SciTechDaily has a story about Utahraptor.  New research by paleontologists (one at the University of Kansas) shows that Utahraptor actually lived about 135 million years ago, not 125 million years as previously thought.  Utahraptor is the largest known “raptor” dinosaur at 4.9–5.5 m (16–18 ft) long and weighing 280–300 kg (620–660 lb).  It’s also one of the oldest members of the family Dromaeosauridae.  It was discovered in October 1991 by James Kirkland, Robert Gaston, and Donald Burge uncovered further remains of Utahraptor in 1991 in the Gaston Quarry in Grand County, Utah, within the Yellow Cat and Poison Strip members of the Cedar Mountain Formation.  Read all the details in the paper “Berriasian–Valanginian Geochronology and Carbon-Isotope Stratigraphy of the Yellow Cat Member, Cedar Mountain Formation, Eastern Utah, USA”, which was published in the journal Geosciences.

Utahraptor is going to need 10 million more candles on its next birthday cake.

A geological study of the rock formation that encased a fossilized example of the world’s biggest “raptor” shows it’s 10 million years older than previously understood. The report, co-written by a researcher with the University of Kansas, was recently published in the journal Geosciences.

“We determined the age of the dinosaur Utahraptor and found that it was much older than previously supposed,” said Gregory Ludvigson, emeritus senior scientist with the Kansas Geological Survey at KU, who collaborated on the investigation. “That finding has important implications for the evolutionary history of dinosaurs.”

The fieldwork took place in Utah at the well-known Utahraptor Ridge site, named for larger cousins of the ferocious velociraptor dinosaur (known to fans of “Jurassic Park”).

The ridge is home to Stikes Quarry, a fossil quicksand deposit packed with dinosaur fossils that are largely intact and preserved — in much the same positions as when they died. Stikes Quarry is part of the Cedar Mountain Formation, a rock unit containing fossils of more kinds of dinosaurs than any formation in the world.