hours or even days in taking up a valuable specimen 

 that would be ruined by haste. Months of laboratory work may 

 be required to piece together shattered fragments where the 

 work of removal is done carelessly. 



Vertebrate fossils are most common in the finer-grained, sedi- 

 mentary or stratified rocks that have been deposited by wind 

 and water. Limestones, calcareous shales, and cla3 r s are often 

 f ossilif erous ; coarse sandstones and conglomerates seldom so. 

 Yet it may be found that rocks which ought to contain fossils 

 are barren, while coarse conglomerates may yield teeth and bones. 

 The possibilities of each area must be discovered by careful 

 scrutiny. 



Fossils may appear unexpectedly in drill cores from hundreds 

 of feet below the surface, in dredging and hydraulic operations, 

 road work, quarries, mining, tunneling, gravel pits, wells, railway 



