Ceratopsian Dinosaur Bone | Montana

Specimen approx. size: 4" x 3.5" x 3"

Triceratops - The most common dinosaur encountered in the Late Cretaceous Hell Creek and Lance Formation is Triceratops. This large ceratopsian reached a length of over 30 feet long and weighed up to 10 tons. It was built like a bull or rhino and had a battering ram for a skull. Like the name implies it had three horns on its face… two large (3-4 feet long at maturity) horns on its brow and one shorter one on its nose. It also had a bony frill that covered the back of its neck that may have helped protect it from attack or make it look larger to frighten its enemies. This frill may have been brightly colored or displayed a unique pattern which helped it attract mates, locate members within the herd or help scare off would be challengers. These dinosaurs had a vice like bite and powerful jaws designed for chewing on very tough vegetation. Based on a handful of bone beds where many individuals have been found (common in other ceratopsians, but rare in Triceratops), they most likely traveled in large herds in the more upland and open regions of the Hell Creek ecosystem. As of 2017, at least 300 partial skeletons and skulls have been found since its discovery in the late 1800's. They are known from at least two species: T. horridus which had a shorter more compact skull and lower, nose horn, and T. prorsus, which had a longer skull and a very large forward projecting nose horn.

The Hell Creek Formation is an intensely-studied division of Upper Cretaceous to lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana.

The Hell Creek Formation occurs in Montana and portions of North Dakota, South Dakota, and Wyoming.

Strata in Hell Creek a series of fresh and brackish-water clays, mudstones, and sandstones deposited during the Maastrichtian, the last part of the Cretaceous period, by fluvial activity in fluctuating river channels and deltas and very occasional peaty swamp deposits along the low-lying eastern continental margin fronting the late Cretaceous Western Interior Seaway. The climate was mild, and the presence of crocodilians suggests a sub-tropical climate, with no prolonged annual cold. The famous iridium-enriched K–T boundary, which separates the Cretaceous from the Cenozoic, occurs as a discontinuous but distinct thin marker bedding within the Formation, near its uppermost strata.