About Styracosaurus
| Scientific Name (Genus) | Styracosaurus |
| Meaning of Name |
Spiked lizard
styrako (spike) [Greek] - saurus (lizard) [Greek] |
| Classification | Ornithischia, Marginocephalia (Ceratopsidae, Centrosaurinae) |
| Total Length | Approx. 5.2 - 5.5 m |
| Weight | Approx. 2.7 - 3.0 t |
| Diet | Herbivorous |
| Period | Late Cretaceous (Campanian: approx. 76.5 to 74.4 million years ago) |
| Habitat | Western North America |
| Year of Paper Publication | 1913 (Lawrence M. Lambe) |
Characteristics of Styracosaurus: A Giant Head and Distinctive Horns
Styracosaurus is a large quadrupedal dinosaur estimated to be approximately 5.2 to 5.5 meters in total length and 2.7 to 3.0 tons in weight. Its most prominent feature is its huge head, which accounts for about one-third of its total length (approximately 1.5 to 2.0 meters).
On its nose grew a single tall, upright horn about 50 to 60 cm long. Traces of thick blood vessels remain on the surface of the horn fossil, indicating that in life it was covered by a keratinous sheath (the same material as human nails and hair), so the actual horn is thought to have been even longer and larger than seen in the fossil. The horns over its eyes (supraorbital horns) were vestigial, like those of its closely related dinosaurs, and in adults they were reduced to small, low, rounded bumps.
The frill spreading behind its head had long spikes radiating backwards, making it one of the flashiest-looking ceratopsians. To prevent it from becoming too heavy, the frill bones had large openings (parietal fenestrae) to reduce weight.
Ceratopsians (Ceratopsidae) are broadly divided into two groups. The "Centrosaurinae" like Styracosaurus, which have a well-developed nasal horn and short horns over the eyes, and the "Chasmosaurinae" like Triceratops, which have long, well-developed horns over the eyes.
Charging Power Comparable to a Rhino, and a Picky Diet
Footprint fossils and studies using 3D computer models have revealed the athletic abilities of Styracosaurus. When moving its front legs, it walked with its elbows slightly pointing outwards, rather than completely straight. By combining this unique joint movement with the power of its hind legs, it is believed to have been able to reach a maximum running speed faster than modern elephants, exerting charging power comparable to a rhinoceros.
Its feeding method was also characteristic. The snout (beak) of Styracosaurus was narrow, and instead of eating plants at random, it seems to have been a "selective herbivore" that dexterously plucked only the highly nutritious parts from ferns and cycads.
At the back of its mouth was a "dental battery" consisting of sturdy teeth packed tightly together without gaps, specialized for chopping up plants like scissor blades, allowing it to efficiently digest even tough plant fibers.
The Mystery of "Rubeosaurus": A Fossil That Shocked Dinosaur Research
In the past, fossils with the characteristic of frill spikes curving forwards were discovered and classified as a different dinosaur called "Rubeosaurus". In addition, slightly different numbers or directions of frill spikes have led to the naming of several "new species" or "new genera" over the years.
However, a Styracosaurus skull fossil nicknamed "Hannah," published in 2020, delivered a major shock to dinosaur research. This fossil showed that even in the same single dinosaur, the number and shape of the spikes on the right and left sides of the frill were completely different (extreme asymmetry).
The discovery of "Hannah" revealed that "there is much greater individual variation in the shape and direction of frill spikes than we previously thought." It suggested that the shape and direction of spikes are diverse among individuals even within the same species, and can even be asymmetrical on the left and right sides of a single individual. Therefore, the prevailing view now is that the dinosaur once called "Rubeosaurus" was actually "within the range of individual variation of Styracosaurus" or "perhaps a transitional form during the evolution of Styracosaurus over time."
A Sudden Tragedy That Struck a Giant Herd
The fact that Styracosaurus lived in massive herds is clear from a huge "bonebed" discovered in Dinosaur Provincial Park, Alberta, Canada.
From this bonebed, fossils of hundreds of Styracosaurus, from juveniles to adults, were found together. This area was a coastal plain at the time, and was frequently subject to sudden storm surges and massive river floods caused by huge tropical cyclones (equivalent to modern hurricanes).
It is believed that these dinosaurs, moving in a giant herd, lost their escape routes due to this sudden rise in water and drowned instantly together. This tragic fossil record shows that they formed massive herds with mixed age groups.
A geological layer where fossils of a specific type of animal are found densely packed in one place in large quantities. It is an important clue for understanding their herd lifestyle and the nature of large-scale natural disasters that occurred in the past.
Scarred Warriors: Fierce Daily Life Told by Fossils
It is known that their large, flashy frills and horns were used not only to identify peers or appeal to the opposite sex, but also as weapons and armor in fierce battles.
Numerous scars (paleopathologies) indicating frequent, violent clashes have been found in the fossils of ceratopsians, including Styracosaurus. Examples include frills with holes pierced by a rival's horn, and bones showing signs of healing after being broken. In some cases, fossils have been found showing traces of severe infections (chronic osteomyelitis) caused by deep wounds, with pus accumulated even deep inside the bones.
Nevertheless, thick new bone formed around the wounds, showing attempts to heal, indicating that they possessed a resilient vitality to survive even with fatal injuries or illnesses.
The study of bone fractures and traces of disease left in fossils. It provides crucial clues for realistically deciphering their ecology, such as what kinds of injuries and diseases dinosaurs suffered from and how long they survived.
First Paper Description
A new genus and species from the Belly River Formation of Alberta. Ottawa Naturalist
by Lawrence M. Lambe. 1913.
This ceratopsian, discovered in Alberta, Canada, was named "Styracosaurus" in 1913 by paleontologist Lawrence Lambe.
Later, in 1935, a full-scale re-excavation was conducted by a survey team, unearthing many skeletal fossils including the lower jaw, which allowed its full-body appearance to be understood in detail.
Styracosaurus Stamp and Fossil Gallery
