Paleontology and geology
Although not shown on this map, Devonian-aged rocks are part of the Black Warrior Basin in the extreme northeast corner of the state. Dark-colored marine rocks in this area indicate that a sea, with regions of deep, oxygen-poor water, covered this part of Mississippi in the Late Devonian. Few organisms could have tolerated these conditions. As a result, fossils from these rocks are limited primarily to plant fragments and the remains of animals that swam above the deeper, oxygen-starved waters.