Dinosaurs ruled the land during the Mesozoic Era, but crocodiles and their relatives unquestionably ruled the water. Prehistoric crocodiles are usually relegated to the background as supporting actors or extras in our imagined Mesozoic dramas, but the truth is that… Read More ›
Jurassic Period
Leedsichthys
Leedsichthys was a very large prehistoric saltwater fish which lived during the middle and late Jurassic Period, circa 165-150 million years ago. It was named in 1889 in honor of Alfred N. Leeds who found the first specimen. Leedsichthys belonged… Read More ›
Aegirosaurus
Aegirosaurus leptospondylus was a 6 foot long ichthyosaur which lived in the seas around Europe during the late Jurassic Period and early Cretaceous Period, roughly 147-135 million years ago. Aegirosaurus belonged to a family of ichthyosaurs called the ophthalmosaurids (Bardet… Read More ›
Dimorphodon
Dimorphodon was a species of pterosaur that lived during the early Jurassic Period about 195-190 million years ago. It measured over 3 feet long from its nose to the end of its long tail (which may or may not have… Read More ›
Diplurus
Diplurus was a 3 foot long freshwater coelacanth fish which lived in the northeastern United States during the late Triassic and early Jurassic Periods, approximately 220-190 million years ago. It is divided into three species: D. longicaudatus, D. newarki, and… Read More ›
Anchisaurus
Anchisaurus was a prosauropod dinosaur whose fossils have been found in America’s northeastern states of Massachusetts and Connecticut within rocks dated to the beginning of the Jurassic Period, about 200-190 million years ago. Anchisaurus is one of the more well-known… Read More ›
Lissodus
Lissodus was a prehistoric shark which lived from the early Triassic to the middle Cretaceous Period, about 250 to 110 million years ago, give or take. Named in 1835, it was a member of a group of sharks called the… 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 ›
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 ›