Serratolamna was a genus of prehistoric shark which lived from the late Cretaceous Period to the Eocene Epoch of the Paleogene Period, approximately 75-45 million years ago. The genus is currently divided into several species, of which the species S…. Read More ›
North America
Didelphodon
Didelphodon, known largely from its appearance as a background character in the final episode of the 1999 BBC series Walking with Dinosaurs, was a large prehistoric mammal which lived in North America during the late Cretaceous Period 73-66 million years… Read More ›
Cimoliasaurus
Cimoliasaurus, meaning “chalk lizard” due to its fossils being found within layers of chalk, was a genus of elasmosaurid plesiosaur which lived at the end of the Cretaceous Period 70-66 million years ago, making it one of the last plesiosaurs… Read More ›
Mosasaurus
Mosasaurus was a genus of fully-aquatic marine lizards which lived throughout the world’s oceans during the late Cretaceous Period approximately 75-66 million years ago. Fossils of this animal were first discovered in 1764 within a chalk mine in the town… Read More ›
Online Lecture Series: “Utahraptor’s World: North America during the early Cretaceous Period 135 million years ago”
Hello. On August 21-23, 2024, I hosted a three-part Zoom lecture series on what North America looked like during the time that the dinosaur Utahraptor was alive during the early Cretaceous Period 135 million years ago. Utahraptor’s fossils are currently… Read More ›
Apsopelix and Pelecorapis: Two Separate Genera, Or Just One?
Introduction Apsopelix and Pelecorapis were two genera of closely-related prehistoric saltwater fish which lived during the middle to late Cretaceous Period. Fossils of Apsopelix have been found in England, France, and in the American states of Montana, South Dakota, Colorado,… Read More ›
Siats
Introduction Siats, whose name is in reference to a monster from native Ute folklore, was a large meat-eating dinosaur which lived in Utah during the middle Cretaceous Period 98 million years ago. As far as we know, Siats was the… Read More ›
Gastonia
Introduction Gastonia was an armored dinosaur measuring approximately 16.5 feet long which lived in western North America during the early Cretaceous Period approximately 135-130 million years ago. The first specimens were found in eastern Utah in 1989, and more have… Read More ›
Thalassomedon
Thalassomedon, meaning “lord of the sea”, was a 38 foot long elasmosaurid plesiosaur which lived within the Mowry Sea, the shallow sea that covered North America during the middle of the Cretaceous Period 97-95 million years ago. In March 1939,… Read More ›
Edgarosaurus
Edgarosaurus was a 12 foot long short-necked plesiosaur which lived within the Mowry Sea during the middle Cretaceous Period 105-100 million years ago. In 1993, a well-preserved fossil specimen consisting of the skull, neck, and one front flipper (collection ID… Read More ›