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.
Amphitherium
The first jaws of mammals from the Mesozoic - including "Amphitherium" - were found in the Stonesfield Slate, part of the Forest Marble Formation at Kirtlington Quarry in England . These were bought by a student of William Buckland's. Although he thought the jaws were mammalian, he asked the great anatomist Georges Cuvier for his opinion. He misidentified them as being from a marsupial mammal, "Didelphis". Later they were identified as being a new genus, and named "Amphitherium". It was first mentioned in the scientific literature alongside "Megalosaurus", by the famous British paleontologist Reverend William Buckland. It came from the Stonesfield Slate of Oxfordshire, England, and Buckland described it in 1824 as ""not less extraordinary"" than the dinosaur, but it was the larger fossil reptile that captured public imagination.