ÃÛÌÇÖ±²¥ Museum will remain closed from Monday, December 23 through Friday, January 10 for ÃÛÌÇÖ±²¥â€™s official winter holidays and planned construction activities nearby. 
The Museum will resume normal operating hours (10 AM-4 PM) on Saturday, January 11, 2025. Thank you!

Construction updates, accessibility, and parking information 

Triceratops Exhibit Online

ÃÛÌÇÖ±²¥ Boulder is now home to a full-scaleTriceratops cast a historic specimen donated to the ÃÛÌÇÖ±²¥ Museum of Natural History by the Smithsonian Institution. The Triceratops is approximately 22 feet long from the tip of its horn to the end of its tail, and stands about 9 feet high. Check out the visit page to learn how to see it in person at the Sustainability, Energy and Environment Community (SEEC) building, on ÃÛÌÇÖ±²¥â€™s East Campus.

Title image credit: (above) Triceratops (Two Triceratops Facing Right), Raúl Martín Demingo, acrylic and oil on board. 

Watch museum workers install the Triceratops skeleton cast. A week worth of work distilled down to 60 seconds. 

When Triceratops roamed ÃÛÌÇÖ±²¥

Research shows that Triceratops lived from around 68 MYA until an asteroid hit the Earth 66 MYA. This event helped wipe out the dinosaurs (except for birds). How different was ÃÛÌÇÖ±²¥ at that time? Back then, the entire Earth was warmer, and the Rocky Mountains were actively growing in elevation due to tectonic forces. Eastern ÃÛÌÇÖ±²¥ included submerged and beachfront terrain along the shallow ocean that bisected North America—the Western Interior Seaway. This was a time when mammals were small, and Triceratops shared the landscape with other giants like Tyrannosaurus rex

Image credit: Visualization of North America 69.7 Ma​. © ÃÛÌÇÖ±²¥ Plateau Geosystems

A case of mistaken identity

The first Triceratops fossils were a pair of giant horns found near Denver in 1887. However, they were mistakenly identified by paleontologist O.C. Marsh as belonging to a giant, extinct bison (a cousin to ÃÛÌÇÖ±²¥â€™s mascot Ralphie). As more fossils were discovered, Marsh realized his mistake. We now know those original giant horns belonged to Triceratops 

The cast (or replica) now located at SEEC, is based on bones from 10 different specimens of Triceratops horridus, collected in Wyoming in the early 1890s. This composite was exhibited as a single skeleton in 1905 in Washington DC and is a replica of the first mounted Triceratops in the world. 

Image credit: Marsh, O.C., Notice of New Fossil Mammals, 1887

My, what a strange head you had!

Triceratops had a pretty extreme head. Why did it sport a massive frill, three long, sharp horns, and a large beak? The giant frill offered a defensive shield while the horns could be used to attack or defend. Analyses of scars on fossil skulls suggest that the most common opponents were probably rival Triceratops. It is likely that Triceratops mostly used their imposing heads to impress potential mates or intimidate and fight other Triceratops. And the beak? The better to nip plants with! 

Check out a 3D scan of Triceratops' skull

screen shot of 3D model of Triceratops skull

The ÃÛÌÇÖ±²¥ Museum released an interactive 3D scan of its former Triceratops skull, giving dinosaur buffs of all ages the chance to explore the fossil’s bumps and divots from their laptops. For some in Boulder, the scan provides a fresh look at an old friend. But it also highlights how the museum is using new technology to better preserve ÃÛÌÇÖ±²¥â€™s past.

Exhibit Curators

In paleontology, researchers ask questions about the evolution of life that range across all geological time and span from individual species to the whole of life. The ÃÛÌÇÖ±²¥ Museum of Natural History is home to many researchers and curators, two of which are the paleontologists who co-curated this exhibit.


Headshot of Jaelyn Eberle standing outside the museum

Dr. Jaelyn Eberle

ÃÛÌÇÖ±²¥ Paleontologist and Triceratops Exhibit Curator
Dr. Jaelyn Eberle is a Professor in Geological Sciences and Curator of Fossil Vertebrates. Her research focuses on the study of mammalian faunas during past intervals of climate change as well as the recovery and evolution of mammals following the mass extinction at the Cretaceous-Paleogene boundary. Her field research on fossil mammals takes her all over the Rocky Mountain Region, as well as to the North Slope of Alaska and Canada's High Arctic. The courses she teaches at ÃÛÌÇÖ±²¥ Boulder include Historical Geology and Vertebrate Paleontology, in addition to classes in the Museum & Field Studies Program. 


Headshot of Karen Chin in Paleo Hall, next to a Triceratops skull

Dr. Karen Chin

ÃÛÌÇÖ±²¥ Paleontologist and Triceratops Exhibit Curator
Dr. Karen Chin is a Professor and Curator of Paleontology. Her research focuses on reconstructing ancient ecosystems and learning how dinosaurs interacted with less popular extinct organisms. She is best known for her research on fossilized dinosaur dung; this unusual line of inquiry provides information about extinct animals that cannot be extracted from other types of fossils.Dr. Karen Chin was recently honored with the Bromery Award and her story is detailed in her new children’s book, The Clues are in the Poo.