Units of Measurement Conversion between metric and English units. 1 meter (m) = 39.4 inches = 1.09 yards; 1 yard = 0.92 m 1 centimeter (cm) = 0.39 inches; 1 inch = 2.54 cm 1 millimeter (mm) = 0.039 inch = 39/1,000 inch; 1 inch = 25.4 mm 1 micrometer or micron (um) = 0.000039 inch = 39/1,000,000 inch; 1/1000 inch = 25.4 um
The most important characteristics to consider when identifying Index Fossils: ABUNDANCE: To best allow paleontologists to correlate rocks with other rocks found at locations far apart, it's important that the index fossil be very widely distributed across a vast geographical region.
Fossils do not always represent a part of the organism. Trace fossils record the activities of organisms. Tracks, burrows, eggshells, nests, tooth marks, gastroliths (gizzard stones), and coprolites (fossil feces) are examples of trace fossils or ichnofossils. Trace fossils represent activities that occurred while the animal was alive. Thus, trace fossils can provide clues to diet and behavior. Ichnology (ichn trace or track, -ology the science of) is the study of trace fossils.