Size and Weight:
Thanks to the discovery of numerous intact fossils, Rhomaleosaurus is one of the best-known pliosaurs of the early Jurassic period. In fact, this is one of those select marine reptiles (like the poster genus for the mosasaurs that succeeded the plesiosaurs and pliosaurs, Mosasaurus) that was dug up before its time: a complete Rhomaleosaurus skeleton was found by miners in Yorkshire, England in 1848, and must have given them quite a scare.
With its large head, sharp teeth and powerfully muscled body, the 20-foot-long Rhomaleosaurus was one of the most dangerous predators of its day, feeding on fish, squids, and smaller marine reptiles that crossed its path. This pliosaur also seems to have possessed an impressive sense of smell, picking up the scent of nearby prey as it funneled water through its nostrils.