Among all the dinosaurs discovered to date, “Spinosaurus” is the most unique and has rewritten many of the established rules regarding theropods.
While its features—such as its elongated skull, crocodile-like teeth, and a body adapted to life by the water—are endless, what captures the imagination most is the giant “sail” on its back, reaching up to about 1.8 meters in height.

Why did one of the largest carnivorous dinosaurs in history, which lived in North Africa during the mid-Cretaceous period (about 112 to 93 million years ago) and is said to have reached lengths of 15 to 18 meters, evolve such a flamboyant structure?
In this article, we will explain in detail the true functions (and the functions it was not suited for) of the Spinosaurus sail, which are becoming clear through the latest research involving biomechanical modeling.

Why Was the “Thermoregulation (Radiator)” Theory Rejected?

One of the long-believed hypotheses regarding dinosaur back sails was that they “assisted in thermoregulation, absorbing or releasing heat.”
This was based on an analogy with the synapsid “Dimetrodon” from about 300 million years ago.

However, this hypothesis was overturned by a paper published in the academic journal “Geological Magazine” in 2016.

Few Traces of Blood Vessels

The neural spines that made up the sail were highly ossified and showed almost no traces of blood vessels.

Lack of Blood Flow

Animals that rely on heat exchange at the body surface possess a massive blood flow just beneath the epidermis, but Spinosaurus fossils lacked this feature.

Because a dense network of blood vessels is essential to function as a radiator or heat pump, the theory that the sail was purely a thermoregulatory organ is currently rejected.

The Most Plausible Interpretation: Its Role as a “Display (Ornamentation)”

So far, the most widely supported theory for the sail’s function is that it served as a visual signal to other dinosaurs, namely an “ornamental trait.”

Even today, prominent visual structures are widely seen, such as the flashy plumage of birds, the giant antlers of deer, and the throat fans (dewlaps) of lizards.
These typically evolve for sexual selection or social signaling.

Appealing to the Opposite Sex and Intimidating Rivals

Because it was visible from a distance whether on land or walking in the water, it was useful for conveying attractiveness to potential mates or assessing the strength of rivals.

Avoiding the Risk of Injury

By showing off its dominance, it may have been used in “ritual combat” to settle disputes without the costs of direct physical conflict.

It is argued that structures like sails develop significantly in species with pronounced differences in appearance between males and females, or in species that exhibit complex social behaviors.

A “Rudder” Underwater? The Semi-Aquatic Lifestyle and Hydrodynamics

To solve the mystery of Spinosaurus, one must look at its entire body, not just the sail.
A 2014 paper in “Science” argued that they were not purely terrestrial, but “semi-aquatic” predators living by the water and underwater.

Fossil Traits Indicating a Semi-Aquatic Nature

High-Density Bones

Assisted in buoyancy control, much like modern penguins.

Webbed or Paddle-Like Feet

Specialized for moving on muddy ground or in shallow waters.

A Tall, Flexible Tail

Adapted for side-to-side undulating propulsion.

An Elongated Snout

Ideal for preying on fish.

Given these traits, it is thought that the sail may have had a “hydrodynamic function” in addition to being an ornament.

Posture Control During Lunges (2021 Study)

A 2021 paper (in the academic journal “Life”) compared the Spinosaurus sail to the drop keel of a boat or the “dorsal fin of a sailfish.”
It argued that when lunging toward fish in the shallows of rivers and lakes, the sail helped maintain balance by reducing rolling and pitching.

Drag During Swimming and Walk Stabilization (2022 Study)

On the other hand, a 2022 paper (in the academic journal “eLife”) suggested through biomechanical modeling analysis that “it did not possess high swimming capabilities like whales or marine reptiles.”
This is because if the entire sail was underwater, it would actually create drag and reduce swimming efficiency.
However, even if its hydrodynamic functions were limited, it is highly likely that it helped “ensure stability” when entering or exiting the water, or when making sharp turns while hunting by walking underwater.

Conclusion: A “One-of-a-Kind Adaptation” Born of Evolution

Current researchers generally agree on the view that the reason for the Spinosaurus sail’s existence “cannot be reduced to just a single function.”

• “Ornamentation (visual signaling)” to mates and rivals
• “Stabilization (hydrodynamic function)” to assist hunting and moving in shallow waters

By fulfilling these multiple complementary roles, it was able to become a one-of-a-kind large predator dominating the rivers and lakes during the Cretaceous period.
Modern biomechanics and computer modeling will likely continue to uncover the process by which evolution integrated form and function, transcending categories like “ornamentation” and “aquatic adaptation.”

When you think of dinosaur skin, many people imagine the hard scales of a crocodile or the bird-like feathers that have been increasingly discovered in recent years.
However, a dinosaur with a “completely new skin structure” that fits neither of these categories and shakes the very foundations of paleontology has been discovered in China.

A new species of herbivorous dinosaur found in strata from the Early Cretaceous period (about 125 million years ago) was covered all over its body with “hollow spikes,” much like a modern porcupine.
We will explain in detail the true nature and possible roles of these unique spikes on this astonishing new species, “Haolong dongi,” which was announced in the academic journal “Nature Ecology & Evolution” in February 2026.

Miraculous Preservation! A Fossil Discovery Where Even Cell Nuclei Are Visible

This historic fossil was excavated from the “Jehol Group (Yixian Formation)” in Liaoning Province, northeastern China, a site world-famous for yielding many extremely well-preserved fossils, including feathered dinosaurs.

As a result of analysis using the latest technology by an international research team, it was revealed that this fossil is a new species of dinosaur belonging to the “iguanodontian” group, and it was named Haolong dongi (meaning “spiny dragon”).
The iguanodontians are an important group of herbivorous dinosaurs that thrived worldwide throughout the Cretaceous period, but this is the first time in the 200-year history of dinosaur research that such skin traces have been found.

Microscopic Internal Structure of the Skin Revealed

Not only did the excavated juvenile specimen retain a nearly complete skeleton, but surprisingly, it was preserved in extremely good condition—to the point where “even the nuclei of the skin cells can be identified under a microscope.”
It is a major discovery of incredibly high documentary value, succeeding in identifying the skin structure of a dinosaur at the cellular level, something that could only be imagined until now.

A “Third Skin Tissue” That is Neither Scale Nor Feather

A detailed examination of the skin fossil of Haolong dongi revealed facts that overturn the common sense of dinosaur science.

Countless “spine-like projections” grew pointing backward over a wide area covering the neck, back, torso, base of the limbs, and tail.
Most are about 2 to 3 mm long, but there were also large spikes exceeding 44 mm among the largest.

“Hollow Skin Tissue,” Not Bone

Even more surprisingly, these spikes were not bones but “tissues originating from the skin,” and their internal structure was a “tube-like structure with a hollow center (hollow cylindrical shape).”
The outside consisted of a stratum corneum (horny layer), and epidermal tissue was preserved inside.

Until now, it was thought that the body surface of dinosaurs was either “reptilian-like scales” or “feathers like those seen in the ancestors of birds.”
However, the research team concluded that Haolong’s spikes are neither pointed scales nor modified feathers, but a “third tissue” with its own unique multi-layered structure.
They had evolved their skin through a unique route entirely unrelated to the evolution of feathers.

Why Covered in Spikes? A Survival Strategy to Become a “Troublesome Prey”

So, exactly why was Haolong dongi clad in these bizarre hollow spikes all over its body?
The research team considered several possibilities and derived the most plausible hypothesis.

Thermoregulation Theory (Questioned)

The possibility that it helped regulate body temperature by increasing surface area was considered, but it is thought that a high heat-retaining effect could not be expected because the density of the spikes is low.

Display / Sensory Organ Theory (Questioned)

This is questioned because there are no traces of pigment cells, and the structure is too large to have functioned as a sensory organ.

The Most Plausible is the “Defense Function Theory”

Currently, the most widely supported theory is that it was a “defensive organ” to keep predators at bay, much like a modern porcupine.
As a juvenile of a gentle herbivorous dinosaur, Haolong was a prime target for the many small carnivorous dinosaurs that inhabited the same area.

While these spikes were not fatal weapons capable of stabbing an enemy to death, they must have been sufficiently effective to make it a “prey that is hard to bite and hard to swallow.”
It is thought that they played a role in reducing the probability of being eaten by making predators hesitate to attack and forcing them to spend extra time and effort.
By turning its whole body into a spiky, “troublesome prey,” it likely tried to survive the harsh struggle for existence.

The Endless Wonders of Evolution

It should be noted that because the Haolong dongi specimen discovered this time is a “juvenile” about 2.45 meters long, it is not known at this time whether these spikes were maintained into adulthood or shed during the growth process.

However, with the discovery of Haolong dongi, a completely new third skin structure—the “hollow spike”—has been added to the history of dinosaurs.
The body surfaces of dinosaurs were not so simple as to be explained by a binary of scales or feathers; they were far more diverse and complex than we ever imagined.
Deep underground, unknown clues that will overturn the next set of common sense are waiting for their moment of discovery even right now.

An iconic scene from the movie “Jurassic Park.”
The deafening “Roar!” of a giant Tyrannosaurus echoing alongside the rumbling of the earth.
For many people, that terrifying yet cool cry is the very image of a dinosaur.

But what if that roar was nothing more than “human imagination,” far removed from scientific fact?

Thanks to recent paleontological research, the mystery of how dinosaurs actually sounded and communicated is gradually being unraveled.
In this article, we will explain in detail the approaches used to uncover the true nature of “sounds” that do not fossilize, a world-first discovery originating from Japan, and the “real sounds of dinosaurs” derived from the latest science.

Why Don’t We Know What Dinosaurs Sounded Like?

As a basic premise, there are no audio recordings of dinosaur “voices.”
So, why can’t we reconstruct their cries from fossils?

Vocal Organs “Do Not Fossilize”

The organs responsible for producing sound (vocal cords, lungs, the syrinx in birds, etc.) are all made of “soft tissues” like muscle and cartilage.
Unlike hard bones and teeth, these decompose quickly after death, making it extremely rare for them to remain as fossils.

Because the mechanics of their vocalizations cannot be directly confirmed, filmmakers have synthesized the cries of various animals—such as lions, tigers, elephants, and crocodiles—to create a highly impactful, “imaginary roar.”

Three Approaches by Scientists

In the absence of direct evidence, scientists deduce ancient sounds from the following indirect clues:

• Comparative studies with modern living relatives (birds and crocodilians)
• Structural analysis of the skull and inner ear (using CT scans, etc.)
• Analysis of rarely discovered fossils from around the vocal organs

Hints About Vocalizations Provided by Relatives (Birds and Crocodilians)

The most important hints for deducing dinosaur voices come from their closest phylogenetic relatives: “birds” and “crocodilians.”

Hints from Birds: A Duck-Like Sound?

Birds are direct descendants that evolved from small theropods.
Birds do not have vocal cords; they sing using a “syrinx” located deep within the trachea.
In 2016, a syrinx was discovered for the first time in the world in a fossil of a dinosaur close to the ancestors of birds from the Late Cretaceous, found in Antarctica.
Among small theropods and feathered dinosaurs, there may have been species that chirped with sharp voices like modern birds, or produced simple sounds like the “quack” or “honk” of a duck or goose.

Hints from Crocodilians: Did Tyrannosaurus Use “Closed-Mouth Vocalization”?

Crocodilians do not roar with their mouths wide open; instead, they use “closed-mouth vocalization,” emitting a low rumble from deep within their throats with their mouths closed.
By vibrating their body cavities, they produce an intimidating, deep bass sound that carries over long distances.

In recent years, the hypothesis that large carnivorous dinosaurs like Tyrannosaurus also used this “closed-mouth vocalization” has garnered attention.
Rather than roaring “Roar!” with their mouths open, it is possible they vibrated their entire bodies with their mouths closed, emitting a low, heavy, rumbling growl that seemed to crawl along the ground.

Vibrating their entire bodies with their mouths closed, emitting a rumbling growl.

The Mechanisms of “Sound” and Hearing Told by Bones

Important information regarding “sound” can also be read from the dinosaur fossils themselves.

A Natural Trombone: Parasaurolophus

The Late Cretaceous herbivorous dinosaur Parasaurolophus possessed a giant “crest” extending far back from its head.
As a result of CT scans, it was found that the interior was a complex tubular structure where air made a U-turn as it passed through.
This is the same principle as a wind instrument like a trombone; it is speculated that by blowing breath into it, they resonated a “low, echoing sound like a trumpet or a foghorn.”

Resonated a “low, echoing sound like a trumpet or a foghorn”

Tyrannosaurus’s “Hearing” Revealed by the Inner Ear

Animals evolve ears so that they can best hear “the voices emitted by their own species.”
As a result of analyzing the inner ear of Tyrannosaurus, it was found that they were remarkably adept at hearing “very low-frequency sounds (infrasound)” rather than high-pitched ranges.
This supports the hypothesis that they emitted ultra-low-frequency growls (closed-mouth vocalization) and communicated by sensing them as vibrations in the air or ground.

A World First! A Major Discovery of a “Dinosaur Throat Fossil” Originating from Japan

Until now, it was thought that vocal organs do not remain in fossils, but in recent years, a Japanese research team has broken through that barrier.

The “Throat Bones” of the Armored Dinosaur Pinacosaurus

A research group led by Curator Junki Yoshida of the Fukushima Museum discovered the world’s first “throat bones (larynx)” of a dinosaur from a fossil of the armored dinosaur “Pinacosaurus” dating back about 80 million years, which was excavated in Mongolia in 2005.

Pinacosaurus

It is a miraculous and major discovery that the throat structure, which is rich in cartilage components, was preserved.

The Possibility of Producing Complex Vocalizations

As a result of the analysis, it was found that the throat of Pinacosaurus had a structure capable of active movement, such as opening and closing, and similarities with modern birds were also found.
It was shown that rather than simply hissing and exhaling breath, they may have been able to deftly control their throat muscles to emit “complex vocalizations” like birds.
While it will take time to recreate their specific cries, this marks an extremely important “first step” in unraveling the evolution of dinosaur vocalizations.

The Real Soundscape of the Dinosaur Age

Synthesizing the latest research results, the Cretaceous forests were likely not a world where giant monsters roared wildly like in the movies.

Small Dinosaurs

Communicating with sharp bird-like chirps or duck-like sounds.

Parasaurolophus

Resonating their crests to call out to their herd with sounds like trumpeting foghorns.

Tyrannosaurus

Keeping their mouths closed while emitting intimidating, ultra-low-frequency rumbling growls that reverberate in the pit of the stomach.

While different from the “Roar!” seen in movies, a Tyrannosaurus producing an unidentifiable, deep bass sound vibrating through the ground from the depths of a quiet forest evokes a far more visceral, biological terror.
Precisely because we don’t know the exact answer, the scientific process of logically deriving sounds from fossils is full of romance and wonder.
The next time you see a dinosaur, please try to imagine, “What kind of voice did it have?”

Among dinosaurs, Triceratops boasts immense popularity right alongside Tyrannosaurus.
When we think of its appearance, the long “horns” above its eyes and the “frill” (neck shield) at the back of its head are famous, but if you observe its head closely, you will notice that the “nose” region is also extremely large and well-developed.

While the “horns” above the eyes and the “frill” at the back of the head are famous, the “nose” region is also extremely large and well-developed.

For many years, the role of this giant nose has been a major mystery in paleontology.
However, in February 2026, a joint research team in Japan, centered around the University of Tokyo, presented a groundbreaking answer to this mystery.
They suggest it is highly likely that the nose of Triceratops functioned as a “radiator” to protect its brain from the heat trapped inside its massive head.

In this article, we will provide a detailed explanation of this latest research, which used cutting-edge methods to reconstruct the “soft tissues” that do not fossilize, unraveling the amazing thermoregulatory mechanism of ceratopsians.

The Overlooked Mystery of the Triceratops’ “Nose”

“Ceratopsians,” represented by Triceratops, underwent extreme specialization during their evolutionary process, developing massive heads.

The Barrier of Soft Tissues and the Difficulty of Comparative Research

Until now, research on ceratopsian heads has primarily focused on the “horns” and “frills,” which were weapons for defense and display.
On the other hand, there has been very little progress in the anatomical understanding of the nasal region, including the giant “bony naris” (nasal opening) that occupies the front of the skull.

Reason 1

The nasal structure of ceratopsians was so uniquely specialized that simple comparisons with other dinosaurs were difficult.

Reason 2

“Soft tissues,” such as the nerves and blood vessels inside the nose, do not remain as fossils, making it supposedly impossible to directly confirm their actual state.

CT Scans Breathe Life into Fossils! Reconstructing Soft Tissues

Taking on this difficult challenge was a joint research team consisting of experts from the University of Tokyo, the National Museum of Nature and Science, the Satsumasendai City Koshiki Museum, the Abiko City Museum of Birds, and Fukui Prefectural University.
(The research results were published in the American Association for Anatomy’s journal, The Anatomical Record, on February 7, 2026.)

Logically Inferring from Bone “Traces”

The research team conducted CT scans on the bone spanning from the snout to the nose (the premaxilla) of Triceratops.
They performed a 3D analysis of the network of fine tubes and grooves (traces where nerves and blood vessels passed through) inside the bone, which are invisible from the fossil’s surface.
Furthermore, by comparing this data with anatomical data from extant reptiles like birds and crocodilians, they adopted a groundbreaking approach to logically infer the existence and layout of the lost soft tissues.

A Unique Network Revealed

As a result of comprehensive analysis, it was found that derived (more highly evolved) ceratopsians possessed unique anatomical features not seen in other reptiles.

Estimating the Major Organs of the Nose

They succeeded in estimating the presence and layout of the “nasal glands” and “nasolacrimal ducts,” which had previously been unclear.

Unique Arrangement of Blood Vessels and Nerves

It was revealed that bundles of nerves and blood vessels called “ophthalmic neurovascular bundles” were predominantly distributed around the giant nasal opening and toward the rostrum (snout).

Complex Folded Structures

The findings indicated the possibility that they had complex, folded structures called “respiratory turbinates” inside their nasal cavities.

The Radiator Function Protecting the Brain from “Heat,” the Weakness of a Giant Head

Why did ceratopsians need such a rich network of blood vessels and nerves around their noses?
The answer lies in the risks associated with their “overly massive heads.”

A Cooling System to Prevent Brain Overheating

The head of Triceratops, boasting one of the largest sizes among terrestrial vertebrates, was covered in thick bone and massive muscles, making it a “structure highly prone to trapping heat.”
Nerve tissues like the brain are extremely sensitive to temperature changes, and if heat is trapped and the temperature rises too much, they suffer fatal damage.
Therefore, a powerful cooling system was essential to keep their massive heads at an optimal temperature.

Efficient Heat Exchange Through Nasal Breathing

This is where the newly discovered soft tissues of the nose come into play.
Through the rich vascular network in the nasal cavity, warm blood comes into contact with the outside air (cold air) with every breath, exchanging heat.
Furthermore, if they possessed the folded structures of the “respiratory turbinates,” the surface area would increase exponentially, dramatically improving heat exchange efficiency.

In other words, the giant nose of Triceratops is thought to have functioned like a “radiator” that cools a car engine.
By circulating a large amount of blood to the snout and inside the nasal cavity to release heat, it protected the vital brain located deeper inside from overheating.

A “More Realistic Image of Dinosaurs” Painted by the Latest Research

While the findings announced this time are a “hypothesis” derived from bone traces, this is the first case to provide detailed anatomical information about the ceratopsian rostrum, an area where knowledge was severely lacking, and its academic significance is extremely profound.

The fact that “their giant noses might have been radiators cooling their brains” tells us that they were not merely sluggish reptiles, but highly active creatures equipped with a highly sophisticated thermoregulatory system.
As this kind of research shedding light on soft tissues that do not fossilize progresses, the image of dinosaurs we envision will undoubtedly be updated into something much clearer and more realistic.

How much food did the giant herbivorous dinosaurs of the Jurassic need to maintain their massive bodies?
In particular, sauropods such as Brachiosaurus are thought to have reached weights of up to 50 tons, and their metabolism and calorie intake have been debated for many years.

A paper published by a research team including the University of Leeds in the UK tackled this mystery with a unique approach: “growing plants by reproducing the atmospheric environment of that time.”
The findings suggest the possibility that they could get by being “lighter eaters” than previously assumed.
In this article, we explain the cultivation experiments conducted in high carbon dioxide environments and the surprising nutritional science revealed from them.

How Did They Maintain a 50-Ton Body? Established Theories and Mysteries

Numerous fossils of giant dinosaurs have been found in the Late Jurassic North America (Morrison Formation) where Brachiosaurus and Diplodocus lived.
However, how they sustained their lives has always been a subject of debate.

The Basis of the “Quantity Over Quality” Theory

The Earth’s atmosphere at that time is considered to have had higher carbon dioxide (CO2) concentrations than today.
Generally, it has been thought that plants grown in high CO2 environments grow faster but have lower nutritional value.
Therefore, the conventional theory was that giant dinosaurs barely maintained their massive bodies by “continuously eating large amounts of low-nutrient plants and spending a long time digesting and absorbing them.”

Recreating Jurassic Air! Actually Growing the Plants

“Did the plants of that time really lack nutrition?” To unravel this question, the research team conducted a bold experiment.

Experimental Environment and Target Plants

In the experiment, they prepared growth chambers with “high carbon dioxide concentrations (400–2000 ppm)” mimicking the atmospheric environment of the time.
There, they actually grew living species close to plants that existed in the Jurassic and measured their nutritional value.

• Ferns: Polypodies, Horsetails (Equisetum)
• Angiosperms: Buttercups
• Gymnosperms: Metasequoia, Ginkgo, Monkey Puzzle Trees (Araucaria)

Measurement via Artificial Digestion System

Furthermore, they fed the grown plants into a “device reproducing the digestive system of sauropods.”
They used cow gastric juices and enzymes for digestive fluids to simulate how much energy could be obtained.

Experiment Results: Only 51kg of Horsetails a Day? Surprisingly High Efficiency

The results of the experiment defied previous expectations.
Even when grown under high CO2 conditions, the nutritional value (metabolizable energy and fiber content) of the plants did not necessarily decrease.
Depending on the plant species, there were even cases where higher nutrition was obtained than in present-day conditions.

Simulation for a 30-Ton Class Dinosaur

When estimating the food intake required for a 30-ton dinosaur to maintain life (assuming a daily need of 280 kilojoules), it was found that there was a significant difference depending on the plant eaten.

• Araucaria (tall tree leaves): Approx. 110 kg/day required
• Horsetails (ground cover): Approx. 51 kg/day is sufficient

It was shown that plants growing in low places like horsetails might have better digestion efficiency and higher energy content than leaves in high places like Araucaria.

Changing the Dinosaur “Population Density”? Significance of the Research

These research results have the potential to change our view of the ecosystem of that time.

Did Brachiosaurus Keep Its Head Down?

While the image of Brachiosaurus is often of it eating leaves from tall trees, considering nutritional efficiency, plants at its feet might have also been an important food source.

Did Brachiosaurus keep its head down?

Reevaluating Population Numbers

The fact that “plant nutritional value was not low” means they could survive on that much less food.
This suggests the possibility that the same area of land could support more giant dinosaurs (higher population density).
The fact that many carnivorous dinosaurs like Allosaurus are found in the Morrison Formation might be because herbivorous dinosaurs, serving as prey, could exist in abundance.

At the end of the Cretaceous period, about 66 million years ago, the dinosaurs that had long reigned as the rulers of the Earth suddenly brought their history to a close.
The most widely supported established theory for their extinction is the “impact of a giant asteroid approximately 10 km in diameter” that struck near the present-day Yucatán Peninsula in Mexico (the Chicxulub crater).

However, in recent years, a new theory proposed by some researchers has been gaining attention: “Could some dinosaurs have survived for a while even after the asteroid impact?”

The Established Theory: The Giant Asteroid Impact and Ecological Collapse from the “Impact Winter”

First, let’s review the currently accepted extinction scenario.
The global, cascading environmental destruction triggered by the asteroid impact was devastating.

Direct Destruction

The shockwave and extreme heat of the impact, followed by the generation of massive tsunamis reaching up to 300 meters high.

Global Wildfires

Forest fires caused by the frictional heat of the kicked-up debris re-entering the atmosphere.

Impact Winter (Cooling and Darkness)

Suspended dust in the atmosphere formed a thick layer that blocked sunlight, plunging the Earth into rapid cooling and total darkness.

It has been believed that this “impact winter” caused a tragic chain reaction: plants withered as they could no longer photosynthesize, the herbivorous dinosaurs that fed on them collapsed, and finally, carnivorous dinosaurs starved to death, resulting in the complete collapse of the ecosystem.

Doubts About the Established Theory and 3 Pieces of Evidence Supporting the “Survival Theory”

If dinosaurs all over the world went extinct simultaneously in a short period, we should be able to find a “graveyard where massive amounts of dinosaur bones are buried together” in a specific geological layer (the K-Pg boundary) somewhere in the world.
However, to date, no such site has been discovered.

Conversely, there are beginning to be reports of dinosaur footprints and bone fragments being discovered in newer geological layers from the era after the supposed extinction.
The main pieces of evidence supporting the survival theory are as follows:

1. Dinosaurs Adapted to the Freezing Cold in the Arctic

What is now Denali National Park in Alaska, USA, was located in the Arctic Circle during the age of dinosaurs.
In this harsh winter environment, fossils of “parent and child footprints” belonging to the Hadrosauridae family (herbivorous dinosaurs) have been discovered.
Since it would be difficult to make long-distance migrations with young who lacked stamina, it is highly likely that they settled in this low-temperature environment and adapted to the cold.
If a species was already adapted to a cold climate, it would not be surprising if they endured the rapid cooling caused by the asteroid impact and survived for a long time.

2. The Isolation Effect of the Supercontinent “Gondwana” in the Southern Hemisphere

The supercontinent “Gondwana,” a landmass comprising South America, Africa, India, Australia, and Antarctica that began breaking apart about 180 million years ago, is another crucial clue.
While the damage from the asteroid impact was catastrophic in the Northern Hemisphere, regions like South America, Antarctica, and Australia were still connected by land (or in close proximity) at the time, forming their own unique ecosystems.
It has been pointed out that this “isolated environment” may have served as a safe haven for some dinosaurs.

3. Fossils Found in Southern Hemisphere Safe Havens

Patagonia Region in South America

Fossils of Hadrosauridae have been reported from sedimentary layers dating to an era newer than the conventional extinction timeline.

Antarctica

At that time, it was relatively warm, and dinosaurs such as Imperobator and Trinisaura lived there.
Fossils of ferns dating to an era 5 million years after the asteroid impact have also been discovered, revealing that the environment was not completely and utterly destroyed.

The Geological Barrier Preventing Confirmation of the Survival Theory: “Reworking”

The discovery of “post-extinction dinosaur fossils” is full of romance and intrigue, but the reason it sparks debate in the academic community lies in the technical limitations of dating geological layers.

When using radioactive elements for age estimation, margins of error of hundreds of thousands of years inevitably occur when measuring strata from tens of millions of years ago.
What is even more troublesome is the phenomenon of “reworking” (or redeposition).
Fossils originally buried in older strata are sometimes eroded out by river currents or crustal movements, washed away, and “reburied by getting mixed into newer strata.”
It is difficult to definitively prove whether a discovered fossil is true evidence of surviving into a newer era or simply a result of reworking, which contributes to the uncertainty of the survival theory.

The Scientifically Proven “Only Surviving Dinosaurs”

It is worth noting that there are scientifically and definitively proven “surviving dinosaurs.”
Those are “birds.”
In modern paleontology, it is common knowledge that birds evolved from theropods (bipedal carnivorous dinosaurs) and are the direct descendants of the only dinosaurs to survive the mass extinction.
Therefore, the phrase “dinosaurs went completely extinct” is inaccurate.
The survival theory currently being debated is strictly focused on whether “non-avian dinosaurs” (typical dinosaurs like Tyrannosaurus that did not evolve into birds) managed to survive.

Conclusion: When and Where Did the Last Dinosaurs Die Out?

Professor Yoshitsugu Kobayashi of Hokkaido University, who has been involved in the discovery of numerous new dinosaur species, acknowledges the possibility that dinosaurs adapted to cool environments could have survived the “impact winter,” and states the following:

“However, even the surviving dinosaurs would have faced massive environmental changes after the asteroid impact. Dinosaurs also had food preferences, and it is believed that because their food disappeared, their populations dwindled over decades, centuries, and millennia, eventually leading to their extinction.”

Synthesizing current scientific evidence, it is not yet enough to completely overturn the established theory that non-avian dinosaurs “went virtually extinct” at the K-Pg boundary.
However, we can no longer completely deny the “possibility that a very small number of dinosaurs survived for a short period—ranging from tens of months to tens of thousands of years—in specific isolated regions or cold climates.”

Rather than dying instantly from the asteroid impact, the last dinosaurs slowly and surely dwindled in number amidst a harsh, rapidly changing world.
As more fossil evidence is discovered and dating technologies improve, the day may come when the truth of what happened 66 million years ago is rewritten even more dramatically.

The extinction of the dinosaurs is considered one of the most dramatic events in Earth’s history and has long been a scientific mystery.
However, the Asteroid Impact Theory, which posits that a giant asteroid collision occurred about 66 million years ago, is overwhelmingly the most plausible explanation today.

The Asteroid Impact Theory is Overwhelmingly the Most Plausible Cause of the Dinosaur Extinction.

This great catastrophe is known as the K-Pg Boundary Event, as it marks the boundary between the Mesozoic Cretaceous (K) period and the Cenozoic Paleogene (Pg) period.
It was one of the largest disasters in history, involving a chain reaction of compound catastrophes and long-term environmental upheaval.

Chapter 1: The Decisive Evidence and Crater Supporting the Asteroid Impact

The strongest foundation for the Asteroid Impact Theory lies in the discovery of “geological fingerprints” in rock layers worldwide and the existence of a massive impact scar (crater).

The Decisive Evidence: The Iridium Spike

Rock layers deposited at the K-Pg boundary show elevated concentrations of the noble metal iridium and other platinum-group elements—over 1,000 times higher than normal levels in the Earth’s crust.
Since these elements are rare in the crust but abundant in asteroids and meteorites, this is considered decisive proof that material from space rained down onto the Earth.

The presence of shocked quartz grains and microscopic diamonds, generated by the immense pressure of the impact, further proves the energy of the colossal shockwave.

The Massive Impact Scar: The Chicxulub Crater

The impact site of the destructive asteroid has been identified as the Chicxulub Crater, located offshore on Mexico’s Yucatán Peninsula.
A giant asteroid, spanning approximately 10 to 12 km, struck the Earth, unleashing energy estimated to be one billion times that of the Hiroshima atomic bomb, creating a massive crater spanning 170 to 200 km in diameter.

Chapter 2: The Moment of Impact: A Chain of Short-Term Catastrophes

The moment the 10-km-wide giant asteroid struck the Earth, the global environment was subjected to short-term catastrophes of unimaginable scale.

The Chain of Short-Term Catastrophes Triggered by the Giant Asteroid Impact

Instantaneous Destruction and a Blazing Wave

At the moment of impact, an immense thermal radiation flash occurred, instantly incinerating creatures within the surrounding region (a radius of 1,000 km).
The colossal heatwave, generated by the vaporization of the Earth’s surface crust, is believed to have reached as far as modern-day Canada.

Mega-Earthquakes and Giant Tsunamis

Immediately after the collision, a mega-earthquake of at least magnitude 10.1 shook the entire planet.
Furthermore, the backwash of seawater rushing into the crater created a giant tsunami that, depending on the coastline, reached up to 305 meters, devastating coastal regions worldwide.

A Scene of “The End of the World”

Approximately 45 minutes after impact, a blast wave traveling at 965 km/h swept across the land, and incandescent microtektites (glass-like spheres) rained down like meteors.
The sky grew dark, and the ground was covered in scorching ash and debris—a scene truly reminiscent of “the end of the world.”

Chapter 3: Long-Term Environmental Upheaval and “Nuclear Winter”

The ultimate cause for the elimination of most life on Earth (over 60% of all species) was the long-term impact on the environment following the collision.

Nuclear Winter and the Collapse of the Food Chain

The massive amounts of dust and soot ejected into the atmosphere covered the entire Earth, blocking out sunlight.
This phenomenon created a condition very similar to the “nuclear winter” predicted after nuclear war, drastically reducing plant photosynthesis and collapsing the foundation of the food chain.
Large dinosaurs, which required huge amounts of food, could not adapt to this environmental upheaval and rapidly went extinct.
Conversely, small mammals, like mice, that required less food were able to survive the extreme conditions.

Acid Rain and Ozone Layer Destruction

As the soot and ash were washed out of the atmosphere, acid-laden rain and mud poured onto the Earth, causing further damage to ecosystems.
Additionally, toxins generated by the massive fires temporarily destroyed the protective ozone layer, accelerating the extinction process.

Chapter 4: Compounding Factors and Latest Research Findings

While the giant asteroid impact is the primary cause, it is reasonable to assume that a combination of factors delivered the final blow to extinction.

The Compound Factor Theory That Delivered the Final Blow to Extinction

The Influence of Volcanic Activity (Deccan Traps)

It is known that massive volcanic eruptions (the Deccan Traps) occurred in what is now the Deccan Plateau in India around the time of the extinction.
While the theory that this activity contributed to the extinction is strong, it is also argued that the greenhouse gases released by the volcanoes may have actually mitigated the effects of the “nuclear winter.”
However, the elemental patterns in the rock layers align most closely with the giant asteroid impact, rather than volcanic origins.

Asteroid Origin Identified (2024)

The latest research in 2024 identified the Chicxulub asteroid as a carbonaceous chondrite meteorite formed in the “outer solar system” beyond Jupiter.
This confirmed that Earth’s history was profoundly rewritten by an “unlucky visitor” from the distant reaches of the solar system, which was unlike the typical asteroids that collide with Earth.

Chapter 5: Extinct Species and the Survivors

Extinct Species and the Life That Survived

The appearance of the giant asteroid brought the 150-million-year history of the dinosaurs to an end.

Extinct Species

In addition to non-avian dinosaurs, large organisms and those at the top of the food chain, which were vulnerable to environmental change—such as ammonites and gigantic marine reptiles (Mosasaurus)—suffered catastrophic damage.

Surviving Species

The birds (Avian Dinosaurs), a branch of the dinosaur lineage, survived and continue to thrive today.
In current taxonomy, “birds are dinosaurs themselves,” so it is more accurate to say that “non-avian dinosaurs went extinct” when discussing the event.
Additionally, small mammals, like mice, survived the extreme environment with limited food, paving the way for the Cenozoic Era, the Age of Mammals.

In Earth’s long history, there existed dinosaurs of a scale incomparable to modern-day creatures.
They were the super-beasts of the Mesozoic Era (Triassic, Jurassic, and Cretaceous), and their names remain as the largest land animals in history.
It is believed that the Earth’s gravity was lower approximately 150 million years ago than it is today, which is considered one reason they were able to support their massive bodies.

Top 10 Largest Dinosaurs in History

This ranking selects the largest Sauropodomorphs based on their maximum estimated total length.
All dinosaurs included in this ranking are Sauropodomorphs, and their overwhelming size tells the story of the dinosaur age.

10th Place: Brachiosaurus

10th Place: Brachiosaurus

Brachiosaurus means “arm lizard,” characterized by its slender forelimbs, which were longer than its hind limbs.
Its height is said to have reached 12m, and it was known as the largest dinosaur for a long time.
It is believed to have lived approximately 161 to 146 million years ago, with an estimated length of 25m and a weight of 23 to 50 tons.
Although its record has now been surpassed, it is a highly famous dinosaur that has long appeared in books, movies, and other media.

Details on Brachiosaurus here

9th Place: Puertasaurus

9th Place: Puertasaurus

It is estimated to have reached 27-30m in length and 50-70 tons in weight.
It lived in South America.

Details on Puertasaurus here

8th Place: Maraapunisaurus

8th Place: Maraapunisaurus

Maraapunisaurus lived during the Late Jurassic period and was distributed in North America.
It was once estimated to be 60m long and weigh 150 tons, but the data is old, and it is highly likely that these figures were an overestimation.

Details on Maraapunisaurus here

7th Place: Mamenchisaurus

7th Place: Mamenchisaurus

Mamenchisaurus lived in China during the Late Jurassic and is known as the largest dinosaur in Asia.
It generally reached 22-35m in length and weighed about 18-30 tons.
It had significantly more cervical vertebrae (19) than other sauropods, meaning its neck accounted for half of its body length.

Details on Mamenchisaurus here

6th Place: Futalognkosaurus

6th Place: Futalognkosaurus

Futalognkosaurus lived in Argentina during the Late Cretaceous and is estimated to be 26-35m long.
It had a thick and robust body structure, with its hip bones measuring 3 meters wide.
It is a valuable specimen, known for being a dinosaur with a nearly complete skeleton.
Its existence spanned only about 3,000 years, and it is speculated that it may have gone extinct due to water shortages caused by the warm, humid climate of the time.

Details on Futalognkosaurus here

5th Place: Sauroposeidon

5th Place: Sauroposeidon

Sauroposeidon lived in North America during the Early Cretaceous and is known as the tallest dinosaur in history.
It reached 27-35m in length and 50-65 tons in weight.
The discovered cervical vertebrae (neck bones) were 1.4m long, and its height is estimated to have reached 17-18m, equivalent to a 5- or 6-story building.

Details on Sauroposeidon here

4th Place: Supersaurus

4th Place: Supersaurus

Supersaurus, meaning “tremendous lizard,” is a type of Diplodocid.
It is believed to have lived in America about 150 million years ago.
It is estimated to be 33-35m long and 40-50 tons in weight, and it is thought that the population of this species was small at the time.
It has long been popular and featured in various media as one of the largest dinosaurs.

Details on Supersaurus here

3rd Place: Turiasaurus

3rd Place: Turiasaurus

Turiasaurus lived in Europe (Spain, Portugal) from the Late Jurassic to the Early Cretaceous.
It is estimated to be 30-37m long and 50 tons in weight. The discovered thigh bone was 1.8m long, making it the largest dinosaur found in Europe.
In the early 2010s, the most complete fossil to date was excavated.

Details on Turiasaurus here

2nd Place: Patagotitan

2nd Place: Patagotitan

Patagotitan, only recognized as a new species in 2017, is second in size only to Argentinosaurus.
It lived in Argentina during the Early Cretaceous and was the largest of the dinosaurs when they began to grow in size. Its weight was equivalent to 10 African elephants.
The discovered femur was 2.4m long and 500kg. Since this fossil was also from a juvenile, it holds the potential to surpass Argentinosaurus.

Details on Patagotitan here

1st Place: Argentinosaurus

1st Place: Argentinosaurus

The dinosaur said to be the largest of all time and all regions is Argentinosaurus.
It lived in Argentina during the Late Cretaceous.
With an estimated length of 35-45m and a weight of 60-100 tons, it is considered the largest dinosaur discovered to date, based on its massive leg bones.
Its weight was more than 8 times that of a Tyrannosaurus and comparable to 20 modern Indian elephants.
Based on its vertebrae characteristics, some suggest it may be a different species from previously known giant dinosaurs.
To sustain its huge body, its heart alone weighed nearly 200kg and pumped dozens of liters of blood with a single beat.
A unique respiratory system that allowed it to take in more oxygen faster than other species was also a factor in its gigantic size.
Its movement was slow due to its immense weight, estimated at 7 km/h (slower than a koala), but its sheer size meant carnivorous dinosaurs left it alone, and it is said the ground shook when it walked.

Details on Argentinosaurus here

The Mystery of Gigantism and Sauropodomorph Characteristics

The reasons why Sauropodomorphs grew to such unusual sizes are thought to include the following:

Self-Defense

Sauropodomorphs, which had low intelligence and were not particularly strong attackers, needed to be large and heavy to protect themselves from carnivorous dinosaurs.
Faced with their massive size, predators had no choice but to give up the hunt.

Securing Food

Their necks grew long so they could eat leaves from high up in the trees, out of reach of other herbivores.

The Largest and Smallest Carnivorous Dinosaurs

Largest Carnivorous Dinosaurs

Although not as large as Sauropodomorphs, there were gigantic species among the carnivorous dinosaurs.

Famous names like “Tyrannosaurus,” “Giganotosaurus,” and “Spinosaurus” are the first that come to mind.

Tyrannosaurus

Giganotosaurus

Spinosaurus

All of these dinosaurs exceeded 12m in length, and Spinosaurus in particular is said to have reached 15m.
However, the prevailing theory generally suggests that Giganotosaurus was the largest carnivorous dinosaur.

Smallest Carnivorous Dinosaur

Conversely, the smallest carnivorous dinosaur is said to have been Microraptor, with a total length of only 50-80cm.

Microraptor

The world of dinosaurs was home to an astonishingly diverse range of sizes, from gigantic kings to palm-sized species.

Limits of Reconstruction and Research

Giant dinosaur fossils are almost always discovered with parts missing, leading to a wide range in estimates of their total length and weight.

Growth Until Death

Unlike mammals, dinosaurs are said to have continued growing throughout their lives, never stopping even as adults.
Therefore, it is highly likely that individuals even larger than those currently discovered will be found in the future.

Difficulty of Reconstruction

There is also the possibility that bones from different species were mixed together, requiring caution in estimation.
However, it is also possible that the size of dinosaurs, which is incomprehensible by modern standards, has actually been underestimated.

The existence of giant dinosaurs, as told by their fossils, conveys to the present day the existence of creatures that surpass our imagination.
Their appearance, as large as a building if they were to appear in a city, is the very definition of romance.

Throughout Earth’s history, dinosaurs thrived for a vast period of approximately 160 million years.
During each era, there were “strongest carnivorous dinosaurs” that reigned at the top of the ecosystem.

This article thoroughly examines the Top 10 Strongest Terrestrial Carnivores in History, spanning different eras and regions, based on a comprehensive assessment of physique, mobility, weaponry (jaw force, teeth, claws), and intelligence, drawing on scientific data and the thrill of paleontology.

Strongest Dinosaur Ranking TOP 10

10th Place: Daspletosaurus

10th Place: Daspletosaurus

“The Fearful Lizard. A powerful hunter specializing in heavily armored prey.”

Specialty

Lived in North America during the Late Cretaceous, and was, as its name suggests, a “fearful lizard.”
It practiced niche partitioning with the more slender Gorgosaurus of the same era, specializing in hunting heavily armored dinosaurs like large ceratopsians and ankylosaurs.

Physique

It boasted a very robust physique, measuring 9m in length and weighing 3 tons.

Details on Daspletosaurus here

9th Place: Siats meekerorum

9th Place: Siats meekerorum

“The hidden king of North America before the appearance of Tyrannosaurus.”

Potential

Lived in North America during the Cretaceous.
Although the discovered fossil was an immature juvenile, its length was estimated to be 9 to 12m, suggesting a potentially much larger size as an adult.

Context

It is highly likely that it reigned at the apex of the North American ecosystem before the fully evolved Tyrannosaurus appeared.
This is a promising dinosaur that could easily break into the Top 3 if new data emerges.

Details on Siats meekerorum here

8th Place: Mapusaurus

8th Place: Mapusaurus

“The South American blade master that hunted super-sized prey in packs.”

Social Behavior

Lived in South America during the Cretaceous.
It is believed to have hunted in packs, which is rare for a carnivorous dinosaur.

Weaponry

Its sturdy jaw was lined with sharp, knife-like teeth, making it adept at slicing flesh and inflicting deep, bleeding wounds that caused its prey to bleed to death.

Physique

It was relatively lightweight for its size and used group tactics to take down super-sized prey (sauropodomorphs).

Details on Mapusaurus here

7th Place: Allosaurus

7th Place: Allosaurus

“The master hunter who reached the Jurassic peak with speed and intellect.”

Mobility

Lived in the Late Jurassic.
It was a master hunter, with running speeds estimated at up to 60 km/h, which allowed it to rely on agile movements.

Weaponry

Its weapons were its agile movements, sharp teeth, and 15cm-long curved claws on its well-developed forelimbs.

Hunting Style

One theory suggests it formed groups and employed efficient tactics that minimized wasted effort.

Details on Allosaurus here

6th Place: Spinosaurus

6th Place: Spinosaurus

“Invincible in water. The largest theropod in terms of length.”

Unique Ecology

At 13 to 15m, it is the longest dinosaur in this ranking.
It is definitively considered to have been adapted for life in water, possessing webbed feet.

Reason for Ranking

As this is a ranking of “terrestrial” carnivorous dinosaurs, its aquatic nature is a disadvantage.
It was not the strongest on land, as evidenced by fossils showing it was attacked by Carcharodontosaurus.
However, in aquatic combat, it would have been unmatched.

Details on Spinosaurus here

5th Place: Carcharodontosaurus

5th Place: Carcharodontosaurus

“The great white shark-toothed blade master, rivaling Tyrannosaurus in size.”

Basis of Strength

One of the largest carnivorous dinosaurs in history, living in North Africa, with a length equal to or slightly surpassing Tyrannosaurus.

Ultimate Slicing Weapon

Named the “shark-toothed lizard,” its sharp, serrated teeth were exceptional at slicing through the flesh of its prey, much like a shark’s.

Weakness

It was significantly inferior to Tyrannosaurus in jaw strength, so it would have needed to rely on cunning when facing opponents with powerful single-strike destructive force.

Details on Carcharodontosaurus here

4th Place: Tarbosaurus

4th Place: Tarbosaurus

“The Tyrannosaurus of Asia. Jaw force with destructive power comparable to the original.”

Basis of Strength

Named the “terrifying hero lizard,” it reigned at the apex of the Asian ecosystem.
Its physique was remarkably similar to the original Tyrannosaurus, specializing in latching onto enemies with its powerful jaw and thick teeth.

Weaponry

Possessed destructive power similar to the original, including powerful hind legs and a whip-like tail.

Reason for Ranking

It is ranked here because it was confined to the Asian region and its overall physique was slightly more slender.

Details on Tarbosaurus here

3rd Place: Acrocanthosaurus

3rd Place: Acrocanthosaurus

“The most terrifying of the Early Cretaceous. A hunter with swift movement and sharp teeth.”

Basis of Strength

Its high physical ability earned it the title of most terrifying during the Early to Mid-Cretaceous in North America.

High Mobility

It was capable of running at speeds of about 40 km/h, boasting very high mobility for a large dinosaur.

Powerful Weaponry

Not only its hind limbs but also its forelimbs were highly developed, making its sturdy claws an effective weapon.

Details on Acrocanthosaurus here

2nd Place: Giganotosaurus

2nd Place: Giganotosaurus

“The South American heavy tank, combining colossal size and agility, surpassing Tyrannosaurus.”

Basis of Strength

At 13m long and 6 to 8 tons, its sheer size surpassed Tyrannosaurus in mass.
Despite its robust build, it was still capable of agile movements.

Weaponry

Its skull was very long, measuring 1.5m. Although its jaw power was less than Tyrannosaurus, it specialized in slicing meat with its sharply pointed teeth.
Its specialty is believed to have been the headbutt.

Hunting Style

Its combat ability is undeniable, as it hunted in groups and preyed on super-sized dinosaurs like Argentinosaurus.

Details on Giganotosaurus here

1st Place: Tyrannosaurus

1st Place: Tyrannosaurus

“The final completed form of the dinosaur, possessing everything necessary for hunting.”

Basis of Strength

The ultimate evolution of the dinosaur, combining the strongest bite force in history with superior intelligence and senses.

Overwhelming Combat Ability

Its jaw force was an astounding 57,000 Newtons (about 3 times that of Giganotosaurus and 6 times that of Allosaurus).
It could easily crush the bones of its prey, immediately demoralizing its opponent with a single bite.

Ultimate Weaponry

Sharp teeth up to 30cm long.
It was an intelligent hunter with stereoscopic vision and a keen sense of smell, allowing it to accurately locate and judge the distance to its prey.

Context

It was an invincible presence that preyed on large creatures like Triceratops and continued to reign at the top of the ecosystem until just before the extinction of the dinosaurs.

Details on Tyrannosaurus here

The Era Cultivates the Strongest

The Era Cultivates the Strongest.

Dinosaurs existed for an extremely long period of 160 million years, during which a single species underwent various transformations and rebirths.
Tyrannosaurus is a prime example.
Early relatives of Tyrannosaurus were small and would not have been able to top the ecosystem, but their eventual appearance as the “completed form” in the final chapter may be the biggest reason for their strength.
If the extinction of the dinosaurs had not occurred, it is possible that other species would have evolved to become even more powerful, potentially preying on Tyrannosaurus.

The Strongest Rulers of the Sky and Sea

This ranking was limited to “terrestrial carnivorous dinosaurs,” but the dinosaur age also had overwhelming rulers in the sky and sea.

Ruler of the Sky: Quetzalcoatlus

Ruler of the Sky: Quetzalcoatlus

Quetzalcoatlus was likely the dominant creature in the aerial ecosystem during the dinosaur age.
Its colossal size (over 10m wingspan) and developed muscles gave it an overwhelming presence as the ruler of the sky.
The fact that it lived during the Late Cretaceous, just before the dinosaur extinction, is evidence that it stood at the peak of its evolution.

Details on Quetzalcoatlus here

Rulers of the Sea: Liopleurodon and Pliosaurus

The strongest predators in the sea were Liopleurodon and Pliosaurus.

Liopleurodon

Liopleurodon

Liopleurodon was a huge, ferocious marine reptile with powerful jaws and sharp teeth.

Details on Liopleurodon here

Pliosaurus

Pliosaurus

Pliosaurus funkei (nicknamed “Predator X”) is considered a top contender for the title of “strongest” due to its astonishing destructive power, with a bite force estimated to be four times that of Tyrannosaurus.

Details on Pliosaurus here

The Strongest Among Herbivorous Dinosaurs

Some herbivorous species also deserved the title of “strongest” due to their immense size or defensive capabilities.
Argentinosaurus, the largest dinosaur ever with an unmatched size, and Triceratops, which defended itself with its formidable horns and frill, are prime examples.

Argentinosaurus

Details on Argentinosaurus here

Triceratops

Details on Triceratops here

Summary

All the dinosaurs featured here were great creatures that reached the pinnacle of their respective eras.
We hope this has sparked your interest in dinosaurs beyond the most major species.

Spiky armor covering their backs and giant tail clubs that could smash rocks.
The dinosaurs of the “Ankylosauridae” family, representative herbivorous dinosaurs of the Late Cretaceous period (about 84 to 72 million years ago), truly possessed an appearance fitting the name “walking fortresses.”

However, even these seemingly invincible creatures actually had a fatal weakness.
In this article, we will explain in detail the surprising latest research (a “digging” survival strategy that overturns established theories) that reveals how ankylosaurid dinosaurs protected their weakness and survived the harsh Cretaceous period.

The Fatal Weakness of the Walking Fortresses: A Soft “Underbelly”

Despite being clad in heavy armor, ankylosaurid dinosaurs had a weakness: a “soft underbelly” that was not covered by armor.
To protect themselves from ferocious, large carnivorous dinosaurs like Tyrannosaurus rex, “how to avoid being flipped over and protect their bellies” was the crucial key that meant the difference between life and death.

For a long time, the established theory in paleontology was that when an enemy approached, they “simply lay flat on the ground and waited it out.”

Established Theory Overturned! “Digging” Skills Revealed by the Latest Research

However, unique research results that cast new doubt on that established theory have been published in the scientific journal “Scientific Reports.”
According to a research team led by Professor Yuong-Nam Lee of Seoul National University in South Korea, it is highly likely that ankylosaurid dinosaurs did not simply lie flat, but protected themselves by “digging into the ground themselves.”

Evidence of “Master Diggers” Told by Fossil Specimens

The research team conducted a detailed investigation of an ankylosaurid skeletal specimen (MPC-D 100/1359) discovered in the 1970s in the southern Gobi Desert of Mongolia (Barun Goyot Formation).
As a result, it was revealed that their anatomical features had a magnificent structure specialized for “digging.”

Shovel-like Forelimbs

The bones of their forelimbs were arranged in a shallow arch, forming a structure like an excavator that could efficiently scoop out soft dirt.

Powerful Anchors

It was a structure where several backbones (vertebrae) were fused, and the number of bones in the hind limbs was also small.
This played the role of an anchor, allowing them to brace and secure their bodies when digging into the ground or swinging their tails.

A Stable Core

Their stocky body shape, which was wide in the middle and narrowed at the front and back, provided the stability to keep their body balance straight even during vigorous excavation work.

Why Did They Dig Holes? An “Impregnable Fortress” and Survival Skills

So, what exactly were they digging the ground for?

“Absolute Defense” to Protect the Vulnerable Underbelly

The biggest reason was to lay out an “absolute defense formation.”
By crouching and sinking completely into a shallow hole they dug themselves, their sides and feet would be guarded by the earth.
In this trench-like state, it would be almost impossible for even the mightiest carnivorous dinosaurs to roll these heavily armed creatures over and target their vulnerable underbellies.
By digging their own holes, they were completing an “impregnable fortress.”

Survival Skills to Survive a Harsh Environment

Furthermore, it is speculated that this digging skill was highly useful not only for defense but also as a survival skill to make it through harsh natural conditions.

Securing Food

Digging up and eating highly nutritious “plant roots” located deep underground.

Securing Water

Locating hidden “water veins” beneath the surface in dry environments.

Nutritional Supplementation

Digging deep into sediments to supplement “minerals,” much like modern African elephants lick rock salt.

A Tough and Clever Survival Strategy

Because similar skeletal features are seen in other ankylosaurid dinosaurs, the research team concludes that it is highly likely this “digging ability” was a basic skill common to the entire group.

These armored dinosaurs survived the harsh Cretaceous period not just by relying on heavy armor and tail clubs, but by digging the earth with shovel-like feet to build their own fortresses.
We can only be amazed by their tough and clever survival strategy from tens of millions of years ago.