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| Bones of several different types of Jurassic dinosaurs including Allosaurus, Stegosaurus, Camarasaurus, and Camptosaurus can be seen along the Mill Canyon Dinosaur Bone Trail. |
Moab has a lot going for it.
The small town of Moab is located in one of the most scenic areas in the United States with two national parks and two state parks nearby. Surrounded by public lands, it offers ample opportunities for river running, hiking, rock climbing, jeeping, and sightseeing. The town has a great public library, a museum, an excellent independent bookstore, critically-acclaimed folk and classical music festivals, two separate art festivals, a festival of science, and more. In addition all these great things, Moab is also located in the heart of one of the most significant areas for dinosaur paleontology in the country with many important dinosaur fossil localities.
Dinosaurs were a diverse group of terrestrial vertebrates that (with the exception of birds) became extinct 66 million years ago. Dinosaurs all evolved from a common ancestor, but then diverged into a large group with differing body sizes and physical characteristics.
Dinosaurs do share several characteristics with one another: they stood on upright limbs (versus having a sprawling stance with legs off to their sides like lizards and other reptiles), they had distinctive elements to their skull and pelvis, and they laid eggs.
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| A restoration of Gastonia, a dinosaur discovered in the Cedar Mountain Formation near Moab. Credit: Public domain by Mariana Ruiz LadyofHats. |
Why are there so many dinosaur fossil sites in southeastern Utah? In short, because the area contains the right rocks. For dinosaur fossils, the right rocks means rock layers (formations to geologists) of Mesozoic age that were deposited in environments in which dinosaurs lived (e.g., terrestrial) and where evidence of their life (trace fossils) or their remains (body fossils) were preserved.
Except some older rocks found in places like deep canyons (like Cataract Canyon), Mesozoic rocks are exposed in the Moab area. The Mesozoic Era is popularly known as the Age of the Dinosaurs because dinosaurs were the dominant land vertebrates then. The Mesozoic Era ranges from 252 to 66 million years ago and consists of three geologic periods: the Triassic, Jurassic, and Cretaceous. Moab has dinosaur-bearing rocks of all three periods. This great range in age of Moab’s Mesozoic rocks adds to the diversity of dinosaur fossils that have been discovered here as each period had a distinctive dinosaur fauna.
Almost all of the Moab area’s twelve different Mesozoic rock layers were
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| Therapod track from the Mill Canyon Dinosaur Tracksite. |
deposited in continental environments versus marine (ocean) ones. The Chinle, Kayenta, Morrison, and Cedar Mountain formations were deposited mostly by rivers and on their floodplains—all environments that provided excellent habitat for dinosaurs. The Wingate, Navajo, Entrada, and the Moab Member of Curtis Formation were eolian in origin, meaning that they were deposited by wind in sand dune fields. These environments were not as receptive to dinosaurian life as the ones in river valleys, but interdunal lakes provided some excellent habitat, and dinosaur fossils are known from all of the eolian layers except for the Entrada Sandstone.
Both body fossils and trace fossils (ichnofossils) have been found near Moab. Body fossils include bones, teeth, and skin impressions, although bones and teeth are much more commonly preserved than soft body parts like skin. Several dinosaur quarries have been located near Moab, with particularly significant ones in the Cedar Mountain Formation, including in the newly established Utahraptor State Park. The Cedar Mountain Formation is especially of interest to paleontologists as it has one of the most important dinosaur faunas on the entire continent.
Moab is particularly rich in fossil tracksites. At least eight different rock layers found near Moab contain fossil trackways. With at least six different tracksites that have developed trails and/or educational exhibits, Moab is also one of the best places in the country to see these tracks of the past.
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| A restoration of Gastonia, a dinosaur discovered in the Cedar Mountain Formation near Moab. Credit: Public domain by Mariana Ruiz LadyofHats. |
Tracksites are especially critical for understanding dinosaurian behavior because they record the life activities of the animals that left them. For example, the Copper Ridge Dinosaur Tracksite contains tracks of a large sauropod (four-legged dinosaur herbivore) making a right turn and those of a therapod (three-toed dinosaur carnivore) with a limp.
Three of the area’s best known tracksites (Dinosaur Stomping Ground, Willow Springs, and Bull Canyon) are part of the Moab Megatracksite. The megatracksite is a regionally extensive surface in the Curtis Formation (Moab Member) that contains thousands of dinosaur tracks, mostly from therapods, that were formed when the animals walked across a coastal plain.
Together, research at Moab’s dinosaur bone quarries and tracksites continue to add to our understanding of life during the Mesozoic. And with so many sites with educational signs and interpretive trails that allow people to view dinosaur bones and tracks in situ (in place), Moab is also an amazing place for dinosaur tourism and education. For many people, the thrill of being able to see a dinosaur bone embedded in sandstone surrounded by the breathtaking canyon country scenery may rival that of running a rapid on the Colorado River or doing any of the other great things that Moab offers. Once dinosaurs are added into the mix, Moab really has a lot going for it.
All fossils on federal public lands provide important insights into past life and are protected by the Paleontological Resources Protection Act.
Special thanks to Jim Kirkland, Utah State Paleontologist.
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A self-described “rock nerd,” Allyson Mathis is a geologist, informal geoscience educator and science writer living in Moab.