The material comprising the type series was discovered in the late 19th century from the Phosphate-bearing beds of La Penthèive (Mammilatum Zone; lower Albian) at Louppy-le-Château in eastern France, which have also produced remains of plesiosaurs, ichthyosaurs, and crocodiles.
The skeleton was discovered in Gronau, North Rhine-Westphalia in 1912 by paleontologist Theodor Wegner (the namesake of the species), but it was originally identified as that of Brancasaurus brancai, a plesiosaur that had been named in 1910 from fossils in the same locality.
In 2006 his team uncovered an enormous short-necked plesiosaur, the Pliosaurus funkei, possibly the largest carnivore found to date.
There are now more than 1,000 people claiming to have witnessed the beast which is reported to measure around fifteen meters long with spikes on its back and appears similar to a Plesiosaur or Ichthyosaurus.
Large well-known fossils excavated from the Smoky Hill Chalk include marine reptiles such as plesiosaurs, large bony fish such as Xiphactinus, mosasaurs, flying reptiles or pterosaurs (namely Pteranodon), flightless marine birds such as Hesperornis, and turtles.
Later the anatomist Sir Everard Home in London dismissed the measurement, declaring it must have been around 36 feet, and deemed it to be a decayed basking shark (basking sharks can take on a 'pseudo plesiosaur' appearance during decomposition).
The natural history collection includes remains of a plesiosaur called Bathyspondylus found at Swindon in 1774.