MOSA
SAURS
Fossil Record
Mosasaurus remains have been found in marine deposits on all continents around the world, including Antarctica. These animals were quite numerous and widespread throughout the world! The first fossil found was in the Netherlands during the mid-1700s. This was fifty years before the discovery of dinosaurs and mosasaurus fossils were among the first recognized fossils of large animals. By 1850, mosasaur fossils had been found in marine deposits of the Cretaceous time period all around the world, including England, New Jersey, South Dakota and New Zealand.
Discovery
Mosasaurs may have lived together in groups for the protection of their young. In order to protect them from other hungry predators around, including 20 foot long sharks, giant predatory fish (Xiphactinus) and other species of mosasaurs.
The first ever skull of Mosasaurus was found in what is now known as Netherlands, in 1780. That was a really long time ago! Johann Leonard Hoffmann thought it was crocodile, but he was very wrong. Petrus Camper thought it was an ancient sperm whale, he was wrong too! After finding the second skull in 1822, William Daniel Conybeare named the creature Mosasaurus. This fossil was apart of French revolutionary history, where the French forces took them away from the Fortress of Maastricht in Netherlands, and then moved them to France. They didn’t know Mosasaurus was an aquatic creature until 1854 when Hermann Schlegel said its limbs were flippers, and NOT feet.
The discovery of the Mosasaurus was revolutionary! We were now able to categorize old fossils found before and compare it to the Mosasaurus to find its relatives. This was a key information in filling in gaps about the food chain, aquatic creatures, and the water conditions.
An example of a mosasaur in the rock record.
The Mosasaurus hoffmannii skull found near Maastricht around 1770.