Pleistocene Fossils Found in Southwestern Georgia and Southeastern Alabama

Geologists refer to the upper coastal plain of Alabama and southwestern Georgia as the “southern hilly Gulf Coastal Plain.”  The terrain alternates between irregular flat plains and gently rolling hills.  Many creeks and rivers erode through sediments of differing ages, exposing fossiliferous deposits that date from the Cretaceous to the Pleistocene.  During the Pleistocene a mosaic of deep forest, open woodlands, savannah, prairie, and wetlands covered this region.  Pollen from composite species (sunflowers, daisies, etc.) and pine increased during arid stadials while warmer wetter interstadials saw an increase in broad-leafed tree abundance.  Most of the plant species that occurred here then are still extant but the extinct Critchfield’s spruce; a temperate species that grew alongside oaks, walnut, and elm; was a component of this primeval wilderness.

Fossil hunters have collected mastodon fossils from Hannahatchee Creek in Stewart County, Georgia; Bogue Chitto Creek in Dallas County, Alabama; and the Warrior River in Alabama. (See:http://www.archeologyink.com/Ice%20Age.htm) Hannahatchee Creek is better known for Cretaceous fossils.  Most of the Cretaceous fossils found here are of marine species but teeth of nodosaurs, hadrosaurs, and tyrannosaurs have been collected from the stream bed.  A mastodon tooth was recovered about 1/2 mile west of Union, Georgia along Hannahatchee Creek, and a leg fragment of a mastodon was picked up upstream near Omaha.  I looked at a satellite image of this creek.  The owners of the land here allow a narrow strip of natural creek bottomland to grow, but most of the area appears to be pine plantation.  This is unfortunate because pine tree farms support very little wildlife.  During the Pleistocene the land bisected by Hannahatchee Creek could have consisted of cypress swamp, bottomland hardwoods, beaver meadows, grassy marshes, and/or canebreaks.  All of these environments would’ve made excellent habitat for semi-aquatic mastodons.

Hannahatchee Creek erodes through strata of different ages from the Cretaceous to the Pleistocene.

Mastodon Tooth

A mastodon tooth was found in Hannahatchee Creek.

Other Pleistocene remains have been recovered from at least a dozen small creeks that flow through the upper coastal plain of Alabama and Mississippi.  They include mammoth, horse, tapir, bison, white-tailed deer, long-nosed peccary, flat-headed peccary, giant beaver (Casteroides sp.), pampathere (a 300 lb armadillo), Jefferson’s ground sloth, Harlan’s ground sloth, gray fox, coyote, Florida spectacled bear (Tremarctos floridanus), giant short-faced bear (Arctodus simus), black bear, margay cat (Leopardus wiedii), and indigo snake.  The margay cat currently ranges throughout tropical forests in Central and South America, but it formerly lived in southeastern North America.  Fossil remains of the margay have been found at 2 sites in Georgia, 12 in Florida, and 3 in Mississippi and Alabama.  The latter 3 are not listed in the Paleobiology database, and I was unaware of these specimens when I wrote a blog post about this species (See: https://markgelbart.wordpress.com/2013/05/09/the-mystery-cat-of-pleistocene-georgia/).

Margay hanging from tree.

Margay fossil remains found in Alabama and Mississippi have not been posted on the paleobiology data base or faunmap.

Horse teeth dating to the Pleistocene are particularly abundant in these small creeks.  This suggests the presence of extensive grasslands in the Black Belt Prairie region that stretches across Mississippi and Alabama.  Disjunct areas of Black Belt Prairie are also found in south central Georgia.  Herds of horses attracted large predators such as dire wolf, saber-tooth, scimitar-tooth, giant lion (Panthera atrox), and jaguar.  There is some scant evidence of dire wolf in this region, but it is undocumented.  Fossil remains of the other 4 large carnivores have been found in adjacent regions, so it’s very likely they occurred on the upper coastal plain.  The first Panthera atrox fossil was found in northern Mississippi, and giant lions are part of Florida’s and South Carolina’s fossil record.  Jaguars fossil remains have been found in Georgia, Florida, and South Carolina. Saber-tooth remains have been excavated from northern Alabama, Florida, Tennessee, and South Carolina.  Scimitar-tooth bones were discovered in Tennessee and Florida.

George Phillips wrote an excellent Masters Thesis about Pleistocene fossils from this region, focusing on the non-mammalian species.  He did mention in his thesis that he would write in the future about ocelot (Leopardus pardalis) and dire wolf (Canis dirus) remains found here.  His thesis was written in 2006, yet I can find nothing on the internet about ocelot and dire wolf remains found from Alabama.  I assume this data is still unpublished.  However, an amateur fossil collector informed me that he collected a dire wolf tooth (along with mammoth, bison, and horse bones) from the Flint River in Georgia.  Dire wolves undoubtedly were a major predator of the upper coastal plain during the late Pleistocene.  As far as I know, no scientist has ever prospected the Flint River for fossils.

George Phillips thoroughly studied fish and turtle remains eroded from streamside fossil deposits.  The fish remains belonged to the same species that swim in Alabama creeks today–gar, bowfin, suckerfish, catfish, freshwater drum, and sunfish.  But some of the turtle remains belonged to species that are extinct or no longer live in the region.  That will be the subject of my next blog entry.

References:

Kurten, Bjorn and John Kaye

“Late Quaternary Carnivora from Black Belt, Mississippi”
Boreas 1982

Phillips, Georgia

“Paleofaunistics of Non-mammalian Vertebrats from the Late Pleistocene of the Mississippi-Alabama Black Belt Prairie”

North Carolina State Masters Thesis 2006

Shwimmer, David

“First Mastodont Remains from the Chattahoochee River Valley in Western Georgia, with implications for the Age of Adjacent Stream Terraces”

Georgia Journal of Science 1991

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