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.
Partridge Island (Nova Scotia)
Since 1970 when the American paleontologist Paul E. Olsen discovered a neck vertebra of a long-necked dinosaur known as a prosauropod near Parrsboro, the north shore of the Minas Basin has been recognized as an important source of fossils. In 1984, for example, amateur rock specialist Eldon George discovered the world's smallest dinosaur footprints at Wasson Bluff about 10 kilometres from Partridge Island. Then, in 1986, Olsen and two colleagues announced they had retrieved 100,000 fossilized bones including some belonging to the oldest dinosaurs ever found in Canada.