Dinosaurs & Fossils

Dinosaurs lived only during the Mesozoic Era, which is often called the “Age of Dinosaurs.” Utah has perhaps the best Mesozoic rock record in the world. Other Mesozoic fossils found in Utah include remnants of marine and land plants and animals. Utah is also home to Ice Age fossils, tracks and tracksites, petrified wood, and trilobites.

Utah Dinosaurs

Survey Notes 47-3 Megablock

A reconstruction of the Stikes dinosaur death trap. Adult and juvenile Utahraptor dinosaurs attack an iguanodont dinosaur trapped in quicksand. By Julius Costonyi.

Dinosaurs lived during the Mesozoic Era, more specifically, the Triassic, Jurassic, and Cretaceous Periods. In Utah, dinosaurs from the Jurassic and the Cretaceous have been found and described.

Dinosaurs are divided into two major groups, the saurischian, or “lizard-hipped,” dinosaurs and the ornithichian, or “bird-hipped,” dinosaurs.

  • The saurischian dinosaurs include the herbivorous (plant-eating), quadrupedal (four-footed) sauropods, and the carnivorous (meat-eating), bipedal (two-footed) theropods.
  • The ornithichian dinosaurs are all herbivorous and are composed of many groups, including stegosaurs, ornithopods, and ceratopsians.
Click here to go to the Dinosaurs of Utah poster.

Fossils in Utah

A wide variety of fossils are found in Utah. Some of the most common fossils are of marine life like shells, fish, and trilobites. Land plant and animal fossils are also found in Utah and include dinosaurs, Ice Age animals, and leaves. Scroll through the timeline below to see Utah’s fossils and fossil environments from millions to hundreds of millions of years ago.

Utahraptor Megablock Fossil Project

Scott Madsen working on the megablock at the UGS.

The Utah Geological Survey (UGS) holds on behalf of the citizens of the State of Utah what is likely the most spectacular dinosaur fossil assemblage ever collected in the state. Recovered from the Stikes Quarry in southeastern Utah, the 9-ton block of sandstone contains thousands of bones of baby to adult Utahraptor dinosaurs, at least two iguanodont dinosaurs, and possibly other species. These animals became trapped in a quicksand-like mass likely while preying on one or more trapped plant-eating iguanodont dinosaurs. Many painstaking hours have been spent by expert preparators carefully exposing hundreds of bones from just a small portion of the accumulation of skeletons. The megablock is yielding numerous juvenile and adult skeletons that will be reassembled into a pack of Utahraptor dinosaurs and displayed at the Natural History Museum of Utah.

Learn about the 9-ton megablock of Utahraptor dinosaur fossils being prepared at the UGS.

Tracks & Other Trace Fossils

Trace fossils include evidence left by organisms but not the remains of body parts such as bones or shells. Examples of trace fossils include burrows, trails, scat, claw scratch marks, footprints, tail drags, and skin and body impressions. Tracks and other trace fossils can be good evidence for the size and identity of the animals that made them. Behaviors like eating habits, migration paths, and walking mechanics can also be inferred from some tracks if they are well preserved.

Tracks are formed and preserved by footprints left in mud, silt, or sand being filled in and buried. These layers of sediment later turn to stone with time and deeper burial. When subsequently exposed by erosion, often the prints themselves are not preserved but rather the infilled material is. Thus, many tracks are not found as impressions, but bumps (natural casts) on the underside of the stone layers that overlie the tracks.

In Utah, tracks can be found in many places such as the St. George Dinosaur Discovery Site at Johnson Farm and at Flaming Gorge Reservoir. Visit our interactive map to locate and visit some tracksites for yourself!

Fossil Mountain, Millard County, Utah Landforms, Fossils 2023
The Utah Geological Survey and the National Park Service Dinosaurs and Fossils 2023
Paleo News: New Discoveries of Morrison Formation Plant Fossils Expand Our Knowledge of Jurassic Ecosystems Plant Fossils 2022
Cannonball Concretions in a Treeless “Buried Forest,” Carbon County, Utah Landforms 2021
Needing a Great Resource for Teaching Your Students About Utah Fossils? Technology 2020
Utah’s Early Cretaceous Fossils Provide Critical Data on the Opening of the Atlantic Ocean Dinosaurs 2018
Mysteries of the Uinta Mountains – Commonly Asked Questions Mountains 2018
Parowan Gap, Iron County Landforms 2018
Does Utah Preserve North America’s Oldest Cretaceous Dinosaurs Because of Ancient Salt Deposits? Dinosaurs 2017
Wolverine Petrified Forest, Garfield County Fossils 2017
UGS Paleontologists Collect Dinosaur Megablock Dinosaurs 2015
St. George Dinosaur Discovery Site at Johnson’s Farm, Washington County Tracks 2014
When sharks, rays & sawfish ruled Utah’s rivers Fossils 2014
Spectacular pterosaur track slab begins its cross-country journey Tracks 2013
The Thumb-Spiked Iguanodontians – Dinosaurian Cows of the Early Cretaceous Dinosaurs 2013
UGS Scientist Honored in Naming of Utah’s Newest Dinosaur: Martharaptor greenriverensis Dinosaurs 2013
Are those animal tracks in the sidewalk? Tracks 2012
Utah’s Prehistoric Tanks: The Ankylosaurs Dinosaurs 2011
Utah’s Pleistocene Fossils: Keys for Assessing Climate and Environmental Change Ice Age 2010
Utah’s Glacial Geology Glaciers 2010
The fossil preparation lab at the Utah Geological Survey: Bringing Earth’s ancient past to life Fossils 2010
Ice Ages – What are they and what causes them? Ice Age 2010
Glacial Landforms in Big and Little Cottonwood Canyons Glaciers 2010
What should you do if you find a fossil? Can you keep it? Should you report it? Fossils 2009
Scientific Investigations at Hanksville-Burpee Dinosaur Quarry Dinosaurs 2009
Fossil environments in Utah (pdf) Fossils 2008
G.K. Gilbert Geologic View Park, Salt Lake County Landforms 2008
Glacial striations and slickensides – What are those groovy rocks and how did they get that way? Glaciers 2008
The Case for Fishing Dinosaurs Tracks 2007
New Horned Dinosaurs from the Wahweap Formation Dinosaurs 2007
New Discoveries of Fossil Mammals Fossils 2006
Dinosaur Record from the Early Cretaceous Cedar Mountain Formation Dinosaurs 2005
Utah’s Newly Recognized Dinosaur Record Dinosaurs 2005
Falcarius utahensis; Killer Dinos Turned Vegetarian Dinosaurs 2005
Inventory and Management of Utah's Fossil Resources Fossils 2005
Utah’s oldest fossils are found in the Uinta Mountains Fossils 2005
Are there glaciers in Utah’s mountains? Glaciers 2003
The Wolverine Petrified Forest Fossils 2003
Rules and Regulations Regarding Rock, Mineral, and Fossil Collecting in Utah Rocks and Minerals 2003
Discovery of a New Pterosaur Tracksite at Flaming Gorge Reservoir Tracks 2002
St. George Dinosaur Tracksite Tracks 2002
Pahvant Butte in the Black Rock Desert Volcanoes 2002
Utah’s Wildlife in the Ice Age Ice Age 1996
Trilobites and the Cambrian Environment of Utah Fossils 1996
Special Issue on Utah Minerals, Fossils, Geology Rocks and Minerals 1994
The geologic story of GK Gilbert Geologic View Park Geologic History
Mammoth tusk discovery adds to our knowledge of life along the shores of Lake Bonneville Ice Age
Squatting Dinosaur Tracks Tracks
St. George Dinosaur Tracksite (pdf) Tracks
Dinosaurs Making Tracks at Flaming Gorge Reservoir Tracks

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