When people think of creatures with tusks, elephants are the first thing that comes to mind.

But now scientists have identified the ancient mammal that had the original protruding teeth — and it It turns out that this strange turtle-like creature lived before the dinosaurs.

Dicynodonts were alive between 201 million and 270 millions years ago. They ranged in size, from small rat-like species to larger species that could be as large as modern-day elephants.

They were first discovered 176 year ago. Scientists found that they had protruding teeth in the upper jaws. However, scientists aren’t certain if they were the first mammal to have tusks. 

Harvard University’s study has confirmed that they were there. It traced the origins of the first tusks back to dicynodonts, and shed light on the evolution protruding tooth by first defining what makes it a “tusk.” 

'Weird' turtle-like dicynodonts (pictured in an artist's impression) that lived before the dinosaurs up to 270 million years ago had the earliest known tusks, scientists discover

Scientists discover that a ‘weird’ turtle-like dicynodont (pictured in an artist’s impression) lived before the dinosaurs. They had the earliest known tusks.

A Harvard University study traced the first tusks all the way back to dicynodonts (pictured) and shed light on the evolution of protruding teeth by first defining what makes a tusk a tusk

Harvard University researchers traced the origins and evolution of tusks to dicynodonts (pictured). They also shed light onto the evolution of protruding dentitions by first defining what makes it a “tusk.”


Dicynodonts, large mammal-like reptiles, were common in the Triassic period where the first dinosaurs appeared.

They existed between 201 and 270 million years ago and ranged in size from tiny rat-like species to some that were as big as modern-day elephants. 

Dicynodonts were discovered for the first time 176 years ago. They had protruding teeth in the upper jaws. However, scientists aren’t certain if they were the first mammal to have tusks. 

Harvard University’s study that tracked the origins of the first tusks back to dicynodonts has confirmed their existence. 

Although elephants are the main modern-day animals associated with tusks, many others also have them, including warthogs, hippopotamuses, Arctic-dwelling walruses, and even a guinea pig looking animal called hyraxes.  

However, they are only found on mammals — There are no known reptiles, fish or birds that have tusks. 

Although dicynodonts do not belong to mammals, they are distant cousins and are more closely related than dinosaurs and other reptiles. 

Harvard’s Harvard study sought to answer the question of how evolutionary steps led to this dental phenomenon, and why mammals are the only ones with tusks today.  

Megan Whitney (postdoctoral fellow at Harvard University) said, “Tusks is this very famous anatomy but until I began working on this research, I never really thought about the way tusks were restricted to mammals.”

Co-author Kenneth Angielczyk, a curator at Chicago’s Field Museum, said: ‘We were able to show that the first tusks belonged to animals that came before modern mammals, called dicynodonts. 

“They are very strange animals.” 

Dicynodonts are well-known for their unusual arrangement of teeth. They had two upper tusks, which came down from the canine position. However, they rarely had additional teeth. 

An example of an ever-growing, true tusk in the dicynodont Lystrosaurus. When researchers cut into the face of Lystrosaurus, the root of the tusks is composed of a wide open pulp cavity that suggests dentine was continuously being deposited

This is an example of a true, growing tusk in Lystrosaurus the dicynodont Lystrosaurus. Researchers found that Lystrosaurus’s root was composed of a wide pulp cavity. This suggests that dentine was constantly being deposited.

Instead, dicynodonts wore a beak at their front that was made from keratin. It resembled a turtle’s beak.

Researchers were on a lunch break during a paleontological dig, when the idea for the study came to them.   

Whitney stated, “We were sitting on the field in Zambia, there were dicynodonts all around,’ 

“I can recall Ken picking them up, and asking why they were called tusks because they had features that tusks do not have.”

Technically, protruding teeth do not necessarily mean that they are tusks. 

Whitney stated, “For this paper we had to define the tusk because it’s an amazingly ambiguous term.” 

The researchers determined that for a tooth to be a tusk it must extend out from the mouth, be made entirely of dentine — therefore lacking the enamel found on most mammals’ teeth — and be ever-growing.

They studied fossilised teeth from 19 dicynodont specimens, representing ten different species, from South Africa, Antarctica, Zambia and Tanzania.

Researchers used micro-CT to determine how the teeth were attached to the skull. Also, to determine if there was evidence of continuous growth.

Some of the dicynodont tusks that the team observed in Zambia didn’t seem to fit the definition of a tusk — they were coated in enamel instead of dentine. 

A dicynodont skull still in the ground that is broken to reveal the roots of their tusks/teeth (the white circular structures)

A dicynodont skull that has been left in the ground to reveal the roots their tusks/teeth (the circular white structures)

Whitney stated, “There are many kinds of dicynodonts, and they all seem to have tusks.” However, Whitney explained, “But, when you look at the micro structural details, they’re very distinct in those groups.” 

Enamel teeth are stronger than dentine. However, due to the geometry of how teeth grow in your jaw, you cannot have an enamel covering. 

Animals like humans evolved durable but hard-to-fix teeth — there is no replacement for the loss of an adult tooth. 

Although tusks are less durable that enamel-coated teeth they can still grow, even if they are damaged. 

‘Enamel coated teeth are an evolutionary strategy that is different from dentine-coated trunks. Whitney stated that it is a trade-off.   

Researchers found that these animals, much like human teeth in terms of replacing teeth at the canine position, had a soft tissue attachment to their jaws. 

This is a unique combination of features, which is interesting. 

Mammals, like humans, replace baby teeth with adult teeth only once unlike most other vertebrates — for instance sharks have continuous teeth production. 

Mammal teeth attach to the jaw via gomphosis, which is a soft tissue, or ligament attachment. Ankylosis is the hard-tissue fusion between bone and tooth that attaches most vertebrate teeth to the jaw.

The enlarged caniniforms of Diictodon have enamel making them more like teeth than tusks. The cross section reveals a ring of enamel around the outside of the tusk that is illuminated under polarised light

The enamel on the enlarged Diictodon caniniforms makes them look more like teeth than tusks. The cross section shows that there is a ring around the outside of each tusk made of enamel. This can be illuminated with polarised lighting

A cross-section through a dicynodont canine under cross-polarised light. The dentine core of the tooth is in grey and the capping enamel is shown in blue/purple. This enamel covering suggests that this caniniform tooth is more like a regular tooth than a true ever-growing tusk

A cross-section through the dicynodont tooth canine in cross-polarised light. The dentine core is in grey while the capping enamel appears in blue/purple. This enamel cover suggests that this caniniform teeth is more like a regular tooth and less like an ever-growing tusk.

Whitney said that Whitney’s two main points, a reduced need for tooth replacement and a soft tissue attachment, allow an animal to grow a tooth without having to replace it.

“Instead, it continues to deposit the same tissue every day. As the animal continues to deposit the tissues, the tooth starts to move out of the mouth and become functional.

The researchers found that true tusk evolution only occurred at a later stage of evolution in dicynodonts — early members of this group had a big tooth rather than a true tusk.

Late in their evolutionary history, dicynodonts developed an ever-growing tusk. Surprisingly, this converged in multiple dicynodont species. 

Whitney said, “I kinda expected there to be a point in the family tree when all the dicynodonts began having tusks. It was pretty surprising that we actually witness tusks develop convergently.” 

“This story is similar in many ways to the elephant evolution story in that it mirrors some of the patterns that were studied on how elephants got their trunks.”

She said that the “tusks” of diicynodonts are what made them so famous.

Brandon Peecook (curator at the Idaho Museum of Natural History) co-authored the article. He said that ‘only a few have true Tusks and the rest have large teeth is a beautiful example of evolution that we can document. We can see how a tusk is made!

Researchers believe that the study, which shows the earliest instance of true tusks in history, could help scientists better understand the mechanisms of evolution. 

Scientists can learn from the different types of teeth that animals have developed about the pressures that led to those teeth being formed. 

For instance tusks can function in a variety of ways including defense, competition, burrowing, sexual selection, and even assist with locomotion — as in the walrus which uses its tusks to hoist itself upon to the ice from the water. 

These dicynodonts may have had a tusk that was constantly growing, which may have helped them overcome the limitations of only having one replacement tooth throughout their lives.

Whitney stated that we don’t know what functions the dicynodonts’ tusks may’ve had because they are difficult to observe and see what they were doing with them. 

“That’s a lingering query about dicynodonts. It’s even more so now. 

The research was published in Proceedings of the Royal Society.


Nearly 66 million year ago, non-avian dinosaurs disappeared and more than half of all species were extinct.

This mass extinction was the catalyst for the rise and development of mammals and the appearance humans.

The Chicxulub asteroid is often cited as a potential cause of the Cretaceous-Paleogene extinction event.

The asteroid crashed into a shallow ocean in the Gulf of Mexico.

The collision created a massive dust and soot cloud, which triggered global climate change. It decimated 75% of all animal and plant species.

Researchers claim that the soot responsible for such a global disaster could only have been caused by a direct impact on rocks in shallow waters around Mexico, which are rich in hydrocarbons.

Experts believe that a tsunami ripped through the Gulf coast within 10 hours of the impact.

Around 66 million years ago non-avian dinosaurs were wiped out and more than half the world's species were obliterated. The Chicxulub asteroid is often cited as a potential cause of the Cretaceous-Paleogene extinction event (stock image)

Non-avian dinosaurs disappeared around 66,000,000 years ago and more than half of all world’s species was extinct. The Cretaceous–Paleogene extinction events are often attributed to the Chicxulub Asteroid (stock photo).

This caused earthquakes, landslides and other problems in areas as far away as Argentina. 

Researchers discovered small pieces of rock and other debris that were released into the atmosphere when the asteroid crashed.

These tiny particles are called spherules and covered the planet in a thick layer soot.

Experts believe that the loss of sunlight caused the complete collapse of the aquatic system.

This is because the phytoplankton basis of almost all aquatic foods chains would have been eliminated.

It is believed that the 180 million years worth of evolution that brought the world up to the Cretaceous point were destroyed in a span of 20-30 years.