About 112 million years ago, a long-necked sauropod dinosaur traversed some intertidal flats near what is now Glen Rose, Texas. Coming after it — perhaps hours or days later, or perhaps hot on its tail in a dinosaur chase scene — a meat-eating theropod followed, overlaying some of the sauropod's footprints with its own.
This snippet of the Cretaceous ended up frozen in rock, and paleontologists discovered the prints as early as 1917. But an excavation in 1940 led to a third of the trackway vanishing. Now, researchers have reconstructed the entire trackway, all 148 feet (45 meters) of it, using old photography and new technology.
"It's great to get so many stride lengths, so many depths and impressions," said study researcher Peter Falkingham, a research fellow at Royal Veterinary College in London. "There's all this data you can get from an animal moving over quite a long distance."
The dinosaur footprints come from a larger site full of tracks called the Paluxy River Trackway. The sauropod and theropod prints comprise one of the most famous sequences from the site. In 1940, fossil collector Roland T. Bird excavated the tracks. A third of the sequence went to the American Museum of Natural History in New York; another third went to the Texas Memorial Museum, and a final third was lost.
"It's entirely possible that there are some parts of it in a garage somewhere," Falkingham told Live Science. Portions of the fossil could have been sent to other institutions and lost, or perhaps left at the site and eroded away by the river, he said.
Written By: Stephanie Pappas
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