Paleontology and geologyThere are no surface rocks of Ordovician age in Nebraska. However, drill cores reveal that the sea invaded the state in the middle Ordovician, and its shallow waters were populated by reefs with shelly animals and marine microorganisms. Few fossils are available from the drill cores, but fossils would be similar to Ordovician reef fossils from Missouri and might include brachiopods, bryozoans, gastropods, trilobites, and corals. |