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.
Aetosaur
Aetosaur fossils have been found on all continents except Australia and Antarctica, giving them a nearly worldwide distribution during the Late Triassic. Many aetosaur remains have been found from the Chinle Group in the southwestern United States. Most fossils have been found from Arizona, New Mexico, and Texas. Some remains have also been found from Utah, particularly in Canyonlands National Park and Zion National Park. Aetosaurs are also known from the Newark Supergroup along the East Coast of the United States in states such as Connecticut and North Carolina. Two genera are known from Greenland: "Aetosaurus" and "Paratypothorax". They have been found from the Fleming Fjord Formation in Jameson Land. "Longosuchus" is the only aetosaur known from Africa, with scutes having been found from the late Carnian Timesgadiouine Formation in Morocco. During the Late Triassic, Morocco would have been in close proximity with the Newark Supergroup of North America in the supercontinent of Pangaea. It is also possible that "Desmatosuchus" was present in Africa, as fossils have been found from the Zarzaitine Series in Algeria that were referred to the genus.