A recent study published in the journal Geosciences reveals that the fossilized Utahraptor, the world’s largest “raptor,” is actually 10 million years older than previously thought. The study, co-authored by a University of Kansas researcher, sheds new light on the evolutionary history of dinosaurs.
The research was conducted at the Utahraptor Ridge site in Utah, which is home to Stikes Quarry, a fossil deposit containing largely intact dinosaur fossils preserved in their original positions. The site is part of the Cedar Mountain Formation, which boasts the most diverse range of dinosaur fossils of any formation in the world.
The team used two research approaches to determine the fossil’s age. The first involved analyzing samples of uranium/lead dating of zircon crystals, while the second analyzed changes in the relative abundance of two types of stable carbon isotopes found in buried organic matter. The findings indicate that the Utahraptor fossils are at least 135 million years old, which is 10 million years older than previously believed.
The revised age narrows the gap in the rock record at the boundary between the Jurassic and Cretaceous Periods in Utah, which was previously a 25-million-year gap. This new discovery will have significant implications for understanding the evolutionary history of dinosaurs and the impact of global changes on the Earth’s history.