The Texas floods washed away debris and dirt. They also uncovered 100-million-year-old dinosaur tracks

The devastating flooding that swept through Texas Hill Country in early July, killing at least 135 people, unearthed a prehistoric discovery in Travis County on Monday, experts say.

A volunteer helping residents clear debris discovered 15 large, three-clawed dinosaur footprints scattered in a crisscross pattern along the Sandy Creek area.

“The tracks that are unambiguously dinosaurs were left by meat-eating dinosaurs similar to Acrocanthosaurus, a roughly 35-foot-long bipedal carnivore,” said Matthew Brown, a paleontologist with the Jackson School Museum of Earth History at the University of Texas at Austin.

The tracks are approximately 110 to 115 million years old and each footprint is roughly 18 to 20 inches long, according to Brown.

Waterways like the Sandy Creek “cut through the Glen Rose Formation limestone, which is the rock layer that bears the tracks and is about 110ish million years old,” Brown said. “And so, that’s how we know how old the dinosaur tracks are, it’s because they’re preserved in rock layers that are that old.”

Brown visited the site of the dinosaur tracks Tuesday to provide recommendations to state and county officials about the active disaster response nearby and has since learned about other recently uncovered sites that may also have dinosaur tracks.

“We’ve been talking with the environmental monitoring company too about sensitive locations that they’ve gotten from the state and what to watch out for … basically, to make sure that they’re not rolling heavy equipment across the trackways,” he said, to prevent damage to the dinosaur tracks. “That’s the sort of the information that we’ve been providing, just trying to identify positively tracks and then sort of set boundaries around them for the cleanup crews to give them some guidance while they’re working in the area.”

Pictures from Texas resident Carl Stover show the tracks are somewhat bigger than his sneakered foot and embedded firmly in the rocky white terrain.

That terrain, combined with swollen rivers and streams in Central Texas, makes the area in the heart of “Flash Flood Alley” prone to flooding.

While most of the damage and deaths brought by the July floods was concentrated in Kerr County, there were 10 deaths in Travis County – which includes the city of Austin and its suburbs – and parts of the area were also inundated by the catastrophic storm.

Travis County Judge Andy Brown said Sandy Creek is typically very dry but rose to 20 feet during the flooding last month.

“That washed away trees. It washed away cars, houses, anything in its path,” Brown said. “So, in this part with the dinosaur tracks … it tore down the trees around them and it also washed away the dirt and gravel that was over the other set of them.”

Stover, who shared video with CNN, panned his camera over the dinosaur tracks by the creek bed.

“This whole area was flooded on the July Fourth flood. I don’t know if you can tell, but there used to be a house right here that got washed away,” he said, his camera lens focused on piles of debris amid clumps of trees. “Another one right down from it. And my other neighbor here, this house is gone also.”

Brown, the county judge, said even as Travis County is in the middle of disaster recovery, the dinosaur tracks are “exciting to see.”

“We have a lot of dinosaur footprints around Texas in different areas,” he added. “Just picturing what used to roam in this area is fascinating exercise.”

Travis County is a little under 200 miles south of Dinosaur Valley State Park, home to a large number of dinosaur tracks imprinted by sauropods and theropods that lived in the area roughly 113 million years ago. It is a hotspot for dinosaur enthusiasts and tourists who typically flock the now-dry Paluxy River to fish, swim and kayak.

Matthew Brown, the paleontologist, said he and his team expect to return to Travis County soon to thoroughly document the tracks with maps and 3D imaging.

Brown said he hopes to learn more about how many creatures are represented by the tracks – and whether they were left by a group or by a single dinosaur roaming Texas Hill Country.

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