SABERTOOTH’S BANE: INTRODUCING DINOCROCUTA
Some 8 million years ago, the plains of central China were home to an incredible diversity of wildlife. Herds of antelopes, rhinos, three-toed horses and giraffe-relatives browsed and grazed in the open woodlands and prairies. The imposing sabertooth Amphimachairodus was very much in evidence and could hunt many of those herbivores, but it was not the uncontested ruling predator. There was one monstrous carnivore around that could easily displace the sabertooth from its rightful kills, a creature that we now call Dinocrocuta.
Dinocrocuta was a hyena-like predator, and the similarities made early scholars believe that it belonged in the same zoological family as modern hyenas. But more detailed studies have shown that it actually belonged in a related but separate family, the Percrocutidae, and the remarkable resemblance to modern hyenas is largely the result of convergent evolution. Like the true hyenas, percrocutids evolved adaptations for cracking bones, developing massive premolar teeth and a robust skull with a strikingly arched forehead. But Dinocrocuta took these adaptations to a truly massive scale. The largest living spotted hyenas can weight around 80 kilos, already imposing, but Dinocrocuta doubled and maybe even tripled that mass.
During a trip to China a few years ago I was privileged to study first-hand an incredible collection of Dinocrocuta fossils. It is impressive enough to see pictures of the skull of this animal, knowing that it measures about 40 centimeters in lenght. Seeing massive skull after skull in front of your eyes is a different thing. But seeing a partial skeleton just blows your mind.
Here is a picture of a skull of Dinocrocuta gigantea on exhibit at the Museum of Paleontology in Hezheng, China. This is just one of many such skulls housed in the museum’s collections
As a result of those observations I created a preliminary reconstruction of Dinocrocuta which, for the first time, brought it to life in my mind’s eye as a complete animal.
The resulting picture is that of a somewhat hyena-like animal, but the head is absolutely and relatively far more massive. The combination of a huge body mass, a massive dentition with powerful canines and crushing premolars, and a skeleton well adapted for efficient locomotion on land, meant that this animal could cover large distances in search of carrion, or of its own prey, and that it could evict any other predator from its kill -except, perhaps, another Dinocrocuta!.
In the faunas of the Hezheng basin, Dinocrocuta is the dominant large carnivore in the Bahean-aged sediments, broadly comparable to the Vallesian of Europe with an age estimate of between 11 and 7 million years. Afterwards, with the advent of the Baodean age, it becomes very rare or extinct, its place taken by the much smaller Adcrocuta, a true hyaenid very similar in size and adaptations to the modern spotted hyena. And then Amphimachairodus becomes a much more common fossil occurrence, probably reflecting in part its real dominance in the habitat. After all, dealing with the competiton of Adcrocuta would be more or less like dealing with spotted hyenas for a lion: largely a matter of numbers. But Dinocrocuta was a different matter; trying to stop it from stealing your kill would be like trying to stand in the way of a speeding freight train. And Amphimachairodus was probably wiser than taking such risks.
It is really hard to imagine why such an imposing creature would go extinct and leave its place to the much more modest Adcrocuta. As more fossils of Dinocrocuta are discovered we can expect to see detailed studies that will reveal more and more of its paleobiology, and hopefully we will come closer to understanding the mystery of its final demise.