One second the lioness seems to be sound asleep as the male delicately approaches her. The next second she is an exploding whirlwind of teeth and claws, and the thunder of her roar drowns any other sound from the surroundings, or from us.
We witnessed this burst of female fury in Northern Botswana during the last edition of our “Drawing the Big Cats” safari, and certainly none of us would like to have been in the place of the scolded young male lion. No real harm was done, but the lioness made a very clear statement.
How to capture the raw feline power of that scene with a simple pencil sketch? I try with a view of the angry face as the lioness snarls at the rearing-up male.
In this early stage I try to capture the general proportions of the cat’s head and the shape of the mouth opening with a few simple lines. It is crucial to get these lines right because I will be spending quite a few minutes with the details of the teeth and palate, and it is sooo frustrating to find out that the mouth was too narrow or the mandible was twisted after you had already wrought the details!
After some more minutes I have given shape to the main structures of the head and mouth, although It seems I will need to go against my own sketching rules and use the eraser after all: the tip of the nose looks to be projecting a bit too far forward!
Some more minutes into the work, and now I am ellaborating on the grayscale. Evolution has provided cats with a fantastic “natural makeup” to boost their emotional expressivity, and their faces are a study in tone contrast. Black lipstick, gothic style, stands in striking contrast against the pale fur of the muzzle, and one needs to be careful in order to show the difference between the dark tones of the lips and the darkness of the oral cavity.
In this provisionally finished stage I have insisted with the dark grey tones of the shadowy background. I remember the charging lioness as a fast moving tawny shape against the dark shade of a thick bush, with the fearsome canines flashing out. To capture this impression I need to spend some more minutes adding pencil strokes until I get a sort of dark mass from which the facial features stand out.
I never tire of quoting pioneer paleoartist Charles Knight when he said that you cannot pretend to be able to reconstruct an extinct animal unless you can properly depict its living relatives. As I further my work on the collection of extinct cat illustrations for my upcoming book project, I find it so useful to sketch time and again the big cats we have encountered in the wild. It is an exercise that never fails to enrich my perception of the animals and to deepen my admiration for them. Drawing is most fun when it implies learning, and sketching the wild cats of Africa teaches me something new everyday!
In a few days we will be heading for Botswana for one more edition of our “Drawing the Big Cats Safari”. Our main goal is to observe the felines, but that is only part of what we get: we actually get a ticket to ancient Africa. The big predators are one key piece in the giant puzzle of living ecosystems, and a place that still can sustain its large carnivores is a place where the laws of nature remain healthily at work, and for that reason I experience every safari as a kind of time-travel.
On each trip, as I board the safari vehicle for the first game-drive, I feel as if I enter a different dimension. Pristine landscapes, untouched vegetation and the diversity of wildlife bring my senses to a state of natural alertness -not in vain human kind evolved in the African savannah! One unforgettable first-day game drive took place in Samburu, Kenya, in 1999. We had spent most of the day driving from Nairobi, and we had only time for a short evening drive through the reserve on our way to the camp for the night. As we drove through the scenic riverine woods along the margins of the Ewaso Nyro river, we found another vehicle that had stopped on the margin of the dirt track: they were watching a female leopard that had just killed an impala ram. Althought the high branches of the palm trees were still golden with the last rays of the sun, the deep bush where the big cat stood with its prey was already in deep shadow. Everyone on board of the vehicles was silent, aware of facing a high natural drama. It was almost as if we didn´t have the right to spy on this decisive moment of life and death, as if both predator and prey were emitting a sort of primeval energy that gave us the goosebumps. We just couldn´t take our eyes from the golden spotted cat and the athletic shape and powerful horns of the fallen antelope. We remained there in awe for many minutes as the cat started to feed and its tiny cubs emerged from the bush, as did an adult-sized young from the previous year, but then we had to hurry for camp.
In later trips I have seen leopards with their prey on several occasions, and each time the prey was an impala. It seems the fates of these two species are tightly linked, but the fact is the impala is an older inhabitant of the African woods and savannahs than the leopard. In Kenya there were impalas (genus Aepyceros) rather similar to the modern ones as early as the late Miocene, some 6 million years ago, while the earliest fossils of leopard ancestors (genus Panthera) are known from fossil deposits of Pliocene age, some 5 million years ago, from the Himalayas. Some time afternwards, leopard-like cats entered Africa, where they are first recorded some 3.8 million years ago, but the ancestral impalas had not been free of predation in the meantime, because several species of sabertooth cats shared their African habitats since the Miocene.
The impala is so well adapted to the ecotone between grassland and woodland, that it has barely changed in 6 million years. Its acrobatic leaps are among the most sublime, if sometimes underrated, spectacles of Africa. We saw this impressive ram in Chobe, Botswana, in 2014
Becuase of my professional bias, during my African trips I can’t help imagining how would those same places look in the distant past, and what animals would occupy the ecological niches of the modern species. If we could travel back to the early Pleistocene, about 1,6 million years ago, we might come across a predation scene where an impala nearly identical to the modern ones would fall prey to a sabertooth cat of the genus Megantereon. About the same size as a leopard, Megantereon would behave similarly to the spotted pantherine in many ways: it would hunt its prey through careful stalking, approaching to within just a few meters before launching an explosive attack. If the kill took place in the grass, the cat would drag its prey as soon as possible to an area with good cover to hide it among the bushes. After all, big hyenas and lion-sized sabertooths (Homotherium) roamed the plains and were always eager to steal the smaller cat’s kills.
But the shape of Megantereon‘s teeth implied some behavioral differences: on one hand, the sabertooth cat would be less able to haul complete large carcasses up the trees, because of its relatively fragile canines. Lighter, partly consumed kills would be easier to handle, although the cat itself was a good climber and at least could always save its own life by climbing to the higher branches.
But the most important difference concerned the killing bite, which implied a lot more bloodshed than in the case of modern cats, and thus if we could see Megantereon within the few minutes after a kill, it would be a rather gory sight.
Here is a reconstruction of Megantereon whitei from the early Pleistocene of Africa, taking a breath as it drags its impala prey to the bush for quiet consumption. Part of my book project “Big Cats of Africa, Past and Present”
Today we still have impalas in Africa, but Megantereon is long gone, a proof of the vulnerability of extreme specialists like the sabertooths and the resilience of adaptable species like the impala -and the leopard. But that doesn’t mean I don´t miss the possibility of seeing such a magnificent beast as Megantereon was!
For a medium sized sabertooth like Megantereon, remaining unseen was of the essence. With its strong, muscular physique it was not nearly a long-distance runner, so it needed to stalk within a few meters of its prey in order to catch it after a couple of spectacular leaps. But its prey, including medium sized antelopes, pigs or even horses, had a lofty ally: the giraffe.
Since the late Miocene, members of the modern giraffe lineage evolved their long necks and tall forequarters, and inevitably became the sentinels of the savannah. From the privileged viewpoint of their 5 meter height, they miss little of what goes on around them
Some 7 million years ago during the Turolian (late Miocene) the giraffid Bohlinia attica had already developed the large size and unique body porportions of modern giraffes. It inhabited the open woodlands of Europe, giving them a striking “African” touch.
Any good wildlife tracker in Africa takes advantage of the presence of giraffes in order to locate the big cats. As soon as a predator moves in the vicinity, giraffes stop their browsing or casual walking, and stand motionless pointing with their stare in the direction of the carnivore. That habit is as convenient for the less tall herbivores as it must be annoying for the predators.
Back in the Pliocene and Pleistocene of Africa, the giraffid Giraffa jumae was a contemporary of the sabertooth Megantereon whitei. While the cat tried to take advantage of every element of the landscape to conceal itself, it could hardly escape the stare of the giraffe, which surely ruined many an attempted stalk!
All cats devote a large chunk of their time to fastidiously taking care of their hygiene and if anything, sabertooths had even more reason to do so.
Right after killing a large prey, as it should do at least once a week, a sabertooth of the genus Megantereon would look like a bloody mess -literally. Unlike modern cats, its killing bite relied mostly on causing massive blood loss to ensure a rapid death of its victim, and that implied a somewhat untidy spectacle. But if we could find the sabertooth at any random moment, chances are we would find a pretty clean animal, which is only what you would expect from a cat.
If we could time-travel and come across the sabertooth Megantereon, it is very likely that it would be grooming itself!
A sabertooth smeared in old blood would be pestered by flies, it would be prone to skin conditions, and would be more easily smelled by potential prey, so it needed to be quite conscientious about its grooming.
But of course there are other benefits to grooming, incluiding the fact, obvious to any cat owner, that it feels good and decreases stress! Social species would benefit from mutual grooming but a solitary animal, as Megantereon most likely was, would need to twist a bit around. But then its long and flexible neck would be a welcome aid in reaching those difficult spots!
The most usual time for me to find long-lost sketches is when I am looking for something else. A few days ago while searching my old folders I came across a few drawings which I thought were lost for good. These included some discarded sketches for the murals of the 1993 exhibit “Madrid antes del Hombre” (in an earler post I shared a few sketches which I did for that exhibit).
The scene which probably changed the most during conceptual sketching was the reconstruction of the Miocene fossil site of Paracuellos. Looking at the site’s faunal list I first envisioned a forest scene where a pack of bear-dogs harassed a chalicothere mother and her young. I just chose from the list the species which looked most appealing to me.
But the scientific advisors tought that the woods actually occupied only a small fraction of the area where the fossils accumulated, so they advised me to show a more open environment. Also they asked me to show other species which were more abundant as fossils at the site, because the bear-dogs and especially the chalicotheres were quite rare finds.
My second version kept the “stars” of the first sketch (the bear-dogs), but they were now cornered in the right-hand section of the scene, leaving room for the more abundant species. Also in this case the victims of the bear-dog attack were not chalicotheres but primitive rhinos.
Unfortunately the scientists found that even this second version did not show clearly enough the inferred environment around the site. Alluvial fans were an important feature of the arid, seasonal landscape, but it was too difficult to properly show them from a ground level perspective. So in the end an aerial view was favoured, and both the chalicotheres and the bear-dogs were totally left out of the scene!
I won´t deny that all these changes implied some degree of frustration for me. I missed the opportunity to turn that chalicothere scene into a full-fledged, large format oil painting. Over the decades I made attempts to include that scene in other projects, but it simply never happened. Who knows, some ideas may be destined to remain forever at the sketch stage!
Modern dogs differ from other carnivores in one interesting anatomical feature: they have a “nuchal ligament”, a string-like structure that runs along the dorsal part of their necks and allows them to support the weight of the head with little muscular effort. Dogs share this feature with ungulates, but there are differences in detail: while in ungulates the ligament extends from the spines of the thoracic vertebrae to the back of the head (hence the name “nuchal”, meaning “attaching to the nape”), in dogs it only runs as far ahead as the second cervical vertebra (the axis), so the term nuchal ligament is somehing of a misnomer here. But, at any rate, what would a carnivore want a nuchal ligament for? Such an adaptation makes sense in a cow or a sheep, who spend many hours grazing with their heads down, an activity that calls for some passive mechanism to save the muscular effort of supporting and then lifting the weight of the head. But carnivores don’t graze, do they?
Well, what dogs do is track scent trails. They walk and trot for long distances, nose close to the ground, as they search and follow their prey’s smelly paths. And they also happen to be relatively long-legged carnivores, which implies they need a long neck for their snout to reach the ground as the animal trots. So the neck of a wolf, jackal or coyote is proportionally very long, but some of the muscles that turn it to the sides and pull it up are relatively reduced, compared to other carnivores, partly because their role is taken by the nuchal ligament.
Here is a drawing of the neck of a wolf (Canis lupus), showing the skull and vertebrae (top) selected deep muscles (middle) and more superficial muscles. See how the “nuchal ligament” actually doesn´t reach the nape, just the back of the axis vertebra.
But, have the necks of dogs always been like that? Several years ago, while working on the reconstructions of fossil dogs for our book “Dogs: their fossil relatives and evolutionary history”, Xioaming Wang, the late Dick Tedford and myself looked in detail at the anatomy of the fossil dog Aelurodon, from the American Miocene. Fortunately there is an amazing collection of fossils of these animals at the American Museum of Natural History in NYC, so we had all the information we could hope for. While studying the cervical vertebrae I found something strange about them: they somehow resembled the vertebrae of a big cat, such as a leopard, more than they did the same elements in a wolf. Concretely, the vertebrae were relatively short, and the processes for muscle attachment were proportionally larger, projecting farther away from the vertebral body. When I assembled the bones to create a reconstruction, the neck looked suprisingly short, and when I reconstructed the musculature of the neck on the basis of the shape and position of attachment areas, it was evident that this animal had a more powerful neck than a wolf of comparable size. There is no obvious evidence for the presence or absence of a nuchal ligament, but the morphology of the back of the axis, where the ligament would attach, is rather different from that of modern dogs. Also, the short neck and its powerful muscles would make the function of such a ligament rather irrelevant.
Here is a reconstruction of the head and neck of Aelurodon. The morphology of the cervical vertebrae (top) implies a relatively short neck, while the shape of muscle attachment areas speaks of very strong musculature (center). Both features resemble the necks of modern big cats. When external layers are added, we see that the animal’s head and neck woudl look powerful and socky (bottom)
These anatomical differences must have implied differences in behavior, but it is not clear what differences those would be. Given the simmilarities with a cat’s neck, it is tempting to assume a more cat-like hunting style for Aelurodon, implying that the predator was more able to handle its prey individually, using its paws to restrict its struggles, and using its neck as a base for delivering a more precise killing bite, a bit like big cats do. Also it is possible that trotting for miles in search of scent trails as some modern dogs do was a less important part of its behavioral repertoire. But it is also possible that the predatory behaviour of Aelurodon was essentially similar to that of modern wolves and it simply had not evolved some of their anatomical refinements.
A broad comparison of neck morphology in fossil dogs revealed to us that the first taxon to clearly show a modern wolf-like neck anatomy was the late Miocene and Pliocene genus Eucyon. This animal also developed proportionally longer forelimbs than any of its earlier relatives, probably reflecting an adaptation to drier, more open environments, and wider foraging areas. So it would make sense to think that a modern foraging stlye in these members of the dog subfamily caninae was accompanied by the development of a modern forelimb and neck anatomy.
Only additional research will take us closer to solve these riddles, but one thing is certain: just like in the cat family, fossil dogs reveal a diversity of adaptations that we could hardly suspect by looking only at the living species. And the dramatic difference that we see today between dogs and cats could have been a bit more blurred in the distant past!
To learn much more about dog evoution and fossil record, check our book:
In 1960, at a time when little was known about the anatomy and body proportions of bear-dogs, American paleontologist Stanley Olsen described a wonderful collection of postcraneal fossils of Amphicyon longiramus, from the Miocene site of Thomas Farm in Florida. Olsen’s paper profiled a kind of predator with no living counterpart. With a body size comparable to that of a modern brown bear, Amphicyon had a longer and more flexible back and a long, heavy tail. Its dentition resembled that of a dog more than that of a bear, and was better suited for consuming meat and bone, while still allowing the animal a varied diet.
In the middle Miocene, when sabertooth cats hadn’t yet attained their full size and dominance, amphicyonine bear-dogs like Amphicyon were the undisputed ruling predators, both in Eurasia and in North America. Although they could not run especially fast or long, they were capable of ambushing large animals using a vaguely cat-like hunting style, and then they could use their great muscular strength and powerful canine teeth to bring down and kill their prey. But with the late Miocene the rule of the bear-dogs was challenged by the appearance of such powerful felid sabertooths as Machairodus. Later relatives of Amphicyon, such as Magericyon, (best known thanks to the fossil sample from Batallones in Spain)adapted to the new times by becoming somewhat smaller and developing more specialized dentitions for killing and consuming large prey efficiently. But there was no resisting the empire of the machairodonts, and near the end of the Miocene the bear-dogs disappeared for good after many million years of successful evolution.
Here is the reference of Olsen’s papers:
Olsen, Stanley J. 1960. The fossil carnivore Amphicyon longiramus from the Thomas Farm Miocene. Part II, Part II. Cambridge, Mass: Harvard University, Museum of Comparative Zoology.
More than 3 million years ago, somewhere in Northeastern Spain, a volcano exploded and created a large crater. With time the crater was occupied by a lake, known by geologists as a maar. Today, the lake is dry and the crater walls have been largely levelled by erosion, but an exceptional fossil site bears witness to the events that took place there. The site, called Camp dels Ninots, is close to the village of Caldas de Malavella in Girona.
Maar lakes often create remarkably beautiful scenery, with their encircling walls covered by forests, but some of them hide something more sinister. One example is lake Nyos in Cameroon, which in 1986 emitted a large cloud of carbon dioxide that killed thousands of people and animals. Such toxic gas emmissions occur because the pocket of magma beneath the lake leaks the carbon dioxide into the water, and perturbations such as those caused by a landslide can cause the gas to emerge with disastrous effects.
Three million years ago around the Camp dels Ninots maar lake, a rich fauna thrived in a subtropical environment, much warmer than today. Rhinos, tapirs and heavy antelopes crossed the forests and came down the crater walls for a drink at the lake margin. But several of those animals died mysteriously at the shore, and their bodies floated into the lake where they ultimately sank. Their skeletons, completely articulated, got exquisitely preserved as fossils, without any trace of having been disturbed by scavengers. A likely explanation is that the lake belched a cloud of toxic gas, instantly killing all the animals along the shore.
As often happens, the animals’ doom was the paleontologists’ blessing, since the death of so many creatures led to their pristine preservation. As the local authorities planned for an on-site exhibit, I was asked to create several reconstructions of the Pliocene environments and fauna of Camp dels Ninots, including a scene showing the hypothetical origin of the fossil accumulation.
And here is the finished painting that can be seen today at the fossil site
The scene shows antelopes of the genus Alephis and a rhinoceros of the genus Stephanorhinus on the shore, already showing signs of intoxication, while a tapir (Tapirus) lies on the ground, already dead. The bodies of other antelopes float in the lake while a pair of cormorants that happened to fly too low are already falling.
This and other reconstructions of the fauna and environments of Camp dels Ninots can be seen as part of the outdoors exhibit. Thanks to the findings made at the site, we now know a lot more about the anatomy of several species of Pliocene mammals, but, alas, no sabertooth skeleton has been found there as yet. But I don´t give up hope.
In central France, another Pliocene maar lake fossil site, a little younger in age than Camp dels Ninots, has been known for about a century, and it has yielded the most complete skeletons known to science of the typical sabertooth cats of the Pliocene: Homotherium and Megantereon. For several decades the French site, known as Senéze, was exploited without any serious excavation methodology, so we don´t know much about the taphonomy of those early finds. But since the 1990s, new field campaigns have yielded more accurate data, suggesting that the fossil mammal skeletons from Senéze accumulated as landslides coming down the crater walls trapped the animals and dragged their bodies to the lake.
I took this photo of the mounted skeleton of Megantereon from Senéze, exhibited at the Natural History Museum of Basel (Switzerland), back in 1990. All other findings of Megantereon fossils are more fragmentary, so it is only thanks to the exceptional conditions of the volcanic maar lake that we know nearly every bone of this sabertooth cat.
Only a portion of the ancient lake shore at Camp dels Ninots has been excavated this far. Sabertooths like Dinofelis diastemata, whose skeleton is mostly unknown, probably inhabited the area at the time, so it is not impossible that the next excavation will yield an amazingly preserved specimen…who knows?
Volcanic eruptions have provided the right conditions for the preservation of some of the best sabertooth fossils known to science, and not only beacuse of maar lake sites. If you want to know more about volcanoes and sabertooths, read my book “Sabertooth”! http://www.amazon.com/Sabertooth-Life-Past-Mauricio-Ant%C3%B3n/dp/025301042X/ref=sr_1_1?s=books&ie=UTF8&qid=1459250381&sr=1-1&keywords=sabertooth
Visit the on-site exhibition at Camp dels Ninots:
It was once thought that the enlarged upper canines of sabertooths evolved as an adaptation to pierce the skin of “pachyderms” such as elephants or rhinos and other gigantic herbivores of the past. But if we need just one proof against such an argument, then the nimravid Eusmilus should be it.
Members of the genus Eusmilus lived in Eurasia and North America in the Oligocene, millions of years before any true felid sabertooth ever evolved. But if we look at the skull of a well known species, such as Eusmilus bidentatus from France, we find that this early animal had taken its sabertooth specializations to a degree not seen even in the late Pleistocene felid Smilodon. Eusmilus not only had very elongated upper canines, but its whole skull was deeply remodeled to increase the biomechanical efficiency of its killing bite. But, while Smilodon was considerably heavier than even the largest modern cats, Eusmilus bidentatus was… smaller than a modern lynx!
Here is a life reconstruction of Eusmilus bidentatus based on Oligocene fossils from France. The animal was heavily muscled and powerful but with a shoulder height of about 45 cm it was shorter than a modern lynx
With its modest body size, Eusmilus could not even dream of attacking any of the thick-skinned behemoths that roamed the Oligocene woodlands and prairies, including many kinds of relatives of the rhinoceros. Eusmilus‘ elongated canines meant that, even with the additional gape provided by its specialized mandibular articulation, the clearance between the tips of upper and lower fangs was similar to that of a lynx. The size of the animals to which it could apply its killing bite was consequently rather small. It is thus evident that the sabertooth adaptations of this predator were not aimed at hunting giant, thick-skinned herbivores, but rather to the quick and efficient dispatching of small and medium-sized prey thanks to a killing bite that caused rapid death through massive blood loss, thus minimizing the danger of a trashing prey escaping or wounding the predator, or both.
Another consequence of its small size was that Eusmilus, like many other kinds of small sabertooths through the Tertiary, was not nearly the dominant predator in its environment. For millions of years, hyaenodonts, bear-dogs, and even the omnivorous pig-like entelodons, have abused these sophisticated but small sabertooths, and stolen their rightful prey.
Small as it was, Eusmilus was not the tiniest sabretooth to evolve. Other species of the genus, like the American Eusmilus cerebralis, was even smaller, and so was the Eocene creodont sabertooth Machaeroides, not taller than a house cat. It is funny to think how nice a pet one of these miniature killers would make, but leaving it to roam in the neighborhood could result in more bloody incidents than any modern house cat can cause…
Want to learn much more about Eusmilus and other mini-sabertooths? Get the award-winning book “Sabertooth” and have your fill of long-in-the-tooth predators! http://www.amazon.com/Sabertooth-Life-Past-Mauricio-Ant%C3%B3n/dp/025301042X/ref=sr_1_1?s=books&ie=UTF8&qid=1454418468&sr=1-1&keywords=sabertooth
Hyenas have long been the victims of human prejudice and superstition, from ancient tribal tales to “The Lion King”. That is a pity because it gets in the way of our perception of a group of amazing animals with incredible adaptations for their ecological niches.
Lions sometimes have a hard time defending their rightful kills against large hyena clans, but quite often it is the hyenas who lose their own prey to opportunistic lions. Such dynamics are not new, and there is every likelihood that the woodlands and prairies of the Miocene, Pliocene and Pleistocene witnessed comparable conflicts quite often.
In the Old World Plio-Pleistocene, it was the lion-sized sabertooths of the genus Homotherium who had to deal with the challenges of living next to a most impressive hyena: Pachycrocuta brevirrostris. This animal was considerably larger in its linear dimensions than the living spotted hyena, but it was also more robust, so its body mass would have been much larger.
P. breviorrostris shared all the adaptations of modern hyenas for cracking bones (massive, blunt premolar teeth, robust skull with a domed forehead) and for carrying large pieces of carcasses over long distances (long, well muscled neck, large scapula with a flat articulation for weight transmission, shortened back and hind limbs for stability). But its massive size took those adaptations to a different scale, and certainly it made the giant hyena a rival to reckon with for any competing predator.
This illustration shows Pachycrocuta cracking a large ungulate bone, and a schematic view of the anatomical features involved in this action. The massive muscles of mastication (temporalis and masseter) provided the huge force necessary to crack the bone with the premolar teeth, and the domed forehead helped to dissipate the stresses generated during the bite
But, was P. brevirrostris a scavenger and a kleptoparasite of predators such as the sabertooths, or did it kill much of its own prey? This is a good question and one to which we may never get a final answer. On one hand, its skull and dentition were adapted to process bone at a phenomenal scale, so it was clearly very well adapted to scavenging. In fact, the cutting blade of its carnassial teeth was slightly shorter than in the highly predaceous modern spotted hyena, leaving more room for the crushing section of the dentition, a detail that suggests a more scavenging lifestyle.
On the other hand, the huge body mass of P. brevirrostris made it less efficient for this animal to forage through the enormous distances required in order to come across such a dispersed resource as carrion is. More purely scavenging species, such as the modern brown and striped hyenas, are much lighter, and actually weight considerably less than the more predatory spotted hyena. And while a large body mass can be a problem for long-distance foraging, it can be an advantage for active hunting, since one or several heavy hyenas can be more effective at subduing and bringing down a large prey animal.
Whether it killed or scavenged most of its food, the fact is that Pachycrocuta had the habit of bringing lots of it back to its den sites, a habit which apparently explains the origin of several remarkable fossil sites. If nothing else, paleontologists need to be grateful to this gigantic bone cracker for its efforts to collect hundreds of bones and gather them in the places where they eventually became preserved as fossils.
A family group of P. brevirrostris gather at the den site, where the cubs play with some old bones. Such dens, when placed near seasonal lakes or waterholes, could be buried by mud during floods and the bones would be preserved as fossils