Mosasaurus is an extinct genus of large marine reptile that lived during the Late Cretaceous period, approximately 70-66 million years ago. The genus is known from fossil remains found in North America, Europe, and Asia.

A complete Mosasaurus skeleton would include a long, streamlined body with four flippers and a powerful tail for swimming, as well as a long, pointed snout and rows of sharp teeth for catching prey. The skeleton would also include a number of other distinctive features, such as elongated cervical vertebrae, which allowed Mosasaurus to move its head quickly and snatch prey, and a set of sturdy hindlimbs that may have been used to propel itself through the water.

While complete Mosasaurus skeletons are rare, a number of well-preserved specimens have been found over the years, including one at the Natural History Museum of Maastricht in the Netherlands, which is considered one of the best-preserved Mosasaurus skeletons in the world. This specimen measures approximately 16 meters (52 feet) in length and provides valuable insight into the anatomy and behavior of this fascinating prehistoric reptile.