This holiday season, Carnegie Museum of Natural History’s blog has a special gift for you: Mesozoic Monthly, a new series of spotlights on the weird and wonderful organisms that lived during the time of the dinosaurs! The first lucky honorary of this series is Einiosaurus procurvicornis (pronounced EYE-nee-oh-SAWR-uss PRO-kurv-ih-KORN-iss), a ceratopsian, or horned dinosaur, with a festive, candy cane-shaped nasal horn.
Ceratopsian dinosaurs are known mostly for their strange facial adornments, and understandably so! Einiosaurus belongs to a group of ceratopsians called centrosaurines (a group that also includes dinosaurs such as Styracosaurus and Centrosaurus). Centrosaurines are distinguished by their elaborate nasal horns and spiky frills. The famous ceratopsian Triceratops is not a centrosaurine; instead, it is a chasmosaurine, a group known for their long eyebrow horns and relatively plain frills. Instead of noticeable horns above its eyes like chasmosaurines, Einiosaurus had several small nubs that give the appearance of rough, bumpy ‘eyebrows.’ Of course, however, Einiosaurus is best known for the iconic and bizarre forward-curving horn on its nose.
There are several hypotheses about why ceratopsians have such horny faces. Many people think their horns were for combat, such as defense from predators and intraspecific battles for territory or mating rights. Although everyone gets excited over cool dino brawls, not every paleontologist is on board with the idea that the horns were used for fighting. In the case of Einiosaurus, it is certainly hard to imagine jousting with those curved horns; it would take a very exaggerated downward strike to effectively use them as weapons. Whether the horns were for combat or not, we can assume that they were practical tools for species recognition and sexual selection. Being able to grow a large and impressive horn shows that you have good genes, even if you aren’t using it to fight off your competition.
Indeed, when it came to finding mates, individual Einiosaurus may have had plenty of competition: paleontologists have found several skeletons of Einiosaurus preserved together, leading us to believe that they lived in groups, like bison, aka American buffalo. In fact, the name Einiosaurus procurvicornis means “buffalo lizard with forward-curving horn.” “Eini” means “buffalo” in the Blackfeet language, which is a reference to the fact that the original specimens of Einiosaurus were discovered on Blackfeet Nation land in Montana. The rock formation in which they were found has also yielded many other dinosaur fossils, giving us a good understanding of the ecological community that Einiosaurus inhabited. Familiar dinosaurs like Maiasaura and Gorgosaurus along with less familiar ones such as Scolosaurus, Bambiraptor, or Prosaurolophus shared a habitat that experienced annual arid seasons and monsoon rains. Despite these wild changes in weather, the temperature would have been relatively stable and warm year-round. So unfortunately, our candy-cane-adorned dinosaur probably never experienced snow, but it’s nice to think about!
Lindsay Kastroll is a volunteer and paleontology student working in the Section of Vertebrate Paleontology at Carnegie Museum of Natural History. Museum staff, volunteers, and interns are encouraged to blog about their unique experiences and knowledge gained from working at the museum.