The unreliability of the first and last observed instances of these objects is explained through the Signor–Lipps effect. Ichnologists (“ick-NOL-uh-jists”) study so-called “trace” examples of these objects, (10[4])which (10[1])provide (10[1])the primary evidence for the (10[1])substrate revolution. (10[1])The relative (10[1])ordering of these objects (10[2])are (10[1])considered (10[1]-5[1])when (10[1])invoking the law of faunal (10[2])succession. (10[6]-5[1])Stratigraphic (10[3]-5[2])correlation (10[5])may (10[1])be performed using easily (10[2])identifiable (10[2]-5[1])examples (10[2])of these (10[2])objects (10[5]-5[3])with short (10[1])temporal (-5[1])range (10[1]-5[2])and wide (10[1])geographic (10[5]-5[3])distribution. (10[7])Lagerstätten (10[1]-5[1])of these (10[1])objects (10[3])include the Burgess Shale and La (10[1])Brea (-5[1])Tar (10[2])Pits. (10[3]-5[1])For (10[1])10 points, (10[2])graptolites (10[3])and brachiopods (10[1])are examples (10[1])of the (10[1])“index” (10[1])type (10[1])of what (10[1])preserved (10[3])remains (10[4])of past (10[1])organisms? (10[4])■END■ (10[18])