Trinacromerum was a plesiosaur, a type of marine reptile. It was not a dinosaur, though it coexisted with many dinosaurs. Trinacromerum lived during the Late Cretaceous. The first Trinacromerum fossil was discovered in 1888.

Quick facts about Trinacromerum:

  • Existed from 155.7 million years ago to 66 million years ago
  • Lived in a marine environment
  • Was a carnivore
  • Reproduced by live birth
  • 77 different specimens have been found by paleontologists

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

Trinacromerum was described by the following scientific paper(s):
  • R. L. Nace. 1939. A new ichthyosaur from the Upper Cretaceous Mowry Formation of Wyoming. American Journal of Science 237(9):673-686
  • D. Bardack. 1968. Fossil vertebrates from the marine Cretaceous of Manitoba. Canadian Journal of Earth Sciences 5:145-153
  • J. T. Thurmond. 1968. A new polycotylid plesiosaur from the Lake Waco Formation (Cenomanian) of Texas. Journal of Paleontology 42(5):1289-1296