This story is part 10 of the AL.com series “Ancient Alabama,” examining the natural forces that made Alabama what it is over the past 500 million years, and how those forces still shape the state today. It’s ironic that to find the fossils of some of the largest sea creatures ever to roam ancient Alabama, you have to go to a place that looks like a desert. The weathered chalk gullies at Harrell Station Paleontological Site in Dallas County could almost be mistaken for Saharan sand dunes, or at least a large Gulf of Mexico beach without the actual Gulf. But these gullies are made of Mooreville chalk, like so much of the bedrock in Alabama’s Black Belt. Wind and water have carried away about 82 million years of topsoil and rock, exposing the late Cretaceous sediments underneath.

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Ancient Alabama – Mosasaurs
Harrell Station Paleontological Site in Dallas County, Ala.

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Dennis Pillion | [email protected]
Ancient Alabama – Mosasaurs
Adiel Klompmaker shows mosasaur teeth and jawbones at the Alabama Natural History Museum in Tuscaloosa, Ala.

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Dennis Pillion | [email protected]
Ancient Alabama – Mosasaurs
The fossil skull and jaws of “Sweetie,” one of the largest mosasaurs ever discovered. Scientists estimate that Sweetie may have been up to 50 feet long. The remains were found in Lowndes County and are about 70 million years old.

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Ancient Alabama – Mosasaurs
Fossil collector Benji Deason shows three mosasaur vertebrae he found at Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Additional mosasaur teeth and jaw bones in the collection at the Alabama Museum of Natural History on the University of Alabama campus in Tuscaloosa.

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Ancient Alabama – Mosasaurs
Fossil fish vertebrae found at Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Adiel Klompmaker wraps and bags a fossilized fish bone at Harrell Station in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Ricky Mims next to the spot where he discovered an 82-million-year-old partial fish skeleton at Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
The back fins and tail of “Artemis,” a juvenile mosasaur found in Greene County that is one of the most complete mosasaur skeletons ever found.

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Ancient Alabama – Mosasaurs
Mosasaur teeth, jawbones and vertebrae on display at the Alabama Natural History Museum in Tuscaloosa, Ala.

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Ancient Alabama – Mosasaurs
Coprolite, or fossilized dung, showing the vertebrae from a fish that a predator had eaten some 82 million years ago.

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Ancient Alabama – Mosasaurs
A fossil mosasaur skull in the collection at the Alabama Natural History Museum in Tuscaloosa, Ala.

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Ancient Alabama – Mosasaurs
Fossil collector Benji Deason shows three mosasaur vertebrae he found at Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Adiel Klompmaker and members of the Alabama Paleontological Society look for additional fragments of a partial fish skeleton discovered by Ricky Mims Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Small rocks on pedestals at the Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
The rear fins and tail of Artemis, a juvenile mosasaur found in Greene County, Ala. in 2002.

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Ancient Alabama – Mosasaurs
The skull of a massive turtle found near the Black Warrior River north of Demopolis, Ala.

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Ancient Alabama – Mosasaurs
AL.com reporter Dennis Pillion at the Alabama Museum of Natural History.

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Ancient Alabama – Mosasaurs
Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
The remains of the mosasaur nicknamed “Bossie” were found along the Tombigbee River in Greene County in 1993.

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Ancient Alabama – Mosasaurs
The remains of “Bossie,” a mosasaur found in Greene County, Ala. at the Alabama Museum of Natural History.

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Ancient Alabama – Mosasaurs
Adiel Klompmaker at the Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Adiel Klompmaker looks for fossils at the Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
The spine and front flippers of Artemis, one of the most complete mosasaur skeletons ever recovered.

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Ancient Alabama – Mosasaurs
Reconstruction of a prehistoric fish on display at the Alabama Natural History Museum in Tuscaloosa, Ala.

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Ancient Alabama – Mosasaurs
An 82 million year old turtle shell at the Alabama Natural History Museum in Tuscaloosa, Ala.

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Ancient Alabama – Mosasaurs
Adiel Klompmaker shows a metatarsal (foot) bone belonging to a hadrosaur with a shark tooth embedded in it. The bone was found in Greene County and is approximately 80 million years old.

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Ancient Alabama – Mosasaurs
Fossil hunter Hayley Nedbalski explores the chalk gullies at the Harrell Station Paleontological Site in Dallas County, Ala.

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Ancient Alabama – Mosasaurs
Size comparison of turtles at the Alabama Museum of Natural History.