Old Earth Ministries Online Dinosaur Curriculum

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From Old Earth Ministries (We Believe in an Old Earth...and God!)

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Lesson 67 - Protoceratops

Protoceratops (meaning 'First Horned Face') is a genus of sheep-sized (1.5 to 2 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 lacked well-developed horns and retained some primitive traits not seen in later genera.

Protoceratops had a large neck frill, which may have served to protect the neck, to anchor jaw muscles, to impress other members of the species, or combinations of these functions. Described by Walter 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.


Quick Facts


Length:  6 feet

Height:  2 feet

Weight:   400 lbs

Date Range:   83 - 70 Ma, Campanian Age, Cretaceous Period



P. andrewsi skeleton at Carnegie Museum of Natural History (Picture Source)



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 fenestra (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 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.
Protoceratops scale
  (Picture Source

Protoceratops was approximately 1.8 meters (6 ft) in length and 0.6 meters (2 ft) high at the shoulder. A fully grown adult would have weighed less than 400 pounds (180 kg). The large numbers of specimens found in high concentration suggest that Protoceratops lived in herds.

Protoceratops was a relatively small dinosaur with a proportionately large skull. Despite being herbivorous, 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. 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.

Discovery and species

Photographer J.B. Shackelford discovered the first specimen of Protoceratops in the Gobi
P. andrewski (Picture Source)
 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 Protoceratops genus, along with fossil skeletons of theropods Velociraptor, Oviraptor, and ceratopsid 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 Late Cretaceous (83.5 to 70.6 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 occular bones) preserved in some specimens.

In 1971, a fossil was found that had a Velociraptor clutched around a Protoceratops in
For detailed images of the Velociraptor/Protoceratops fighting fossil, please visit the Black Hills Institute website.  They sell reproductions of this fossil.
 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 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. 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 the 1920s, Roy Chapman Andrews discovered the first known fossilized dinosaur eggs,
Protoceratops restoration (Picture Source
 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 an angry 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 to actually belong to Oviraptor itself. The original find actually represented Oviraptor brooding behavior.

Daily activity patterns

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.


Protoceratops was the first named protoceratopsian and hence gives its name to the family Protoceratopsidae, a group of herbivorous dinosaurs that were too advanced to be psittacosaurids, but too primitive to be 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.

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Bay State Replicas - Skeleton, skull, hand

Black Hills Institute - Velociraptor vs. Protoceratops fighting dinosaurs