Where bison roamed: Paleontological dig shows a different Georgia

Produced by University Communications

 

I magine a Georgia—60,000 years ago—where the coastal city of Brunswick was 70 miles from the ocean and most of the state was a great, grassy plain where the bison and mammoths roamed.

Paleontology is a true liberal arts science because of all the passion of discovery that goes along with the liberal arts.
– Dr. Al Mead
In an era when most people think paleo is a diet, a small public liberal arts school in Central Georgia is leading the way to unearthing this past.

In doing so, it reminds the world just how hip and modern real paleontology can be.

“Some people say paleontology is a dying profession and, at big research universities, that’s probably true. Many have eliminated their paleontology departments,” said Dr. Al Mead, a biology professor at Georgia College & State University in Milledgeville, Georgia.

“But in this environment,” he said, “it can thrive. Paleontology is a true liberal arts science because of all the passion of discovery that goes along with the liberal arts.”

Mead is a paleomammalogist who studies ecosystems of the past.

Dr. Al Mead at the dig site in Brunswick, Georgia.
Dr. Al Mead at the dig site in Brunswick, Georgia.

In the last 20 years, he and about 40 Georgia College students have dug and backfilled muddy trenches in the swampy marshes of Southeast Georgia. Since excavating a near-complete bison skull in 2002, they’ve uncovered thousands of prehistoric bones, bone fragments, shells and teeth.

In recent years, scientists from other universities have joined the Georgia College team. They come together for a collaboration of minds, each sharing their expertise to help paint a better picture of what happened long ago at the Pleistocene-aged site.

A near-complete bison skull.
A near-complete bison skull.
Their discovery points to a past that teaches us about the future, about climate change and about survival of the human race.

“One of the primary lessons here is we’re looking at the effects of climate change,” Mead said. “There is a use for paleontology. If we understand history, then we can make a valid prediction about what happens next.”

The dig site—the only excavation of its kind in Georgia—was discovered by twin brothers in 2001. Joshua and Kelly Clark were in high school at the time but later got undergraduate and masters’ degrees at Georgia College in 2006 and ’09.

Sloshing through the creek on their family property, looking for salamanders to feed their pet turtle, they came across an enormous black bone sticking out of the muck.

Unsure of what it was, they gave the bone to their sister who was studying at the University of Georgia (UGA). Professors there turned to Mead, the area’s sole expert on fossilized mammal bones.

He took one look and knew instantly: It was the jawbone of a prehistoric bison—an enormous creature weighing about 3,000 pounds with a horn span of 7 feet.

There is a use for paleontology. If we understand history, then we can make a valid prediction about what happens next.
– Dr. Al Mead
Mead recalled reading about a similar find in the same area along the Brunswick Canal, dug in the 1830s. The dredging unearthed a large tooth, catching the attention of world-renowned geologist Sir Charles Lyell. He brought the fossil back to England for study. It was the remains of a Columbian mammoth—then long extinct.

Finding mammoth bones only miles from the Atlantic “was just unheard of,” Mead said. The giant, long-tusked elephant, like bison, prefer grazing areas like the American Great Plains.

After the 1800s, talk of bison and mammoth bones in Georgia faded almost into legend—until the Clark brothers took their fateful walk.

The jawbone they discovered proved giant prehistoric mammals did once inhabit Georgia. Back then, the environment looked much different than the seaside marshes and thick, Spanish-mossed forests we see today.

“Georgia would’ve been similar to the great prairies, not this jungle of trees we’re standing in now,” Mead said. “Paleontology gives us an indication of what the climate was like back then, what the vegetation was like and what kind of organisms lived here.”

Graduate biology student Todd Bennett.
Graduate biology student Todd Bennett.
“Today, we’re in a period where carbon dioxide levels in the atmosphere are increasing rapidly. 2020 was the hottest year ever recorded, since recording began,” he said. “What’s within the realm of possibility? Can it get much warmer? Has it been this warm before?”

Questions like these can be solved by examining riddles of the past.

Mead relies on scientists from other universities, like Dr. Alex Cherkinsky, a carbon-dating expert from UGA; Dr. David Patterson, an isotope paleontologist from the University of North Georgia (UNG); Chris Seminack, a sedimentologist from UNG’s Gainesville campus; and Russell Cutts, an anthropologist at Oxford College of Emory University in Atlanta. Other collaborators come from Kennesaw State University in Georgia, Temple University in Philadelphia and Utah State University.

The core team is a labyrinth of Georgia College connections—such as Mead’s wife, Heidi, the university’s fossil technician who teaches students to prep, catalogue and store specimens.

Former students, like the Clark brothers, still contribute. Josh is an instructor and Kelly a lab coordinator at Brunswick’s College of Coastal Georgia. Josh co-authored a paper on snakes at the site, and Kelly is working with Mead to describe birds from that time.

Mead’s current graduate student, Todd Bennett, is researching rodent taphonomy—how biological material fossilizes after death—and looking for evidence of rodent bones from owl pellets to determine the ecological landscape.

Science these days is not what science used to be. You have to bring in people who are relevant to your questions and experts in things that you are not. You have to able to work with them, listen to them. It really propels the project forward.
– Dr. David Patterson
Bennett studied undergraduate biology at UNG under Patterson, who worked the site as a Georgia College undergraduate and graduate student, ’07 and ’09. Through carbon and oxygen readings in teeth, he determines what plants prehistoric animals were eating and what the environment looked like.

“Science these days is not what science used to be,” Patterson said, “where you can be an expert in every subject. You have to bring in people who are relevant to your questions and experts in things that you are not. You have to able to work with them, listen to them. It really propels the project forward.”

(Left to right) Todd Bennett, Dr. Al Mead, Dr. David Patterson and Heidi Mead.
(Left to right) Todd Bennett, Dr. Al Mead, Dr. David Patterson and Heidi Mead.

The dig site is a boggy acre named Clark Quarry after the twins. For years, only Mead and Georgia College students dug there. Some summers, they waded chest deep through tick-infested, cypress wetlands to get to the site—hidden off a residential road in Brunswick.

Teams sweat in the heat, swatting at swarms of mosquitoes, as they pickaxe and shovel through dirt and hardened clay to get to the sandy layer, 6 feet down, where fossils are found.

Excavated mounds of dirt are thrown onto a screen for spraying. As soil washes away, the group identifies tiny pieces—like raptor claws, hip bones of frogs, mice teeth, lizard jaws and shells.

Mead holds the jaw of a juvenile mammoth.
Mead holds the jaw of a juvenile mammoth.
The biggest fossil they’ve found is the enormous shin bone of a mammoth.

Over the years, they’ve discovered teeth, jaws, elbows, shoulder blades, ribs, feet and horns of bison; bones of giant rodents the size of dogs; and shells of now-extinct large turtles.

This summer, for the first time, they found the partial skull of a juvenile mammoth.

It’s hard work. But recruiting students is easy.

Patterson recalls his digs as a student—emerging at day’s end exhausted, caked in mud and excited. He considered going pre-med and becoming a doctor. But getting dirty and finding bones in the ground changed his mind.

“Even as a kid or college student,” Patterson said, “you think it’s really not possible to be a paleontologist, like it’s not a real job. It’s something you see in the movies.”

“But it was really interesting to me,” he said. “It allows you to look back into this world that’s very different than the one we live in now.”

Students and scientists at the dig site this summer.
Students and scientists at the dig site this summer.

Bennett is interested in evolutionary biology. He hopes to find bones of predators. So far, the only evidence of their presence 60,000 years ago are the damaged remains of bison and mammoths—suggesting they were attacked and killed by carnivores.

At least five bison found at the site—adults and juveniles—don’t appear to have died all at once in a natural catastrophe.

There are bite marks all over these bones, but we don’t have any fossils of the carnivores...
– Todd Bennett
The climate was in flux, very much like today, forcing mammals to gather around shrinking water holes where vegetation still existed. That made them easy prey for big sabertoothed cats, large cave bears and dire wolves, who lived at the time.

“There are bite marks all over these bones, but we don’t have any fossils of the carnivores, which is interesting,” Bennett said. “Why are we missing that group? We have snakes, birds, turtles, frogs, lizards, bison, mammoths, deer—but no carnivores. They must’ve eaten and died somewhere else.”

The team thinks bison, however, died in this one location at separate times. If they’d died together in a flood, bones from each mammal would be in one place, Bennett said, not scattered as if pulled apart and dragged by predators.

Clues supporting this hypothesis include a broken bison horn. It was already skeletonized before being buried.

The humerus bone of a bison.
The humerus bone of a bison.
Bones have puncture marks and parallel scratches, suggesting they were gnawed and trampled upon. Often, one side of a bone is cracked and more aged, as if left in the sun, while the other surface is soft and smooth. This indicates bones may have lay on the ground for years before burial.

“What we envision,” Mead said, “is a gradual accumulation of bones on the floodplains, and then floodwaters came and pushed all that sand. It’s like putting icing on a cake—there’s a layer of sand all across the floodplain.”

Finding bison and mammoths in Georgia always seemed a bit preposterous, which makes solving this puzzle even more satisfying.

It took all the right elements in place for Mead to find what has become the greatest discovery of his career.

He now lives to see the thrill of discovery in his students.

What I look forward to seeing most is the students’ eyes lighting up when they find that jaw or that tooth and realize they’re the first human to ever see it. It sparks the passion of discovery.
– Dr. Al Mead