Introduction The Hell Creek Formation of the western United States is understandably known for its dinosaur fossils, including Tyrannosaurus and Triceratops. However, in terms of sheer physical numbers, there are other species found here which surpass them by far. One… Read More ›
Prehistoric
Arthropterygius
Arthropterygius, “jointed fin”, was a genus of ichthyosaur which lived in the Arctic Ocean during the Jurassic/Cretaceous transition period about 150 to 140 million years ago. Fossils of it have been found in Canada, Scandinavia, and Russia, and bones which… Read More ›
Semionotus
Semionotus was a genus of prehistoric fish which lived throughout the world during much of the Mesozoic Era. It was named by the famous Swiss ichthyologist and paleontologist Louis Agassiz in 1843 (type species: Semionotus bergeri). Semionotus first appeared during… Read More ›
The Big Muddy: The Mowry Sea of the Early Cretaceous Period
Today the broad expanse of the Great Plains, which forms the central part of North America, is a vast area of farms, prairies, and deserts. Here, immense herds of buffalo once roamed and wild mustangs galloped. However, the land did… Read More ›
Astrodon
If you were to ask people if they know a good place to find dinosaur bones, many of them would say “Go west, young man!” There is a lot of truth to this. There are vast areas of western North… Read More ›
Altispinax: The Mysterious Meat-Eater of Early Cretaceous England
Introduction There are many dinosaur species which have been identified based upon very scant remains, and this article concerns one of them: a meat-eating dinosaur named Altispinax dunkeri. If you’ve never heard of this animal before, you’re not alone. It’s… Read More ›
Brachiosaurus
There are some dinosaurs that everybody thinks of when they hear the word “dinosaur”. Among these is a very large sauropod which was the reptilian analog of a giraffe. I am, of course, talking about Brachiosaurus. Brachiosaurus is one of… Read More ›
List of Articles about the Morrison Formation
The Morrison Formation of western North America is my favorite geological / paleontological formation to study. Within these rock layers, which are dated to the late Jurassic Period from approximately 155 to 145 million years ago, are found the fossils… Read More ›
Morrolepis
Note: This article was originally published on August 31, 2019. It has since been substantially updated and re-published on September 19, 2024. The Morrison Formation of the western United States is one of the most famous deposits of late Jurassic… Read More ›
Harpactognathus
Harpactognathus was a rhamphorhynchid pterosaur which lived in the Morrison Formation of western North America during the late Jurassic Period. It was one of the largest pterosaurs that lived in North America during that time. Although it is only known… Read More ›