The fossilized bones of a huge marine reptile, later identified as a Mosasaur, were discovered in a quarry near Maastricht in the Netherlands. This was one of the first large vertebrate fossils to be scientifically recognized, and its discovery sparked considerable scientific and public interest. It was not until 1795 that Georges Cuvier identified the bones as belonging to an extinct reptile, making it a key find in the history of paleontology.

The discovery of the Mosasaur, the 'lizard of the Meuse,' was a pivotal moment in the recognition of extinction. The huge, alien reptile, clearly not a living creature, provided dramatic evidence that the world had once been inhabited by creatures that no longer existed. This discovery, and Cuvier's subsequent analysis, was central to the development of the concept of extinction, a theme that would deeply influence the Romantic poets and their fascination with lost worlds and the sublime power of nature.