An Ultimate Guide to Hyaenodon: The Hyena Tooth

Leave a comment / / Updated on: 24th September 2023

Name MeaningHyena ToothHeight1.37 meters (4.5 ft.)
PronunciationHigh-ee-no-donLength3 meters (9.8 ft.)
EraCenozoic – Paleogene to NeogeneWeight40 to 378 kgs (88 to 833 lbs.)
Classification Mammalia, Ferae, & HyaenodontaLocationAfrica, Eurasia, North America

Hyaenodon Pictures

A Hyaenodon in a seated position
A Hyaenodon in a seated position | Masonthetrex0916 via Animals Wiki

The Hyaenodon

Gage Beasley Prehistoric's Hyaenodon Concept
Gage Beasley Prehistoric’s Hyaenodon Concept

In earth’s history there have been several species that have managed to dominate their environment, and outcompete other species before going extinct. 

Hyaenodon is one of those animals, and this carnivorous placental mammal lived in North America and Eurasia around 42 to 25 million years ago from the middle Eocene to the early Miocene epochs. 

While the name Hyaenodon translates to “hyena tooth”, this extinct mammal is not related to the hyena at all, and also had teeth designed for different purposes.

First discovered in 1838, Hyaenodon has around 30 species in their genus, and these top predators managed to dominate various landscapes across the earth. 

There are a few differences between Hyaenodon species, but the most notable were their size, and location.

This article will cover Hyaenodon, and how these species varied across the globe, and what made them the top predators in a time when earth was continuing to change. 

Gage Beasley's Prehistoric Shirt Collection
Gage Beasley’s Prehistoric Shirt Collection
Gage Beasley's Prehistoric Plush Collection
Gage Beasley’s Prehistoric Plush Collection

Physical Characteristics

Gage Beasley Prehistoric's Hyaenodon Size Comparison Chart
Gage Beasley Prehistoric’s Hyaenodon Size Comparison Chart

Hyaenodon was a quadrupedal carnivore, and during their time period were one of the largest terrestrial hunters. 

The skull of Hyaenodon was massive, with a narrow snout, and large teeth, but their brain size was very small for their size.

Hyaenodon had a short neck, with a robust body, and long tail.

There are around 30 species of Hyaenodon, and their size varied greatly, with some being very small, while others weighing hundreds of kilograms. 

The largest Hyaenodon was H. gigas, and this species had a length of around 3 meters (10 ft.), and weighed up to 378 kgs. (833 lbs). 

In North America the largest Hyaenodon species was H. horridus, which had a weight of around 50 kgs (110 lbs.), a length of 1.8 meters (5.9 ft.), and a standing height of around 0.7 meters (2.6 ft).

Life reconstruction of H. horridus
Life reconstruction of H. horridus | Nobu Tamura via Wikipedia CC BY-SA 4.0

Species like H. mustelinus, and H. microdon that lived in the late Eocene of North America were much smaller when compared with their giant relatives, and only grew to have a weight of around 5 kgs (11 lbs.), and were around the size of a small fox. 

The teeth of Hyaenodon were cat-like, while their bodies looked more similar to robust dogs.

Reconstructions of this animal have them covered with fur, with grayish brown coloring, and large heads.

As more fossils are discovered and studies are done how Hyaenodon looked may become more clear. 

Habitat and Distribution

There have been Hyaenodon species found around the globe in places like Africa, North America, and across Eurasia. 

Hyaenodon lived during the middle of the Eocene Epoch, until the Oligocene Epoch around 42 million years, to 25 million years ago. 

These animals first appeared in Africa and Eurasia, and by the time they spread to North America they were the one of  the most geographically widespread, and abundant predators on earth. 

The abundance of Hyaenodon around the globe, and their various species allowed them to live in a variety of habitats from plains, to semi-arid regions. 

Being so wide-spread, Hyaenodon adapted to the various ecosystems around their globe, and their adaptability made it possible for them to migrate into new regions.

During the early Eocene earth had a relatively warm climate, but as the continents shifted to resemble more of their modern day appearance, by the end of the Eocene earth had a much cooler, and dry climate. 

In the Oligocene much of the climate was temperate, and subtropical, with grasslands, and forests becoming more common. 

While Hyaenodon was adapted to survive in multiple climates across the globe, they still were one of the top predators in any environment they lived in.

Behavior and Diet

Hayenodon were carnivores, and at the time were one of the most dominant land predators. 

The large jaws of Hyaenodon is how they killed their prey.

The wide gaping jaws of Hyaenodon elevated it as an apex predator
The wide gaping jaws of Hyaenodon elevated it as an apex predator | La-Artist322 via Prehistoric Life Wiki

With several species of Hyaenodon that varied in size, these animals were not only apex predators, but evolved to fill several types of niches in their ecosystem. 

While the name Hyaenodon translates to “hyena teeth”, their teeth are quite different from hyenas, and serve different purposes. 

Hyaenodon had shearing carnassial teeth, while hyenas had teeth that were made primarily for crushing bones since they scavenged, and fed on carcasses that other animals would have eaten first. 

Hyaenodon also had strong canines, with large premolars, suggesting they were active hunters unlike the hyena. 

Smaller Hyaenodon species would hunt in the night, and group together to increase their success in taking down prey.

The largest species of Hyaenodon could grow as large as a lion, and these hunted during the day, using their immense size and strength to take down their prey. 

A Hyaenodon with a lion-like appearance
A Hyaenodon with a lion-like appearance | Image via Reddit

These animals could only eat meat, as they did not have the right teeth, or digestive system to feed on anything else. 

The teeth of Hyaenodon were used for slicing meat, making it easier for them to digest, instead of having to swallow large pieces of food whole. 

Life Cycle

The life cycle of Hyaenodon is relatively unknown, and it is very difficult to study these animals since they do not have any modern relatives. 

These animals did breed like other mammals, by giving birth to live young. 

When growing Hyaenodons are believed to be slow growing, and fossil evidence suggest they had a long adolescent phase.

As they grew the Hyaenodons teeth would rotate against each other, which would help keep them sharp enough for eating. 

A juvenile Hyaenodon with its skull and teeth partially visible
A juvenile Hyaenodon with its skull and teeth partially visible | Image Reddit

Hyaenodons self-sharpening teeth likely made it possible for these animals to live for very long periods. 

It took around 3 to 4 years for the last of Hyaenodon teeth to appear.

In North America Hyaenodons first upper premolar would appear before their upper molar, while in European species their first upper molars appeared earlier. 

Evolution and History

Hyaenodon was first discovered in 1838, and since their discovery several of these animals’ fossils have been found in North America, Asia, and Europe.

Originally Hyaenodons were classified into the Creodonta order, but in 2015 after a phylogenetic analysis of these mammals they were later placed in the Ferae clade, and are now classified into their own order of Hyaenodonta

Species from order Hyaenodonta
Species from order Hyaenodonta | The Explaner et al. via Wikipedia CC BY-SA 4.0

With more studies the classification of these animals may change in the future, and through the discovery of their fossils there are more than 30 species named.

The current accepted species of Hyaenodon include:

  • Hyaenodon brachyrhynchus
  • Hyaenodon chunkhtensis
  • Hyaenodon dubius
  • Hyaenodon eminus
  • Hyaenodon exiguus
  • Hyaenodon filholi
  • Hyaenodon gervaisi
  • Hyaenodon heberti
  • Hyaenodon leptorhynchus
  • Hyaenodon minor
  • Hyaenodon pervagus
  • Hyaenodon pumilus
  • Hyaenodon requieni
  • Hyaenodon rossignoli
  • Hyaenodon weilini
  • Hyaenodon yuanchuensis
  • Hyaenodon gigas
  • Hyaenodon horridus
  • Hyaenodon incertus 
  • Hyaenodon macrocephalus
  • Hyaenodon megaloides
  • Hyaenodon milvinus
  • Hyaenodon mongoliensis
  • Hyaenodon montanus
  • Hyaenodon vetus
  • Hyaenodon brevirostrus
  • Hyaenodon crucians
  • Hyaenodon microdon
  • Hyaenodon mustelinus
  • Hyaenodon raineyi
  • Hyaenodon venturae

Carnivorous mammals like Hyaenodon first began to evolve during the Paleocene around 60 million years ago, and this not only includes meat-eating mammals, but also omnivores. 

Diorama of Hyaenodon with other contemporary mammals nearly 40 million years ago
Diorama of Hyaenodon with other contemporary mammals nearly 40 million years ago | Chris Light via Wikimedia CC BY-SA 4.0

There have been a variety of carnivorous mammals that lived on earth, with some roaming the land, while others evolved to move through trees. 

Hyaenodonta first began to appear around 42 million years ago in Africa, and Laurasia, and they were the first carnivorous mammals present in their region.

Hyaenodons would later spread to North America, and would continue to evolve to survive in several habitats around the globe before going extinct. 

Interactions with Other Species

Even as other land carnivores began to appear, Hyaenodon still managed to remain at the top of their food chain, but some of the smaller species relied on groups to survive.

Hyaenodon were intelligent, and along with their powerful bites, they had a very strong sense of smell that helped them track down prey.

A Hyaenodon protecting its prize
A Hyaenodon protecting its prize | Masonthetrex0916 via Animals Wiki

Fossils found of Hyaenodon near prey suggested these animals would hunt in places where animals would go often, like watering holes. 

Fossils of animals like rhinos, camels,oreodonts, and primitive horses have been discovered that showed evidence of Hyaenodon hunting them.

In their environments Hyaenodons were not very picky in what they ate, and ambushed prey that was left vulnerable. 

Hyaenodons mainly relied on their strong sense of smell, strength, and sneakiness to ambush prey.

In their environments they were the dominant land carnivore before animals evolved to become quicker and more difficult to hunt.

Other carnivores appearing like bear dogs is what caused Hyaenodons to lose their dominance. 

Bear dogs such as Amphicyon ingens was one of the primary reason for Hyaenodon to lose its top position as an apex predator
Bear dogs such as Amphicyon ingens was one of the primary reason for Hyaenodon to lose its top position as an apex predator | roman uchytel via Wikipedia Public Domain

Cultural Significance

Hyaenodons are a very important species in understanding the evolution of early carnivorous mammals.

With more than 30 species of Hyaenodon, these animals left behind many fossils that have allowed for in depth studies to be done. 

Fossil of Hyaenodon horridus at the National Museum of Nature and Science at Tokyo, Japan
Fossil of Hyaenodon horridus at the National Museum of Nature and Science at Tokyo, Japan | Momotarou2012 via Wikimedia CC BY-SA 3.0

These animals represent the life that appeared in the Eocene, and showcases how carnivorous mammals evolved overtime. 

This species has been shown in games like ARK Survival, where they are known for their strong bites and aggressive nature.

While many depictions of Hyaenodon make them similar to modern hyenas, these animals were very unique, with no relatives alive today. 

Hyaenodon gigas restored in a sketch sheet with multiple pelt variations
Hyaenodon gigas restored in a sketch sheet with multiple pelt variations | Dystopii via Dinopedia

Early mammals first appeared around 225 million years ago and lived alongside the dinosaurs, but when species like Hyaenodon began to appear it would be the start of mammalian dominance around the world. 


Hyaenodons were one of the most dominant animals in their range, and lived across North America, Europe, and Asia during the middle Eocene to early Miocene periods. 

Unlike hyenas, Hyaenodons were active hunters that evolved to fit several niches within their ecosystem. 

Some Hyaenodons were as small as a fox, while others grew to be extremely large, and were comparable to lions, but there were several species in between these sizes. 

While there are no modern animals that are direct descendants of Hyaenodon, scientists have still managed to learn much about these animals from the fossils left behind. 

Along with correcting the mistakes of the past there is still lots to uncover about the Hyaenodon that may be revealed with more research in the future. 

Hyaenodons were one of the first mammalian carnivores to dominate the earth, and once the dinosaurs went extinct there was a gap for a myriad of life to flourish. 


Why did Hyaenodon go extinct?

It is believed that Hyaendon went extinct since it was not able to compete with other carnivores that evolved, and they could not survive with a lack of resources.

Climate change also played a role in their extinction. Hyaenodon went extinct around 25 million years ago, and there are no relatives of this genus alive today. 

Was Hyaendon fast?

The leg length of Hyaenodon suggested they could run, but they were likely not very fast, and their speed could have made it difficult for them to compete with faster species. 

Did Hyaenodon look like hyenas? 

There have been several depictions done of Hyaenodon that look similar to hyenas in their fur and color, but these animals had a much more robust, and elongated skull.

Hyaenodon did have a dog-like body, and while their teeth were similar in appearance to hyenas they were designed for hunting and not scavenging. 


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