The Cambrian in North Dakota, US

Paleontology and geology

Shallow, warm seas covered much of North Dakota during the Cambrian Period. Sands, muds, and carbonates were deposited in these seas. The most abundant fossils in these rocks are those of conodonts, but there are also remains of brachiopods and trilobites. Cambrian rocks are not exposed at the surface, but information about them comes from drill cores.