Scientists at the University of Alaska Fairbanks have discovered and documented the largest known single dinosaur footprint in Alaska. Located within Denali National Park and Preserve, this stunning site has been named “The Colosseum” by experts.
The size of a football field and a half, the Coliseum is a remarkable collection of rock formations, each preserving a wealth of dinosaur footprints. This site provides comprehensive historical descriptions of various dinosaurs. seed About 70 million years ago, they thrived in what is now known as the Alaska Interior. A detailed description of the researchers’ findings and the Colosseum was published in a recently published paper. historical biology.
“This is more than just a single layer of rock,” says Dustin Stewart, lead author of the paper and a former UAF graduate student who published the paper as part of his master’s thesis. “It’s a timeless sequence. There have been other known track sites in Denali before, but nothing as big as this one.”
At first glance, the site is inconspicuous in the park’s vast landscape, consisting only of a layered rock outcrop about 20 stories high from its base.
“When our colleagues first visited the site, they saw dinosaur tracks at the base of this massive cliff,” said Pat Drakken, lead author of the paper and director of the University of Alaska Northern Museum. Mr Miller said. “Even when we first got out there, we didn’t see much.”
Stewart recalled being overwhelmed at first when he approached the site at the end of the seven-hour hike. Then, as dusk approached, the team investigated again.
“When the sun hits the bed, it explodes,” he says. “Immediately we were all stunned, and Pat said, ‘Bring your camera.’ We were stunned.”
In the second half Cretaceous At the time, the cliffs that make up the Coliseum were deposited on flat land near what was believed to be the watering hole of a vast floodplain. When the Earth’s plates collided and buckled to form the Alaskan Mountains, the previously flat ground collapsed and tilted vertically, exposing railroad-covered cliffs.
The tracks are a mixture of traces of ancient mud hardening and railroad molds that formed when sediments filled and hardened the tracks.
“They are beautiful,” Druckenmiller said. “You can see the shape of the toes and the texture of the skin.”
In addition to dinosaur footprints, the researchers found traces of fossilized plants, pollen grains and freshwater mollusks. invertebrate.
“All these little cues sum up what the whole environment looks like,” Stewart said.
He said the area was part of a larger river system, with nearby ponds and lakes. The region’s climate was warmer than it is today and resembled the Pacific Northwest. There were conifers and deciduous trees, and ferns and horsetails were abundant in the lower layers.
Footprints indicate that juvenile to adult dinosaurs frequented the area for thousands of years. The most common were large plant-eating duck-billed and horned dinosaurs. The researchers also documented rare carnivores such as raptors and tyrannosaurs, as well as small waders.
Druckenmiller said thousands of people visit Denali National Park and Preserve each year to experience the stunning natural scenery and environment. “It’s amazing to know that about 70 million years ago, Denali’s flora and fauna were just as impressive.
“It was forested and full of dinosaurs,” he said. “There were tyrannosaurs running around Denali that were many times the size of the biggest brown bears out there today. There were birds of prey. There were flying reptiles. There were birds. Great ecosystem.” did.”
Preserving fossil sites like the Coliseum is an important part of the National Park Service’s mission, said park geologist Denny Capps.
“On the one hand, we have to protect world-class fossil sites like the Colosseum from disturbance and theft,” he said. “On the other hand, we want visitors to see fossils in a geological context to better understand the evolution of landscapes and ecosystems over time while leaving them intact for others to appreciate. We recommend that you explore
Druckenmiller plans to continue working with the National Park Service to investigate the Coliseum and other stadium sites.
“The footprint survey in the park complements our research on dinosaur bones collected along the Colville River in northern Alaska,” Druckenmiller said. “Denali National Park and Preserve is a world-class dinosaur footprint area. We still have a lifetime to explore and wonder what other surprises await.”
Reference: “Vertebrate ichthyology and paleoenvironmental associations of the largest known Alaskan dinosaur footprint in the Cretaceous Cantwell Formation (Maastrichtian) of Denali National Park and Preserve.” Dustin G. Stewart, Patrick S. Druckenmiller, Gregory M. Erickson, Jeff A. Benowitz, Denny M. Capps, Cassandra L. Knight, Kevin C. May, Paul J. McCarthy, 27 July 2023, History biology.
DOI: 10.1080/08912963.2023.2221267
This research was funded by the National Science Foundation and the National Park Service.