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, which provide the primary evidence for the substrate revolution. The relative ordering of these objects (10[1])are considered when (10[1])invoking the law of faunal succession. Stratigraphic correlation may be performed using easily (10[1])identifiable (10[1])examples of these objects with short temporal range (-5[1])and wide geographic distribution. (10[1])Lagerstätten (-5[1])of these objects include the Burgess Shale and La Brea Tar Pits. (-5[1])For (10[1])10 points, (10[1])graptolites and brachiopods (10[1])are examples of the “index” type of what preserved (10[1])remains of past organisms? ■END■ (10[3])