Welcome back everyone! In this installment of Dinosaurs of Utah we are going to cover probably the most famous carnivore of the Jurassic period. Allosaurus Fragilis was named by Othniel Charles Marsh in 1877. The name means ‘Different Lizard‘ and was found in Utah’s Cleveland-Lloyd Quarry, a site containing the densest concentration of Jurassic dinosaur bones in the world. Of the at least 74 individual dinosaurs found at the quarry, about 46 of them are Allosaurus specimens, according to the U.S. Bureau of Land Management.
Allosaurus ranged from about 28 to 43 feet (8.5 to 13 meters) long, and any where between 10 to 16 feet ( 3 to 5 meters) tall and weighed around 1.6 tons (1700 kg). Allosaurus had 10 inch razor sharp claws on their three digit hands, they also had a mouth full of serrated razor sharp teeth (between 14 and 17) and their jaw could open to roughly to a 79 degree angle. This may have given them an advantage in taking down some of their largest prey including the giant sauropod Apatosaurus.
Speaking of Allosaurus’ prey number one on their list seems to have been the armored dinosaur Stegosaurus. There is proof of this found in the fossil record. There way an Allosaurus vertebra found with a puncture wound inflicted from the tail spike (Thagomizer) of a Stegosaurus, along with this there have been Stegosaurus fossils found with bite wounds that line up with that of an Allosaurus. The way that Allosaurus’ teeth were indicated that instead of the crushing through skin and bone, like the T-Rex, it stripped the flesh from its food. Evidence of this can be found in many sauropod fossil remains.
Allosaurus became the Utah state fossil in 1988 and can be seen in pretty much and dinosaur museum in Utah. At Dinosaur National Monument outside of Vernal, Utah you can see a real Allosaurus skull at the Carnegie Quarry wall. If you have been there or anywhere else that has an Allosaurus please send us your pictures in the comments!