Martharaptor was a therizinosaur theropod dinosaur which lived in Utah during the early Cretaceous Period approximately 135-132 million years ago. Therizinosaurs are known mostly from the middle and later parts of the Cretaceous Period. Fossils dating to the early Cretaceous… Read More ›
Cedar Mountain Formation
Cedrorestes
Cedrorestes, which means “Cedar Mountain dweller”, was an ornithopod dinosaur which lived in Utah during the early Cretaceous Period. The fossils of this animal were discovered in eastern Utah in 2001. These were fragmentary remains consisting of pieces of ribs,… Read More ›
The Choristoderan of the Cedar Mountain Formation
The Cedar Mountain Formation of eastern Utah contains rock layers dated to the early and middle Cretaceous Period, approximately 144-95 million years ago. Most of the fossils found here belong to medium-sized and large-sized dinosaurs, while fossils belonging to smaller… Read More ›
Mierasaurus
Mierasaurus was a turiasaurian sauropod dinosaur which lived in Utah during the early Cretaceous Period approximately 139 to 136 million years ago. Mierasaurus lived during a time when the environment of prehistoric Utah became substantially wetter and more humid than… Read More ›
Hippodraco
Hippodraco, meaning “horse dragon” in a mixture of ancient Greek and Latin, was an ornithopod dinosaur which lived in western North America during the early Cretaceous Period. The fossils were found by Andrew R. C. Milner in 2004 in east-central… Read More ›
Falcarius
Falcarius was a 12 foot long theropod dinosaur which lived in Utah during the early Cretaceous Period, approximately 139 to 136 million years ago. It was a very primitive therizinosaur – so primitive that it still bears a close resemblance… Read More ›
Polyacrodus
NOTE: This article was originally published on May 4, 2022. On December 30, 2025, it was updated and re-uploaded. Polyacrodus was a genus of prehistoric shark, composed of several species, with fossils found in North America, South America, Europe, Asia, and… Read More ›
Cretaceous Stegosaurs in North America? Maybe
Stegosaurus stenops. © Jason R. Abdale (August 1, 2020) Stegosaurus is one of the most famous dinosaurs in the world. With its large back plates and spiked tail, it’s commonly seen in every child’s dinosaur book and is one of… Read More ›
The Cedar Mountain Allosaur
The Cedar Mountain Formation is a geological formation located in the western United States, mostly within the state of Utah, with rocks dating to the early and middle parts of the Cretaceous Period. The Cedar Mountain Formation is most well-known… Read More ›
Nedcolbertia: A North American elaphrosaur?
IntroductionNedcolbertia (named in honor of the American paleontologist Dr. Edward “Ned” Colbert, 1905-2001) was a mysterious and intriguing creature which inhabited western North America during the early Cretaceous Period about 140-130 million years ago. When it was officially named and… Read More ›