Mosasaur
Mosasaurs (from Latin "Mosa" meaning the 'Meuse river', and Greek σαύρος "sauros" meaning 'lizard') are an extinct group of large marine reptiles containing 38 genera in total. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous. During the last 20 million years of the Cretaceous period (Turonian-Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators. They became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago.
Mary Anning
Anning searched for fossils in the area's Blue Lias cliffs, particularly during the winter months when landslides exposed new fossils that had to be collected quickly before they were lost to the sea. She nearly died in 1833 during a landslide that killed her dog, Tray. Her discoveries included the first ichthyosaur skeleton correctly identified; the first two more complete plesiosaur skeletons found; the first pterosaur skeleton located outside Germany; and important fish fossils. Her observations played a key role in the discovery that coprolites, known as bezoar stones at the time, were fossilised faeces. She also discovered that belemnite fossils contained fossilised ink sacs like those of modern cephalopods. When geologist Henry De la Beche painted "Duria Antiquior", the first widely circulated pictorial representation of a scene from prehistoric life derived from fossil reconstructions, he based it largely on fossils Anning had found, and sold prints of it for her benefit.