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 (10[1])the primary evidence for the substrate revolution. The relative ordering of these objects are considered when invoking the law of faunal succession. Stratigraphic (-5[1])correlation (10[1])may be performed using easily identifiable examples of these (10[1])objects (10[1])with short temporal range and wide geographic (10[1])distribution. Lagerstätten of these objects (10[1])include the Burgess Shale and La Brea Tar (10[1])Pits. For 10 points, graptolites and brachiopods are examples of the “index” type of what preserved remains (10[2])of past (10[1])organisms? ■END■ (10[1])