Paleontology and geology
During the Quaternary, sea level fluctuated, as glaciers grew and melted in the northern part of North America. Although these glaciers never extended to Alabama, they impacted both the climate and biodiversity of the state. Forests of northern conifers such as spruce covered northern Alabama, while mixed, drought-tolerant forests and grasslands dominated the south. Fossils of huge animals such as mammoths, mastodons, and giant ground sloths are routinely discovered in streams and sinkholes across the state, testifying that these huge beasts called Alabama home during this time.
This map indicates the presence of Quaternary rocks across a broad area of the southern part of the state.