plesiosaur

Trinacromerum

Trinacromerum was a 12 foot long plesiosaur which lived within the Mowry Sea, the shallow sea that covered North America during the middle of the Cretaceous Period 95 million years ago. The holotype specimen was found in 1888 within the… Read More ›

Peloneustes

Peloneustes was a 13 foot long pliosaur which swam in the sea around England during the middle of the Jurassic Period 165 million years ago. The first specimen of this animal was found near the city of Peterborough, Cambridgeshire, England… Read More ›

Cryptoclidus

Cryptoclidus was a 15 foot long plesiosaur which inhabited the prehistoric Tethys Sea, which once covered much of Europe, during the middle of the Jurassic Period 165-160 million years ago. Fossils of Cryptoclidus have been found within southern England and… Read More ›

Pliosaurus

We all know that dinosaurs walked the earth in prehistoric times, and many of us are also aware that pterosaurs flew across the skies and fearsome marine reptiles swam in the oceans. Some of these marine reptiles (which weren’t dinosaurs,… Read More ›

Hastanectes

Hastanectes valdensis, whose name means “the Hastings swimmer from the Weald”, was a prehistoric marine reptile which swam the seas around Europe during the early Cretaceous Period approximately 140 to 135 million years ago. The first fossils of this creature… Read More ›

Leptocleidus

Leptocleidus was a genus of plesiosaur which lived in the oceans during the early Cretaceous Period about 135 to 125 million years ago. It measured just 10 feet long, which is quite small for a plesiosaur. Three species of Leptocleidus… Read More ›

Pantosaurus

Hello everyone. Several years ago, I wrote a short article for Prehistoric Times magazine about the Sundance Sea. This was a shallow saltwater sea which covered much of central North America during the middle to late Jurassic Period. One of… Read More ›

Baptanodon

This is Baptanodon, an ichthyosaur which lived during the late Jurassic Period about 160-155 million years ago. During this time, the central part of North America was covered with a body of saltwater known as the Sundance Sea, and Baptanodon… Read More ›