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 ›

Paleontology
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 ›
Saurosuchus
Saurosuchus was a 20-foot pseudosuchian (a distant ancestor of crocodiles) which lived in Argentina during the middle Triassic Period about 230 million years ago. It was the largest carnivorous animal in its environment in terms of both length and weight,… Read More ›
Panphagia, the Oldest-Known Sauropodomorph Dinosaur
For decades, South America has been regarded by paleontologists as the place where dinosaurs originated. It is here that we have our clearest record of what the oldest dinosaurs looked like. Specifically, Brazil and Argentina hold the record for the… Read More ›
Ceratodus: The Iconic Lungfish of the Mesozoic Era
Ceratodus was a genus of prehistoric lungfish which existed on Earth for a surprisingly long time, from the middle of the Triassic Period approximately 227 million years ago to the beginning of the Eocene Epoch of the Tertiary Period about… Read More ›
Promastodonsaurus
This is Promastodonsaurus, literally meaning “before Mastodonsaurus”. Despite its saurian name, it was not a dinosaur, or even a reptile – it was actually a large amphibian. Fossils of Promastodonsaurus were found in Argentina within the rocks of the Ischigualasto… Read More ›