Ceratopsian

“These dinosaurs could be as small as a dog or bigger than a car.”

Ceratopsian Facts

• The herbivorous dinosaurs had beaks like parrots and hips like birds.
• Their scales did not overlap like modern snake scales do.
• Some of the first ceratopsian bones discovered in the American west were mistaken for bison.
• Some of them had frills covering their necks for protection, or to radiate excess heat.
• They are among the last types of dinosaurs that went extinct over 65 million years ago.

Ceratopsian Scientific Name

In Greek, “ceratopsian” means “horned face.” Although not all of them had horns on their faces, their most famous representative, the Triceratops, did. Ceratopsian is a name not just for one species, but for a whole group of herbivorous dinosaurs that had beaks and hips like birds and a frill on the back of their skull.

Paleontologists have begun moving away from ranked taxonomies of dinosaurs, but a recent and respected text, Michael Benton’s Vertebrate Paleontology, ranks all dinosaurs in this way:

Series Amniota; Class Sauropsida; Subclass Diapsida; Infraclass Archosauromorpha; Division Archosauria; Subdivision Avemetatarsalia; Infradivision Ornithodira; Superorder Dinosauria. Dinosauria is divided into two orders: Saurischia and Ornithischia.

Ceratopsia are classified as: Order Ornithischia; Suborder Cerapoda; Infraorder Ceratopsia. Within Ceratopsia are three families: Family Psittacosauridae; Family Protoceratopsidae; Family Ceratopsidae.

Description & Size

“Ceratopsian” is actually the name for a group of dinosaurs made up of several different species of different size and characteristics. Some of the earliest members of this group were small dinosaurs that walked on two legs and had no horns; the latest ones became extremely large with dangerous horns on their face for defense. They could range from 3 feet long and weighing 50 pounds, to 30 feet long and 20,000 pounds. By comparison, a modern Rhinoceros can grow up to 13 feet long and weigh up to 2,100 pounds.

What makes a dinosaur a ceratopsian? All of them have parrot-like beaks, frills on the back of their skulls, and hips with bird-like structure. Interestingly, the bird-like structures in the ceratopsian and other dinosaur species leads researchers to believe that some dinosaurs evolved into birds. So instead of saying the ceratopsian had bird-like features, maybe we should say birds have dinosaur-like features!

Dinosaurs classified as ceratopsian were all herbivores, using their beaks to snip off tree branches to grind with their powerful teeth. Researchers aren’t entirely sure about the purpose of these dinosaur’s skull frills, but speculate they were used to defend the animal’s neck from attackers, to radiate excess heat, or as a place of attachment for strong jaw muscles. These frills look different in different species, with some being more elaborate than others and some made of solid bone while others had hollow openings.

Ceratopsian Evolution and History

The earliest fossils of this species have been found in Asia, so researchers think that is where the species originated, then crossed the Bering Strait to Alaska and the rest of North America around the middle of the Cretaceous Period. Triceratops remains are the most common large dinosaur fossils found in the latest Cretaceous sedimentary layer in the western United States; in some places accounting for 4 out of 5 large fossil discoveries, so they may have been the dominant herbivore in that habitat.

The earliest ceratopsian dinosaurs, the psittacosauridae, walked on two legs and had a beak and a small frill on the back of their skull but did not have horns. A second group, the protoceratopsidae, walked on four legs, were larger and had a larger frill, but also did not have horns. The last group, the ceratopsidae, had large frills, horns on the nose and above the eyes. Some members of this group had longer horns above the eyes and a shorter one on the nose; others the reverse. Some of them had frills that were short and made of solid bone; others were larger and were open in the center.

Diet – What Did a Ceratopsian Eat?

Because ceratopsian fossils show that they had a sharp “beak” and heavy rows of grinding teeth, researchers believe they were herbivores that fed on tough woody vegetation. At the time they lived, this would have included palms, cycads, and angiosperms.

Habitat – When and Where It Lived

Ceratopsian dinosaurs lived during the entire Cretaceous Period, from 145.5 million years ago to 66 million years ago. Ceratopsian fossils have been discovered in North America, Europe, and Asia. Many of these animals would have lived in forested areas that had plenty of vegetation for herds of them to feed on.

Threats And Predators

During the 79 million years of the Cretaceous Period, ceratopsian dinosaurs evolved into different species, from dog-sized to larger than a car. Their predators also changed throughout this period and included such species as Acrocanthosaurus atokensis, Siats meekerorum, Lythronax argestes, and Tyrannosaurus rex. Ceratopsian eggs, babies, and smaller species of this group would have been vulnerable to carnivores of a range of sizes, not just apex predators like T-Rex.

Although ceratopsian dinosaurs were herbivores, they had powerful defenses. Some species, including triceratops, had horns that could be deadly. All species had sharp beaks, which in the larger animals would have been strong enough to break bones. They may also have used a strategy of staying together in a herd and grouping up with their horns facing out, as some modern species of horned herd animals do. One reason researchers believe this was a herd creature is the discovery of hundreds of fossils of the same species located close to one another.

Discoveries and Fossils – Where were They Found?

Ceratopsian fossils were first discovered in 1855 in Montana during a government land survey. Other discoveries of the species were made later in the 19th century in Montana and Wyoming. Throughout the 19^th and 20^th centuries, paleontologists uncovered other examples in Germany, Sweden, Slovakia, Russia, Uzbekistan, Mongolia, China, South Korea, and Japan. The earliest ceratopsian species are found in Asia, while later developments of it are prevalent in North America. Some recent fossil discoveries in South America may also prove to be part of this species.

Extinction – When Did They Die Out?

The last ceratopsian was Triceratops prorsus. It went extinct during the Cretaceous-Paleogene extinction event, 66 million years ago. This is when 75% of all plant and animal species went extinct. The prevailing theory is that it was due to an asteroid impact. The impact is in what is today the Yucatan Peninsula of Mexico that had global effects on the climate. Scientists have discovered multiple lines of geologic evidence to support this theory. Including a fine layer of iridium, an element expected as a byproduct of asteroid impact. It has been located all over the world in the rock stratum that marks the end of the Cretaceous.

Similar Animals to a Ceratopsian

• Edaphosaurus – an older species than the ceratopsian that lived 318-271 million years ago. They were about 11.5 feet long and had a large sail on their backs that helped regulate heat.
• Dilophosaurus – these dinosaurs were carnivores of the Jurassic period. They had crests on their heads and inflatable air sacs for display. They were depicted as venomous “spitting” dinosaurs in the movie Jurassic Park.
• Ankylosaurus – a heavily-armored dinosaur with a defensive club on its tail. They could grow up to 33 feet long and weigh up to 9 tons.

Related Animals

• Triceratops
• Stegosaurus
• Styracosaurus

1. Wikipedia, Available here: https://en.wikipedia.org/wiki/Ceratopsia
2. UCMP.Berkeley.edu, Available here: https://ucmp.berkeley.edu/diapsids/ornithischia/ceratopsia.html
3. Britannica, Available here: https://www.britannica.com/animal/ceratopsian