Paleontology in Utah
[1] During the Precambrian, the area of northeastern Utah now occupied by the Uinta Mountains was a shallow sea which was home to simple microorganisms.
During the Permian the state came to resemble the Sahara desert and was home to amphibians, early relatives of mammals, and reptiles.
During the Triassic about half of the state was covered by a sea home to creatures like the cephalopod Meekoceras, while dinosaurs whose footprints would later fossilize roamed the forests on land.
Later, these lakes dissipated and the state was home to short-faced bears, bison, musk oxen, saber teeth, and giant ground sloths.
During the Precambrian, the area of northeastern Utah now occupied by the Uinta Mountains was a shallow sea which was home to simple microorganisms.
Cambrian fossils are known from Antelope Springs, the House Range, Millard County in west central Utah.
[3] One spectacular fossil trackway from this formation documents a possible predation event that occurred hundreds of millions of years ago.
[4] Sea levels in Utah dropped by the start of the Mesozoic, leaving only the western half of the state submerged.
One small individual preserved in sediments now known as the Entrada Sandstone represents the only vertebrate body fossils known from western North America.
[5] The Entrada Sandstone also preserves many footprints of mid-to-large sized carnivorous dinosaurs across more than thirty tracksites in the eastern part of the state.
[2] The Uinta Basin region near the state's border with neighboring Wyoming has been a source of fossil bird tracks, fish, insects, and leaves dating back to the Eocene epoch of the Cenozoic era.
Local wildlife included short-faced bears, bison, musk oxen, saber teeth, and giant ground sloths.
[11] Between the years 700 and 1,000 the Fremont culture left petroglyphs of giant lizards up to six feet long next to a small one foot tall human figure at Cub Creek, not far from the Douglas/Carnegie bone beds of Dinosaur National Monument.
Alternatively, the lizard petroglyphs may have been inspired by fossil footprints of the ichnogenus Brachycheirotherium, which is sometimes accompanied by lizard-like tail drag marks.
The traditional way of making an Elrathia amulet necklace was to fix thirteen specimens in order of increasing size with green, red, and brown beads made of clay accompanied by two horsehair tassles on a leather thong.
[13] The idea of trilobite amulets as having protective power may have been inferred from the resilience of the stone surrounding an animal resembling a "normally vulnerable" water bug.
In September, Holland suggested that Douglass search for Jurassic dinosaur fossils in the Uinta Mountains north of his camp.
Previous surveyors and paleontologists had noted dinosaur fossils of that age there and Holland suspected that they were promising hunting grounds.
Douglass had little luck during the spring and early part of the summer, but on August 17 he found a series of eight fossil Apatosaurus tail vertebrae, still articulated.
[16] Among his finds were two more adult Apatosaurus and one juvenile, and the partial skeletons of Allosaurus, Barosaurus, Camarasaurus, Camptosaurus, Diplodocus, Dryosaurus, Stegosaurus.
[18] In 1915 US president Woodrow Wilson declared the quarry and surrounding land Dinosaur National Monument in order to protect it from settlement.
