Paleontology and geologyDuring the Early Jurassic, North Dakota was a subtropical, forested, low-elevation plain. Later in the Jurassic, a shallow sea flooded the state, resulting in the deposition of evaporites, red beds, limestones, and shales. Fossils of gastropods, bivalves, echinoderms, and foraminifera are found in these Jurassic rocks. |