Thalassomedon was a plesiosaur, a type of marine reptile. It was not a dinosaur, though it coexisted with many dinosaurs. Thalassomedon lived during the Late Cretaceous. The first Thalassomedon fossil was discovered in 1943.

Quick facts about Thalassomedon:

  • Existed from 99.6 million years ago to Turonian Age
  • Lived in a marine environment
  • Was a carnivore
  • Reproduced by live birth
  • 2 different specimens have been found by paleontologists

All the Thalassomedon illustrations below were collected from the internet. Enjoy and explore:

Thalassomedon was described by the following scientific paper(s):
  • S. P. Welles. 1943. Elasmosaurid plesiosaurs with description of new material from California and Colorado. Memoirs of the University of California 13:125-254