Researchers reported in a new study, titled "Berriasian-Valanginian Geochronology and Carbon-Isotope Stratigraphy of the Yellow Cat Member, Cedar Mountain Formation, Eastern Utah, USA" published in the journal Geosciences, that the age of the world's biggest raptor is 10 million years older than previously believed.
The findings were brought upon a geological study of the rock formation that preserved its fossil. Gregory Ludvigson, an emeritus senior scientist with the Kansas Geological Survey at KU who worked on the study, stated that the finding has important implications for the evolutionary history of dinosaurs.
The head of a replica of the dinosaur Austroraptor cabazai is silhouetted against a projection screen at the Argentine Museum of Natural Science Bernardino Rivadavia in Buenos Aires on December 17, 2008.
Utahraptor Fossils Found in Rock Formations
Scientists have discovered that the dinosaur, Utahraptor, is much older than previously thought. Gregory Ludvigson, an emeritus senior scientist with the Kansas Geological Survey at KU, said this finding has significant implications for the evolutionary history of dinosaurs.
According to Phys.org, the team conducted fieldwork at the Utahraptor Ridge site in Utah, where they found Stikes Quarry, a fossil quicksand deposit with largely intact dinosaur fossils. The quarry is part of the Cedar Mountain deposit, which has more dinosaur fossils than any other deposit on the planet.
Scientists were shocked to discover that the rock layers from the Stikes Dinosaur Quarry were deposited during the Weissert Event, a period of worldwide upheaval. Over a decade ago, Ludvigson, along with state paleontologists Jim Kirkland and Matt Survey teamed up to tackle the question of the dinosaur's age.
The scientists employed two study methods to calculate the dinosaur's age. The first method involves evaluating uranium/lead dating samples of zircon crystals obtained at various depths in the rock strata, while the second method examined variations in the relative abundance of two types of stable carbon isotopes found in buried organic materials.
The study demonstrated that rocks in the Yellow Cat Member of the Cedar Mountain Formation and the Utahraptor fossils found therein are 10 million years older than previously assumed by comparing results to eras in Earth's history when worldwide disruptions in the carbon cycle were known to have occurred.
According to the revised age, the rocks in Stikes Quarry are at least 135 million years old. The findings also narrow the gap in the rock record at the boundary between the Jurassic and Cretaceous Periods in Utah and shed light on the evolution of dinosaurs.
Kirkland, who first named and described the dinosaur Utahraptor ostrommaysi in 1993, said that before the discovery, there was a 25-million-year gap between the two periods. This gap is a significant chunk of time, and the researchers have finally filled it for the most part.
More About the World's Biggest Raptor
Utahraptor is a type of carnivorous dinosaur and is known for being one of the largest and oldest dromaeosaurids, a group that had a retractable claw specialized for cutting. According to the Natural History Museum of Utah, its name translates to "Utah's predator," and it was a fierce hunter that used its sickle-shaped claw to attack and tear apart its prey.
The size of the claw was remarkable, measuring 9.5 inches (24 cm) in length. The species was named after Dr. John Ostrom of Yale University, who linked carnivorous dinosaurs to the ancestry of birds through his research.
The Velociraptors portrayed in the film Jurassic Park were patterned after Utahraptor; however, mature specimens of Utahraptor were significantly larger than the fictitious species, measuring roughly 20 feet (6.1 meters) long and 5 feet (1.5 meters) tall at the hip.
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