MILRY, Alabama --

Lying on the creek bed, dark blue against the pebbled bottom, the shark tooth is unmistakable.

The tooth is small, about an inch and a half long, but the point is still sharp to the touch.

It is probably about 40 million years old.

The tooth was found in a small Choctaw County creek near the town of Milry. It drains into the Tombigbee River. Like many of the creeks in Choctaw, Clarke, Monroe, Hale, Greene, Marengo, and Sumter counties, it is full of shark teeth. At least if you know where to look.

The state’s rich fossil past has been an open secret for more than a century. There are multiple references to expeditions to Alabama to collect fossils, including shark teeth in Choctaw County, in the annual report of the Smithsonian Institution from 1895.

Three hours spent on hands and knees in the creek, which is about 6 feet across and knee deep in the deepest parts, yielded 300 teeth, some small enough to fit on a pinky nail, others close to 2 inches long. Most were found by sifting through the gravel with mesh screens, almost like panning for gold.

In the mix were teeth from tiger sharks, sand tiger sharks, and a number of prehistoric species thought to have gone extinct long ago. Mixed in the group of prehistoric sharks was one known as Galeocerdo alabamensis, so named because most of the fossils of the species were found in this state.

The haul also included teeth from an extinct species of snaggletooth shark, which sported wide, serrated teeth on the top jaw for cutting into prey, and long, pointy needle-like teeth in the bottom jaw for holding onto its victims while eating.

Tiny, exceptionally sharp teeth belonged to an ancient relative of the angel shark, or monk fish, a bizarre species that lies flat against the seafloor, almost like a flounder. Finely toothed pieces that resembled small hair combs were the molars from an extinct species of eagle ray, a kind of stingray. There were also small bits of coral, bleached white with age, and so fragile they crumbled when handled.

Ancient shark teeth 13 Gallery: Ancient shark teeth

The teeth are relics from an ancient and watery past, from a time when most of the southern half of Alabama was underwater. If you study a satellite image of Alabama, you can see a broad band of gray that arcs across the middle of the state.

That band represents an ancient seashore. As the various ice ages came and went over millions of years, sea level rose and fell around the globe. For Alabama, those changes meant sea level changed dramatically, by hundreds of feet at a time.

An underwater cypress forest explored by AL.com in 2012 that lies about 10 miles south of Fort Morgan represents sea level about 50,000 years ago, during the recent ice age, while sand dollars found along the Alabama River near the Claiborne Dam and the sharks teeth in this creek show how much higher the seas were 40 million years ago, during an ancient warm period.

Martin Becker, chair of environmental sciences at William Patterson University in New Jersey, is an expert in fossil shark teeth, and has led several expeditions to collect fossils in Alabama. He identified the teeth found by AL.com.

“It looks like an Eocene locality, that puts it at around 40 mill years old,” Becker said, determining the era the teeth came from by identifying the species they belonged to. Becker published a scientific paper a few years ago about teeth he found farther north, in Greene County. Those teeth, estimated to be 80 million years old, were aged by studying the amount of radioactive material present in them.

“The teeth you found have been tumbled around a good bit, so that makes identification a little more difficult. But we can see a few species there,” Becker said. “What’s happening is the teeth you are collecting, you have a geologic unit the teeth are eroding out of and then being incorporated into the modern river gravel.”

Tiny tiger shark teeth still have their telltale serrations after 40 million years. (Ben Raines/braines@AL.com)

The teeth were indeed mixed in with the small, pea-sized gravel found in the creek. Most of the teeth were found in close proximity to limestone ledges running along the bank.

Jason Gillikin discovered the fossil-rich creek during his time with the Alabama Forestry Commission. He said there are dozens of creeks in the state where it’s possible to find fossils of marine creatures, from nautilus and sea urchins, to shark teeth and sand dollars.

“I usually first look at maps to find out where the limestone deposits are. That starts you off. You are not going to find anything unless there is limestone,” Gillikin said. “You find a lot of that in Choctaw County and Monroe County. You’ll find a lot of old seashells in that. You find that, you’ll find the teeth.”

Some locations have lots of ancient coral, others have just seashells, he said. Some have a mix of various creatures. Around Linden, Gillikin said he finds fossilized sea creatures, such as sea urchins. Near Demopolis, he finds giant oysters.

“We found these teeth where those banks were eroding that limestone. I think it just releases them,” Gillikin said. “In the creek, I look for sediment areas, eddies or places were things have been naturally collecting, like curves. Anywhere you find a concentration of pebbles and debris, that’s where you’ll find fossils and shells and things.”

He said he prefers to collect in the colder months to avoid water moccasins. He typically wears a wetsuit or waders. He runs a plastic scoop with a handle across the bottom to gather pebbles, then pours the rocks into a wide plastic bowl with a mesh bottom.

“I bought those from a commercial food supply place that sells to restaurants. They are screens for washing vegetables. I like those big flat ones because you can spread out what you’ve got and look in it,” Gillikin said. “The curved ones don’t work so well because everything bunches up in the bottom and you can’t see what you’ve got. You want really small holes so the teeth don’t fall through.”

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