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 and relative dating. Fossils are important for working out the relative ages of sedimentary rocks. Throughout the history of life, different organisms have appeared, flourished and become extinct. Many of these organisms have left their remains as fossils in sedimentary rocks.