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Unveil Captivating Facts About The Prehistoric Beast: Chasmosaurus

Unveil Captivating Facts About The Prehistoric Beast: Chasmosaurus

Chasmosaurus was one of the prehistoric reptiles that roamed North America's plains. It was one of the last big dinosaurs to have evolved before the extinction of these magnificent creatures. The genus Chasmosaurus translates to Chasm Lizard, Dinosaur in reference to the two large holes called fenestrae in its frills. Chasmosaurus fossils belong to the ceratopsian dinosaur that lived between 76.5 and 75.5 million years ago during the Late Cretaceous period. The distinguishing fenestrae are present in almost all ceratopsians but are particularly large in Chasmosaurus.

It is referred to as a prehistoric beast because it measured 16-26 feet long from the snout to the tail, weighed 3.5 tons or more, and would have eaten plants when alive. These big mammals possessed small tails. The legs were four in number- short and consisting of five toes on each foot.

 Chasmosaurus fossil tooth

Quick Facts 

  • The most famous dinosaur, Tyrannosaurus Rex (T-Rex), was contemporary to Chasmosaurus and likely fed on them.
  • Nearly all specimens of these dinosaur fossils were collected from either the Dinosaur Park Formation or the Dinosaur Provincial Park of Alberta.
  • The fossils of the species C. Russell come from the lower beds of the formation, while C.belli comes from the middle and upper beds of the formation.
  • It existed from the Campanian age and lived in a terrestrial habitat.
  • It reproduced by laying eggs and had a body mass of about 1658.7 kg.
  • Till now, 18 different specimens have been found by paleontologists.


History And Discovery

The well-known paleontologist Lawrence Morris Lambe discovered the first fossilized remains of Chasmosaurus from areas around Alberta in Canada in 1898. The fossil remains were a parietal bone that was part of the frill of the neck. Again, in 1913 he discovered other fossils of the different species of this genus. Initially, he decided to name all his findings Protorosaurus, but eventually, in 1914, he named them Chasmosaurus, which means 'opening lizard' in the context of the big openings in its frills.

 Chasmosaurus fossil tooth

Since that date, more remains, skulls and evidence have been found that have been referred to as Chasmosaurus fossils, and several additional species have been known within these species. The most recently discovered species was Chasmososurus irvinensis in 2001 and stemmed from the upper beds of the Dinosaur Park Formation.


Physical Or Bodily Features

The Chasmosaurus looked more like the modern-day Rhinoceros except for the large dinosaur bones and the frills, extra horns, and a toothless beak. Moreover, it supposedly had rough four-layered skin. The extra large frill originated from the back part of the skull. The body of the Chasmosaurus was structurally shaped like a barrel.

 Chasmosaurus fossil tooth with tendon

Most species of the Chasmosaurus genus had three horns on its face- two relatively narrow ones on their brows and one robust one on the snout. The entire structure of the frill is significantly large and somewhat rectangular. According to scientists, there are the major species of Chasmosaurus. The older one is called Chasmosaurus russelli, which has long horns on the brows, and the younger one is Chasmosaurus belli which has smaller brow horns and a shallow V shape on the center of the frill. The primary difference between the two species mainly pertains to the horn and the frill shape.

The frill of the Chasmosaurus is very elongated and broader at the rear than at the front. Its sides are adorned with six to nine smaller skin ossifications or osteoderms attached to the squamosal bone. The corner of the frill features two large osteoderms on the parietal bone. The parietal bones of the frills are pierced with very large openings, after which the genus has been named.

It had claws on its hoofs, and this dinosaur's tail was fairly short and quite pointed. The jaws of the species looked like a beak and worked better at grasping or plucking rather than biting.



The exact functionality of the frill is still a mystery. However, there are certain speculations made by scientists and paleontologists about the functioning of the frill.

  • At first, scientists presumed that it was used for defenses against predators, but its lightweight and big holes put questions on these assumptions.
  • The second assumption is that they help the species to thermoregulate much like the modern ears do for most mammals by pumping blood through it and cooling it off.
  • The third idea is that these were either for display or communication. These may have served as devices for communication between the animals of the same species, either for species recognition or for attracting mates.



Like most other species of the ceratopsians, Chasmosaurus was a horned and herbivore species and were probably herding animals moving in groups within their prevailing environment. However, this is just a hypothesis discovered by paleontologists established based on Chasmosaurus fossil evidence, such as the discovery of large deposits and beds of skeletons fragments or remains from a single site belonging to the same species.


The baby Chasmosaurus most likely hatched from large eggs that the adults carried to protect them from predators or enemies. When attacked by predators, they could even charge their enemies as a defense and could even run fast, much like the modern-day rhinos.



Scientists and paleontologists speculate that the Chasmosaurus was predominantly plant eaters and fed on cycads, palms, or several other plants found in prehistoric times.


Fossil Evidence Of Chasmosaurus

In the fossil evidence found of Chasmosaurus, there has been found skin impressions of the hip region show mosaic-like scales of varying sizes consisting of larger scales in the center surrounded by smaller ones forming patterns. Most scientists depict large ceratopsians such as Chasmosaurus with long quill-like structures growing from these structures.

Scientists discovered one of the beautifully preserved fossils of a Chasmosaurus baby a few years ago. It had the complete skeleton missing only the forelimb and measured five feet long from the beak to the tail. The frill and the legs were proportionally smaller than the babies of the other ceratopsians. The research team further estimated that the little dinosaur was only three years old when it died. The sediment bones in which the fossil has been preserved represent a watery environment. The lack of evidence of predation or scavenging suggests that the baby dinosaur probably died of some natural forces.

 Chasmosaurus fossil jaw bone

Add The Fossil Of This Magnificent Dinosaur To Your Collection!

If you are intrigued to learn and explore the origin and the extinction of different species, Fossil Age Minerals is just the right place for you. We offer a wide variety of fossil collections at an affordable price for you to preserve and learn about them. Contact us to add the Chasmosaurus fossil to your rare and invaluable collection.

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