e were no match for the larger predators. The fossilized remains of trilobites are useful because they help scientists developrelative time scales for the ancient marine environment. Because trilobites evolved quicklyand were widely distributed, comparing the trilobite fossils found in rock layers in differentregions of the earth can indicate which rock layer is older than the other. Trilobite fossilsare particularly helpful in developing time scales for the early Paleozoic era. Trilobiteswere highly successful bottom dwelling sea organisms with over 10,000 species. Theythrived for 300 million years as the most abundant and successful ocean animal throughthe Cambrian period until they bit the cosmic dust in the Permian era....
