Sunday, October 29, 2023

Medusaceratops: Beast of the Week

 Medusaceratops lokii was a plant-eating dinosaur that lived in what is now Montana, USA, during the Late Cretaceous period, between 78 and 77 million years ago.  Medusaceratops measured about twenty feet long from beak to tail and was a member of the ceratopsian family of dinosaurs, most known for their horns, beaks, and frills. The genus name, Medusaceratops, translates to "Medusa Horn Face" in reference to the horns over the eyes and around the frill of this dinosaur, which curved downward, and were almost serpentine in shape.  This reminded paleontologists of the mythical creature called a gorgon, the most famous of which was named Medusa, who had snakes for hair and could turn people to stone if they looked at her.  The species namelokii, is in reference to Loki, the Norse god of trickery.  This is because the bones of Medusaceratops were believed to have belonged to other, already known ceratopsian dinosaurs for years, and in a sense, tricked paleontologists into thinking it was a different taxa before finally being recognized in 2010.

Medusaceratops life reconstruction by Christopher DiPiazza.

So why did Medusaceratops have those horns, anyway?  Unlike the horns of some other ceratopsians, which face up our outwards, this dinosaur's horns point downwards.  Unless it was fighting the monsters from Tremors, I doubt they would have been much good as weapons against predators.  Part of me still thinks that the horns, despite this, still could have deterred a predator from hurting vital areas on Medusaceratops' body, like the eyes or neck, simply by just being in the way.  This idea doesn't really hold up since there were so many different kinds of ceratopsains, each with unique horn arrangements, however.  If they were purely for defense, we would more likely see ceratopsian horns converge to a defensive arrangement across the family.  The more likely answer to these horns is that they were display adaptations, meant to intimidate and/or impress members of the same species.  If a would-be predator happened to break at tooth or two on a horn in a failed attempt to hunt Medusaceratops then it was icing on the ceratopsian cake...which that predator would never get to taste.

Medusaceratops skeletal mount on display at the Wyoming Dinosaur Center.

Medusaceratops was originally thought to be the oldest known chasmosaurine ceratopsian dinosaur on the fossil record.  Chasmosaurine ceratopsians typically had longer horns over their eyes, and proportionally long frills.  Chasmosaurus, Triceratops, Mercuriceratops, Coahuilaceratops, and Vagaceratops are all examples of other chasmosaurines.  More recently found material and further inspection of its bones, however, reveal that Medusaceratops was actually a member of the centrosaurine group of ceratopsians, known for having proportionally shorter frills and taller snouts, like Styracosaurus, StellasaurusWendiceratops, and Nasutoceratops.  

That is all for this week!  As always feel free to comment below.

References

Kentaro Chiba; Michael J. Ryan; Federico Fanti; Mark A. Loewen; David C. Evans (2018). "New material and systematic re-evaluation of Medusaceratops lokii (Dinosauria, Ceratopsidae) from the Judith River Formation (Campanian, Montana)". Journal of Paleontology92 (2): 272–288.

Ryan, Michael J.; Russell, Anthony P., and Hartman, Scott. (2010). "A New Chasmosaurine Ceratopsid from the Judith River Formation, Montana", In: Michael J. Ryan, Brenda J. Chinnery-Allgeier, and David A. Eberth (eds), New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Indiana University Press, 656 pp.