Protoceratops

About Protoceratops

Features: A Herbivorous Dinosaur with a Huge Head and Strong Jaws

Protoceratops was a small herbivorous dinosaur that lived on the Asian continent, including Mongolia and China, during the Late Cretaceous period.
It had a huge skull relative to its body, and a large frill overhanging the back of its head. Although its name includes "ceratops" (horned face), it did not have large horns like Triceratops, but only small bumps over its nose. It had a sharp, parrot-like beak (rostral bone) at its snout, and distinctive bones sticking out to the left and right on its cheeks.

Its jaws were lined with leaf-shaped teeth, and it possessed a powerful bite force. It is thought to have efficiently chopped up and eaten hard plants such as cycads that grew in the arid environment of the time.

Also, looking closely at the tail bones (caudal vertebrae) of Protoceratops, the neural spines extended toward the back. In the past, some scholars thought it "used them for swimming in the water," but the leading theory today is that they were useful for visual appeal (display) among peers and for thermoregulation.

Dynamic "Posture Shift" with Growth

Protoceratops is known as a dinosaur that experienced a dramatic "posture shift" during its growth process.
Newly hatched juveniles were capable of "bipedalism", walking on just their hind legs when necessary. However, as they grew and their huge skulls and frills developed, their center of gravity shifted forward. To support this, their forelimb bones became thicker and sturdier, and it is known that by the time they became adult Protoceratops, they had transitioned to complete "quadrupedalism".

The Misconception of the "Male's Huge Frill" and Reevaluation of Sexual Dimorphism

For a long time, encyclopedias and museum explanations stated that "male Protoceratops had high, wide frills, while females had low, narrow frills". This was well known as a prime example of "sexual dimorphism" (physical differences between males and females).

However, in recent years, the latest statistical analysis (geometric morphometrics) using skull fossils of more than 29 individuals was conducted, and a surprising fact was revealed. No clear differences in the frills were confirmed at all between the groups considered male and female.

The huge frill, once considered a male characteristic, was actually found to be a "feature that appears in the final stage of growth", highly likely developing in adults regardless of whether they were male or female. The frill is thought to have been a symbol to show that one was a mature adult or for communication among peers, rather than an appeal to the opposite sex.

Fighting Fossil with Velociraptor and Desert Taphonomy

In 1971, a miraculous fossil that shocked the world of paleontology was discovered in the Gobi Desert (Djadokhta Formation). It is a "fighting fossil" preserved in a state where the herbivorous Protoceratops and the ferocious carnivorous dinosaur Velociraptor were locked in a death struggle.

Velociraptor's left hand is grabbing Protoceratops' frill, and the sharp claw of its hind leg is deeply pierced into Protoceratops' neck. Meanwhile, Protoceratops is also crushing Velociraptor's right arm with its powerful beak.

Why was such a tense scene fossilized exactly as it was?
The Gobi Desert at the time was a harsh environment with vast sand dunes. It is thought that they were caught in a severe sandstorm during their fight, or buried deep in the sand alive by a sudden "slump phenomenon" (collapse of a giant sand dune). The rapid and deep burial and dryness unique to the desert prevented scavengers from interfering, resulting in this "miraculous state of preservation" where the bones were discovered three-dimensionally without falling apart.

Parenting and the Discovery of "Soft-Shelled Eggs"

Protoceratops has brought about important discoveries regarding the reproductive behavior and egg evolution of dinosaurs.

The Egg Thief's False Accusation and a Nest of 15 Babies

When dinosaur egg fossils were first discovered in the Gobi Desert in 1923, they were believed to be "Protoceratops eggs" because there were many Protoceratops bones nearby. Then, another carnivorous dinosaur found near the eggs was named Oviraptor (egg thief), labeled as a "thief who came to steal the eggs." However, research in the 1990s revealed that these eggs were actually Oviraptor's own eggs, and far from being a thief, it was carefully incubating its own eggs.

It was much later, in 2011, that a real Protoceratops nest was discovered. Inside a nest about 70 cm in diameter, fossils of 15 babies were buried together.
These babies were not newly hatched but had grown up to about less than a year old. This suggested that Protoceratops stayed in the nest for a long time after hatching from the egg, forming herds with siblings while being fed by their parents.

Dinosaur Eggs Weren't Hard? The Discovery of "Soft-Shelled Eggs"

Even though they were numerous, a long-standing mystery remained after Oviraptor's false accusation was cleared: "Why can't we find real Protoceratops egg fossils?"

In 2020, that mystery was solved. When the black and white substances remaining around the Protoceratops baby fossils were examined using a technology called "Raman spectroscopy", which can analyze components without destroying them, they succeeded in detecting eggshell components (such as proteins).
Upon closer examination, it was found that Protoceratops eggs did not have hard calcareous shells like those of birds at all, but were leathery "soft-shelled eggs" like sea turtle eggs.

This was the moment the common sense that dinosaur eggs = hard shells was overturned.
They had not been discovered until now because soft eggs are unlikely to remain as fossils. Because the parents were too heavy to warm the eggs directly, it is thought that they buried the eggs in moist sand or soil and incubated them using geothermal heat and other sources.

The End of the Origin Theory of the Legendary Creature "Griffin"

There was a romantic theory about Protoceratops that went beyond paleontology.
It was the idea that "ancient people found Protoceratops fossils in the Gobi Desert, and this became the model for the 'Griffin', a monster with the head and wings of an eagle and the body of a lion, appearing in Greek mythology." It was a very attractive hypothesis that they mistook the powerful beak for an "eagle", the four legs for a "lion", and the frill for "wings".

However, this theory was refuted by a study published in 2024.

• Historical Contradiction: Paintings and statues of griffins already existed in Egypt and the Middle East thousands of years before the Greeks heard stories from desert nomads.
• Fossils Aren't Just Lying Around: It is impossible for a dinosaur skeleton to be beautifully exposed on the surface so that an amateur could recognize it as a "monster". Ancient people lacked the technology to extract bones from hard rock.
• Different Appearance: Griffins have supple feline bodies and long tails, but Protoceratops was stocky and stout, so their appearances do not match.

Unfortunately, Protoceratops does not seem to have been the origin of the "Griffin" myth.

Protoceratops Stamp and Fossil Gallery