Imagine widespread, humid forests with old, venerable trees, an undergrowth of moisture-loving plants and massive dinosaurs prowling about, along with various other species.
It doesn’t seem like it now, but that’s exactly what northeastern Utah near Red Fleet State Park may have looked like during the Late Jurassic period — approximately 150 million years ago — according to new fossil findings from a team of paleontologists.
“It’s neat to know that there was a time in what is now kind of high desert where you had big trees, creating a nice shaded forest floor,” said John Foster, one of the paleontologists involved in the discovery.
The team, from the Utah Division of State Parks and the University of Bonn, Germany, excavated near and on the shores of Red Fleet Reservoir. It’s located several miles west of the Dinosaur National Monument, where dinosaur remains from the Late Jurassic period can be seen.
At the site, the team dug up fossilized leaves, as well as pollen samples and silicified logs that indicate the presence of a humid forest.
The team also discovered bones belonging to long-necked and carnivorous dinosaurs, as well as two leg bones from small bipedal herbivores known as dryosaurs.
“The bones at the site are in poor condition,” stated Steve Sroka, Park Manager at Utah Field House in a news release. “Preservation conditions favorable for bones are typically detrimental to plants, and vice versa.”
The fossilized leaves collected so far suggest the presence of several types of ferns, as well as now-extinct seed ferns, ginkgophytes, cycads, horsetail; and araucarian conifers. It’s assumed that the ancient forest was formed by the taller trees, with a lush understory made up of ferns and other plants.
“The animals that we found there are all terrestrial animals,” Foster said. “We haven’t really seen anything aquatic, so it seems to be a forest similar to some of the bigger forests that you get today.”
The fossilized leaves were well-preserved when the team found them — so much so that their waxy cuticles are still intact, preserving the original leaves’ underlying cell structure.
“We were pleasantly caught off guard when the first leaf cuticle emerged, as we hadn’t found many specimens at that point,” Foster, who also serves as a curator with the Utah Field House of Natural History State Park Museum, said in a news release. “We had to act quickly to preserve the fossil leaves before the cuticle dried out and dispersed.”
The site where the fossils were found was initially discovered in the late 1980s but has only recently been extensively explored for its plant material. Previously, Late Jurassic leaf findings were predominantly located in Montana and Colorado, according to Carole Gee, a paleobotanist from the University of Bonn, Germany.
Preliminary findings from the team’s research were presented at a Mesozoic Terrestrial Ecosystems conference in Salt Lake City earlier this month.
Foster said he hopes to continue exploring the area in the fall, if the water levels are low enough.