Protoceratops (pro·to·cer·a·tops) (/ˌproʊtoʊˈsɛrətɒps/; from Greek proto-/πρωτο- "first", cerat-/κερατ- "horn" and -ops/-ωψ "face", meaning "First Horned Face") is a genus of sheep-sized (1.8 m long) herbivorous ceratopsian dinosaur, from the Upper Cretaceous Period (Campanian stage) of what is now Mongolia. It was a member of the Protoceratopsidae, a group of early horned dinosaurs. Unlike later ceratopsians, however, it was a much smaller creature that lacked well-developed horns and retained some primitive traits not seen in later genera.
Protoceratops had a large neck frill which was likely used as a display site to impress other members of the species. Other hypotheses about its function include protection of the neck and anchoring of jaw muscles, but the fragility of the frill and the poor leverage offered by possible attachment sites here makes these ideas implausible. Described by Walter W. Granger and W.K. Gregory in 1923, Protoceratops was initially believed to be an ancestor of the North American ceratopsians. Researchers currently distinguish two species of Protoceratops (P. andrewsi and P. hellenikorhinus), based in part by their respective sizes.
In the 1920s, Roy Chapman Andrews discovered fossilized eggs in Mongolia that were interpreted as belonging to this dinosaur, but which turned out to be those of Oviraptor.
Description[]

Size comparison of two Protoceratops species
Protoceratops is often depicted fighting packs of hungry Velociraptors. Protoceratops had a large bony skull with a bump on it snout, a sharp beak and a protective frill. Protoceratops lacks the horns that future ceratopsians have, like Triceratops, Protoceratops had a short, blunt nose horn. Protoceratops likely lived in small family groups. Protoceratops may have had a small tuft of feathers on its tail like Psittacosaurus.

Adult specimen of P. andrewsi.
Protoceratops was a quadrupedal dinosaur that was partially characterized by its distinctive neck frill at the back of its skull. The frill itself contained two large parietal fenestrae (holes in the frill), while its cheeks had large jugal bones. The exact size and shape of the neck frill varied by individual; some specimens had short, compact frills, while others had frills nearly half the length of the skull. The frill consists mostly of the parietal bone and partially of the squamosal. Some researchers, including Peter Dodson attribute the different sizes and shapes of these bones to sexual dimorphism, as well as the age of the specimen, at the time of death.
A large concentration of Protoceratops fossils originate in herds, and many life stages are represented through fossil specimens. The animal started as small hatchlings, with bulbous noses and blunt frills. Compared to adults, juveniles had considerably larger eyes, thinner bodies, and were overall smaller. Adult Protoceratops had wide frills, which may have been used to impress females, or to anchor thick jaw muscles. The frill contained two large parietal fenestrae, and defined jugals sprouted from the cheeks. Some individuals' frills were small and compact, while others measured half their skulls length, showing that the frills were distinct per every animal. The frill itself is mostly formed from parietal bone and the squamosal. Some researchers consider the frill to be sexual dimorphism, also depending on age. Protoceratops was a small dinosaur, having a disproportionally large head. A large beak was capable of a powerful bite, which was likely a defense as seen in the dueling dinosaurs fossil, of a Velociraptor caught in the death grip of Protoceratops' beak. The jaws were packed with teeth, which mulched vegetation for digestion. The entire skull has four fenestrae, the closest being the naris, which is much smaller than the nostrils of genera to come later. Each eye orbit is 50 millimeters in diameter, with the infratemporal fenestra hidden behind them. Out of all dinosaur fossils, Protoceratops is among the more abundant types[1].
Protoceratops was approximately 1.8 meters (5.9 ft) in length and 0.6 meters (2 ft) high at the shoulder. A fully grown adult would have weighed about 82.7 kilograms (182 lb). Smaller specimens are estimated at 23.7 kilograms (52 lb). The large numbers of specimens found in high concentration suggest that Protoceratops lived in herds. Restoration of P. andrewsi Protoceratops was a relatively small dinosaur with a proportionately large skull. Protoceratops appears to have had muscular jaws capable of a powerful bite. These jaws were packed with dozens of teeth, well suited for chewing tough vegetation. Based on other relatives, and a specimen that was found in a collapsed tunnel, protoceratops was likely a burrower, dwelling underground and digging holes to live in. The skull consisted of a massive frontal beak, and four pairs of fenestrae (skull openings). The foremost hole, the naris, was considerably smaller than the nostrils seen in later genera. Protoceratops had large orbits (the holes for its eyes), which measured around 50 millimeters in diameter. Behind the eye was a slightly smaller fenestra, known as the "infratemporal fenestra."
Discovery and species[]

Flaming Cliffs of Mongolia. This highly fossiliferous locality of the Gobi Desert yielded the first known remains of Protoceratops
Photographer James Blaine Shackelford discovered the first specimen of Protoceratops in the Gobi desert, (Gansu, Inner Mongolia), as part of a 1922 American expedition looking for human ancestors. No early human fossils were found, but the expedition, led by Roy Chapman Andrews, collected many specimens of the genus Protoceratops, along with fossil skeletons of theropods Velociraptor, Oviraptor, and ceratopsian Psittacosaurus.
Walter Granger and W. K. Gregory formally described the type species, P. andrewsi in 1923, the specific name in honor of Andrews. The fossils hail from the Djadochta Formation and date from the Campanian stage of the Upper Cretaceous (dating to between 75 and 71 million years ago). Researchers immediately noted the importance of the Protoceratops finds, and the genus was hailed as the "long-sought ancestor of Triceratops". The fossils were in an excellent state of preservation, with even the sclerotic rings (delicate ocular bones) preserved in some specimens. P. hellenikorhinus skull
In 1971, a fossil was found that captured a Velociraptor mongoliensis clutched around a Protoceratops andrewsi in Mongolia. It is believed that they died simultaneously, while fighting, when they were either surprised by a sand storm or buried when a sand dune collapsed on top of them.
In 1975, Polish paleontologists Teresa Maryanska and Halszka Osmólska described a second species of Protoceratops, also from the Campanian stage of Mongolia, which they named P. kozlowskii. However, the fossils consisted of incomplete juvenile remains, and are now considered synonymous with Bagaceratops rozhdestvenskyi.

Holotype skull of P. hellenikorhinus at the Inner Mongolia Museum
In 2001, a second valid species, P. hellenikorhinus, was named from the Bayan Mandahu Formation in Inner Mongolia, China and also dates from the Campanian stage of the Upper Cretaceous. It was notably larger than P. andrewsi, had a slightly different frill, and had more robust jugal horns. The arch of bone over its nostrils had two small nasal horns, and there were no teeth at the front of the snout.
In 2011, a specimen of Protoceratops first uncovered in 1965 was found to be preserved with its own footprint. It is the first example of a dinosaur to be preserved with footprints.
Paleobiology[]
Reproduction[]

Skeletal mount of Protoceratops with juveniles
The cast of the Protoceratops sp. egg at the Wrexham Museum, Wales
P. andrewsi hatchling at the American Museum of Natural History in New York City
In the 1920s, Roy Chapman Andrews discovered the first known fossilized dinosaur eggs, in the Gobi Desert of Mongolia. Each egg was about 8 inches long, and newborn hatchlings estimated to have been about a foot in length. Due to the proximity and abundance of Protoceratops, these eggs were believed at the time to belong to this genus.
The contemporary theropod Oviraptor was thought to consume Protoceratops eggs due to the discovery of an Oviraptor skeleton present at a nest. The skull was crushed, and it was speculated that the injury was received by a Protoceratops mother defending her nest from the predator. However, in 1993 Norrell et al. discovered an embryo inside a supposed Protoceratops egg. This embryo, upon close examination, turned out be an Oviraptor; the original find represented Oviraptor brooding behavior rather than a failed attempt at oophagy.
The oogenus Protoceratopsidovum (meaning "Protoceratops egg") was also originally misidentified as belonging to Protoceratops; it is now known to be the eggs of a derived theropod. P. andrewsi growth series In 2011, a nest of 15 young Protoceratops andrewsi was discovered in Mongolia. Stated as being the first Protoceratops nest discovered to date, the discovery suggests that Protoceratops parents might have cared for their young at nests during at least the early stages of childhood. As Protoceratops is a relatively basal member of the ceratopsians, the finding also suggests that other ceratopsians provided care for their young as well. Studies of lines of growth (i.e. lines of von Ebner) of the teeth in embryonic P. andrewsi suggests plesiomorphically long incubation times, with a minimum incubation time of 83.16 days for P. andrewsi.
Daily activity patterns[]

Skull of P. andrewsi AMNH 6466, preserving sclerotic ring
The large eyes of Protoceratops has been suggested as evidence for a nocturnal lifestyle. However, subsequent comparisons between the scleral rings of Protoceratops and modern birds and reptiles have indicated a more cathemeral lifestyle, being active throughout the day during short intervals. This suggests that the fight between Protoceratops and the primarily nocturnal Velociraptor indicated by the fighting specimens may have occurred at twilight or under low-light conditions.
Integument[]

AMNH 6418 before preparation.
Specimen AMNH 6418 is a Protoceratops specimen found curled in a ball with its foot over the animals face. This specimen was brought into the spotlight on Twitter, where users contemplated whether the image shows skin impressions preserved over the fossils face, or if the material is matrix. The individual itself is a young-adult that preserves the skull, a partial torso, tail and incomplete legs. The describers were aware of the unique mass on the face, but brushed over the feature in a short paragraph, dismissing the plausibility of skin impressions. They describe the surface as thin, hard and wrinkled and as covering the frill, jaw and face and having a very skin-like appearance. They note it can not be determined 100% as skin, although the decomposing skin may have influenced the matrix. Decomposition may have caused the sediment to harden and indurate. Since then, most of the material has been prepared from the specimen, as paleontologists at that time disregarded anything but bone[2]. In 2022, patches of the original soft tissue were confirmed to have not been fully destroyed during preparation[3].
Classification[]

Early interpretation of the evolutionary relationships of Protoceratops with ceratopsids upon its discovery; a notion now obsolete
Protoceratops was the first named protoceratopsian and hence gives its name to the family Protoceratopsidae, a group of herbivorous dinosaurs more derived than psittacosaurids, but less derived than ceratopsids. The group is characterized by their similarities to the Ceratopsidae but with more cursorial limb proportions, generally smaller frills, and lack of large horns.
In 1998, Paul Sereno defined Protoceratopsidae as the branch-based clade including "all coronosaurs closer to Protoceratops than to Triceratops." Some studies placed Bagaceratops, Breviceratops, Graciliceratops, Magnirostris, Platyceratops, and Serendipaceratops within Protoceratopsidae, but in 2006, Makovicky and Norell published a new phylogeny which removed several genera from Protoceratopsidae; several other phylogenies also exist. Bainoceratops may be synonymous with Protoceratops.

Protoceratops (A, D, E) compared to other ceratopsians

Size of Protoceratops (1, 3) compared with other protoceratopsids
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Cultural significance[]
Origin of griffin myths[]

A traditional depiction of the griffin
Folklorist and historian of science Adrienne Mayor of Stanford University has suggested that the exquisitely preserved fossil skeletons of Protoceratops and other beaked dinosaurs, found by ancient Scythian nomads who mined gold in the Tian Shan and Altai Mountains of Central Asia, may have been at the root of the image of the mythical creature known as the griffin. Griffins were described as lion-sized quadrupeds with large claws and a raptor-bird-like beak; they laid their eggs in nests on the ground.
Greek writers began describing the griffin around 675 B.C., at the same time the Greeks first made contact with Scythian nomads. Griffins were described as guarding the gold deposits in the arid hills and red sandstone formations of the wilderness. The region of Mongolia and China where many Protoceratops fossils are found is rich in gold runoff from the neighboring mountains, lending some credence to the theory that these fossils were the basis of griffin myths.
In 2016 this hypothesis was contested by Mark Witton, as it ignores pre-Greek griffin art and accounts. Witton goes on to point out that the wings of traditional griffins are positioned above the shoulder blades, not behind the neck as the frills of Protoceratops, that the bodies of griffins much more closely resemble the bodies of modern big cats than they do those of Protoceratops, and that the gold deposits of central Asia occur hundreds of kilometers from the known Protoceratops fossil remains, among many other inconsistencies. It is simpler, he argues, to understand the griffin as a mythical combination of well-known extant animal species than as an ancient misunderstanding of fossilized collections of bones.
Predators[]

Size of the Fighting Dinosaurs
Protoceratops had predators like Velociraptor to keep its numbers down. A famous fossil shows a lone Velociraptor take down a lone Protoceratops. The Velociraptor slashed the herbivore's throat while the Protoceratops bit the Dromaeosaurid's arm and broke it. Both are claimed to have been killed by a sandstorm right when they were about kill each other. This was a very famous fossil preserved until 1971 where it was unearthed by paleontologists.
JPInstitute.com Description[]
This is the first ancestor of the famous ceratopsian family to look like the later, more famous members such as Triceratops. It was much smaller that its more famous relatives, but it was a very successful design that lasted many millions of years. Protoceratops didn't have horns to protect itself, just its sharp beak to bite with.
It is a fairly common fossil, one of the few dinosaurs for which a complete growth history can be seen in fossils ranging from infant to adult. Like other ceratopsian family members each individual shows a difference in the size and shape of its frill. Protoceratops frills were not solid and did not grow overly large. Some scientists believe that the frills may have been brightly colored for display, either to intimidate attackers or for courtship. There are some of this species that show a small horn on the snout. This is thought to be a gender differentiation.
One of the most famous fossils ever found is of a Velociraptor and a Protoceratops locked in battle. They were both killed in the midst of a fight. It is interesting to note that the species name, andrewsii, is for Roy Chapman Andrews. Mr. Andrews was a very adventurous fossil hunter; the movie character Indiana Jones is based on Andrews exploits.
Appearance in other media[]
Jurassic Park[]
- Protoceratops appeared in Jurassic World: Fallen Kingdom as a skeleton displayed on Lockwood Manor.
Read more Protoceratops on Jurassic Park Wiki |
The Land Before Time[]
- Protoceratops appeared in The Land Before Time: How to Draw Dinosaurs.
We're Back! A Dinosaur's Story[]
- Gorbi from Your Pet Dinosaur: An Owner's Manual is a yellow Protoceratops.