Colorado dinosaur discovery – Triceratops

Triceratops skeleton
A skeleton of a Triceratops, known for its three horns and bony frill, is on display at Canada’s Royal Tyrrell Museum. The dinosaur was first discovered in west Denver in 1877. | Photo by entheos /


The first bones of the Triceratops, a pair of horn cores attached to the top of a skull, were discovered by George Coon as he excavated for brick clay along Dry Creek in west Denver in 1877.

The specimen was sent to paleontologist Othniel Marsh, who mistakenly thought that it came from a bison in the Pliocene era. Marsh changed his mind after other discoveries and identified the bones in 1889 as being from a Cretaceous period dinosaur that he called the Triceratops.

The bones were discovered in an area that today is part of Denver’s Lakewood / Dry Gulch Park, about halfway between Sheridan and Federal boulevards.

The Triceratops is best known for the three horns that emerge from its enormous skull and the large, bony frill at the back of the skull.

Paleontologists have long debated the purpose of the horns and frill, with some seeing them as tools for battle or defense but others seeing them as a sexual display.

The typical Triceratops reached nearly 30 feet in length, 10 feet in height and 13 tons in weight. The skull represented almost a third of its length, with one horn growing out of its snout and the others above its eyes.