PORT GIBSON — Friday, commercial fishermen Caroline Curtis and Arthur Bell Jr. made an unusual catch in the Big Black River — but it didn’t have fins, scales, tentacles or any sharp teeth.

Last week, the two were fishing about “three curves” north of the point where the Big Black joins the Mississippi on the Big Black at the Warren-Claiborne line. Their net had snagged. “We kept pulling and pulling,” Curtis said. “I thought we had snagged a log or something.”

When they finally freed and raised their net, they discovered an unusual-looking animal skull in addition to a few fish. “I’ve been a commercial fisherman for 45 years,” Curtis said, “and I’ve never caught anything like this.”

The skull measured nearly 40 inches across the tips of its horns, weighed about 55 pounds and was worn smooth from the flowing river. Its broad, flat forehead made them study it more closely.

“Somebody said it was a cow skull,” Curtis said, but she wasn’t convinced. Bell called the Mississippi Museum of Natural Science in Jackson.

“It’s definitely a bison,” said paleontology curator George Phillips who dispatched another state scientist to Port Gibson to inspect the find. But the skull is no ordinary bison. The skull is a Bison Antiqus or ancient bison said Phillips, dating some 25,000 years to the Pleistocene era or what’s commonly known as the Ice Age.

The animal was the most common large plant-eating mammal in North America of the era. Although the antique bison became extinct about 10,000 years ago, it is a direct ancestor of the living North American bison. However, the ancient bison was taller, had larger bones and horns, and was larger overall than the bison of today.

“It’s definitely a really neat find,” Phillips said. Although similar specimens have been recovered in Mississippi, it is unusual to find a complete skull relatively intact he said. One of two state paleontologists in Mississippi, Phillips said that it is not unusual to find even older bones dating back 70,000 years.

By coincidence, Curtis and Bell were seeking buffalo — but the fish, not the mammal, and buffalo is the common nickname for American bison, although scientists say a buffalo is a different animal, native only to Africa and Asia. Curtis’ boat also bears the name “Buffalo Lady.”

“I’ve caught a lot of big fish,” but never anything like the skull, she said. “I never dreamed I’d catch this kind of buffalo.”

Curtis said she suspects that she snagged the skull because her weighted nets are designed to sink to the bottom of the river to catch fish.

Curtis said the skull is by far the most unusual thing she’s ever caught. She said she has caught dozens of large fish, including a 65-pound catfish and a 130-pound loggerhead turtle. Normally, Curtis said she launches at the Claiborne County Port, but recent low water levels have made it unsafe to launch there. Instead, she has been using a launch at a nearby deer camp to get her 16-foot boat in the water.

Bell, who is Curtis’ grandson, said they haven’t yet decided if they’re going to keep the skull or give it to the museum. Located in LeFleur’s Bluff State Park in Jackson, Phillips said the museum currently has exhibits featuring similar finds.