ROCKINGEOLOGY.COM

The word dinosaurs for most of us congers up a feeling of large, huge, dangerous and ferocious, and the word dinosaur means “terrible lizard”, it fits our mental visual image of the term. The word “Utah” makes most people think of Mormons and other things like Zion’s park or Bryce’s canyon or the Great Salt Lake. But for those of us in the know think of dinosaurs, trilobites, fossil fish and petrified wood. Utah has some of the best geology in the world and some of the best fossils in the world you can not separate the two. One hundred and fifty million years ago dinosaurs roamed most of Utah and dinosaur bones were deposited in the famous Morrison formation along with other fossils such as fish, crocodiles, frogs, insects, turtles and very small mammals. The Morrison formation consisted mostly of sandstones, shale’s, conglomerates and mudstone. The Morrison formation was deposited on a low sloping plane sloping mostly to the east. Large slow moving rivers deposited most of sediments in the Morrison formation as they meandered east ward along a floodplain. Many lakes dotted the landscape volcanoes erupted west of the Morrison depositional basin mixing volcanic ash in the Morrison sediments. The evidence suggests that the environment was semi-arid and that there was dry and wet seasons. Utah lay closer to the equator at this time due to the North American plate called Laurasia shifting around like a large ocean liner cutting through the ocean.

Dinosaurs found in the Morrison formation of the Mesozoic era include the theropod Allosaurus the Utah state fossil. This was the largest predator Dinosaur found in the Morrison formation and is found in large numbers at the Cleveland-Lloyd dinosaur quarry near Price, Utah. It attained a length of 40 feet and rightly should have been the star of the movie “Jurassic park” instead of Tyrannosaurus Rex Dinosaur, because Tyrannosaurus Rex never lived during the Jurassic time period. Other dinosaurs found in the Morrison formation include the sauropod Dinosaur Apatosaurus. A 90 foot long dinosaur and Brachiosaurus who weighed in at 100 tons or more and was the largest living dinosaur ever to be found in the Morrison formation. Other dinosaurs are Diplodocus which was found at Dinosaur national monument near vernal Utah. This dinosaur was 87 feet in length. Stegosaurus was the plated dinosaur.

There are two major dinosaur quarries in Utah and many smaller dinosaur quarries. Ten museums located in Utah. Four dinosaur track sites are found here as well. The Cleveland-Lloyd dinosaur quarry is located south of price. Here the Dinosaurs were trapped in mud at the bottom of a small lake and other meat eating dinosaurs seeing they were in distress waded in after them only to be caught in the mud as well. Fourteen varieties of dinosaurs have been found, but most of the dinosaur bones found belong to the carnivorous dinosaur Allosaurus. Dinosaur national monument lies about 20 miles north east of vernal Utah and is literally a wall of dinosaur bones. These dinosaurs died and were washed in to a moderately sized meandering river and there bones were washed down stream to the east till they dammed up against each other in the river and were covered over with sediment and buried till paleontologists uncovered the dinosaur bones 150 million years later.

Near St. George Utah at the Johnson farm dinosaur track site you can see dinosaur tracks, dinosaur swim tracks, and dinosaur tail tracks left in the fossilized mud from an ancient lake that formed in the monave formation of the lower Jurassic period.