An ornithocheirid pterosaur. © Jason R. Abdale (February 13, 2022). The “ornithocheirids” were a group of pterosaurs which dominated the skies during the early and middle parts of the Cretaceous Period from about 140 to 90 million years ago. They… Read More ›

North America
The Sail-Backed Dinosaur from the Cedar Mountain Formation
Greetings. A few days ago, I learned of a remarkable discovery. In east-central Utah within the rock layers of the Cedar Mountain Formation, dated to the early Cretaceous Period about 135 million years ago (the same time and place where… Read More ›
Gargoyleosaurus
When people think of “armored dinosaurs”, they generally think of two kinds of creature: the stegosaurs and the ankylosaurs. Both of these groups belong to the dinosaur sub-order Thyreophora, which means “armor-bearing” in ancient Greek. The dinosaur group Ankylosauria or… Read More ›
Zephyrosaurus
Zephyrosaurus was a small ornithopod dinosaur which lived in Montana during the middle Cretaceous Period. The first fossils of this animal were discovered by Charles R. Schaff, who worked at Harvard University’s Museum of Comparative Zoology. Schaff was prospecting for… Read More ›
Deinonychus: The Dinosaur that Changed the World
The skull of Deinonychus. This is the very first thing that appears on-screen in the first episode of the 1992 PBS documentary series The Dinosaurs! It’s a great series, by the way. You should watch it. Right now. Seriously. Get… Read More ›
Microvenator
In North America, dinosaur fossils are found in profusion in rocks dated to the late Triassic, late Jurassic, and late Cretaceous Periods. However, much of the rest of the Mesozoic Era’s time scale contains much sparser remains. The middle part… Read More ›
The Mysterious North American Colony of “New Belgium”
Most people who went to elementary school in the United States were given at least a cursory education in this country’s pre-colonial and colonial history. We learned about the so-called “Thirteen Colonies” which were owned by the British from the… 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 ›
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 ›