The lost world of northern dinosaurs
Ned Rozell
907-474-7468
Aug. 30, 2024
Florida State University graduate student Tyler Hunt scans a rock that contains several dinosaur footprints during a recent trip on the upper Colville River.
On a recent river trip in northern Alaska, scientists from the University of Alaska Museum of the North found a lost world, a time of “polar forests with reptiles running around in them.”
That’s a description from Patrick Druckenmiller, director of the museum and a paleontologist with the ability to look at river rocks and see the footprints of an animal that walked there from 90 million to 100 million years ago.
A star on a map of Alaska shows the location of the upper Colville River.
In early August 2024, Druckenmiller and his colleague Kevin May, along with Greg Erickson and Tyler Hunt of Florida State University, floated 160 miles along the upper Colville River on Alaska’s North Slope. There in the rocks on the shoreline, they found fossilized tracks of many species of dinosaurs, as well as the pebbled skin impressions left behind by an armored ankylosaur and other plant-eating dinosaurs.
They captured many images of this very different time and also returned to ̳ with a few hundred pounds of fossils on their chartered aircraft.
With that evidence — including etchings of ginkgo leaves that would most certainly not grow on the North Slope today — Druckenmiller hopes to piece together a long-gone ecosystem.
“The dinosaur story in the state from the end of the Cretaceous (70 million years ago) is well known because of the Prince Creek Formation (on the lower Colville River) and Denali National Park and Preserve,” Druckenmiller said. “The older period (from 90 million to 100 million years ago) is very poorly known. And it’s a really warm interval in Earth’s history.”
Ninety million to 100 million years since it last pulled in carbon dioxide, a ginkgo leaf fossil remains on a rock of the upper Colville River.
How warm was today’s cold North Slope back then? From the broadleaf plant fossils and petrified tree stumps the team members found, Druckenmiller estimates the upper Colville River area had a similar climate to Washington state today.
“And (the upper Colville) was farther north at the time,” he said. “It has moved south since then (due to movement of tectonic plates), which makes it all the more remarkable.”
North of the Brooks Range — the farthest north of Alaska’s three major sweeps of mountains