Thalassomedon, meaning “lord of the sea”, was a 38 foot long elasmosaurid plesiosaur which lived within the Mowry Sea, the shallow sea that covered North America during the middle of the Cretaceous Period 97-95 million years ago. In March 1939,… Read More ›
Edgarosaurus was a 12 foot long short-necked plesiosaur which lived within the Mowry Sea during the middle Cretaceous Period 105-100 million years ago. In 1993, a well-preserved fossil specimen consisting of the skull, neck, and one front flipper (collection ID… Read More ›
Brachauchenius was a 15 foot long pliosaur which lived in the shallow sea that once covered the middle of North America during the middle Cretaceous Period 100-90 million years ago. Fossils of this animal were first found by Charles H…. Read More ›
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 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 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 ›
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 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 ›
NOTE: This post was originally published on May 13, 2022. It was updated and re-uploaded on April 14, 2026. Leptocleidus was a genus of plesiosaur which lived in the oceans during the early Cretaceous Period about 135 to 125 million years… Read More ›
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 ›
DINOSAURS AND BARBARIANS 