Author Archives: chasingsabretooths

Ellesmere’s Early Bear Revealed

A couple of years ago I was approached by my friend Xiaoming Wang and his team of paleontologists with an exciting proposal: to create a reconstruction of a new bear species they were describing from the High Arctic Ellesmere Island. Ellesmere has a magical resonance for me as the legendary place where the biology of wolves was revealed as never before thanks to direct observations of wild packs that were undisturbed by human encroachment. But of course it is also a place of amazing fossil sites, including one called Beaver Pond Site which provides a wonderful window into the high Arctic ecosystems during the Pliocene.

The first step for my reconstruction was to draw the ancient bear’s skeleton using photographs and measurements of the fossils. Many bones were missing from the site and had to be drawn on the basis of those of living relatives, but still there was enough material to create a reliable approximation fo the animal’s body proportions. The resulting skeletal drawing shows an animal of moderate size, not very different in build and mass from an extant black bear.

A vital part of the reconstruction was to create an accurate rendition of the animal´s face, and for that we had the benefit of a remarkably well preserved partial cranium and mandible. In fact the team sent me a 3D scan of the skull which allowed me to visualize the fossil from any point of view, choosing the best angle to show the bear’s “personality” to advantage.

In this 4-step sketch you can see the process leading from the original render of the digital 3D scan of the skull, followed by the definition of the main muscle masses and the addition of cartilage, skin and fur to complete the outline of the living animal’s head.

The final stage of the reconstruction was to place the animal in a natural setting. The High Arctic Pliocene environment was reconstructed with the help of copious paleobotanical data provided by members of the team. In the background you can see a beaver hard at work in the maintenance of the pond that gives the fossil site its name, and which was an important factor in the local environment.

Nowadays there are no beaver ponds in Ellesmere but its hardy wildlife, including its amazing white wolves, is key for understanding and restoring wild ecosystems through the Holarctic, a kind of reconstruction that is very different from paleoart, and one that we should master if our species is to survive in the long term.

Check the original scientific publication here:



Mysteries still remain around the killing bite of the sabertooths, although it seems clear that they relied on a combination of a huge gape and a surgically precise cut through the softer parts of their prey (such as the throat) to achieve a rapid death through blood loss. Modern big cats on the other hand use a different technique, applying strong and prolonged pressure with their short and robust canines, either suffocating their prey or crushing vital parts.

Among the pantherine cats, it is difficult to imagine a killing bite more different from that of sabertooths than the one employed by jaguars in South America to hunt caimans. What sort of anatomical adaptations allow the jaguar to deliver a bite devastating enough to kill a creature that boasts one of the most formidable armours in nature? In a recent assignment from National Geographic Magazine we set to explore precisely that subject, and how to reflect it in images.

Research into the anatomy of the skull of pantherines by several specialists has shown that the skull of the jaguar is adapted for generating larger bite forces than other big cats, due to slightly increased jaw leverage and to the larger cross-sectional area of the masticatory mucles, especially the temporal and masseter. But the differences with other species of the genus Panthera are subtle and there is also a behavioural factor, a preference (either genetically programmed or learned, or both) by the jaguars to go for a skull bite where other big cats would aim at the prey’s neck. When the chosen prey is a large caiman, as often is the case among jaguars from Brazil’s Pantanal, the efficiency of the skull bite is simply astounding. As the jaguar usually surprises the caiman from above and behind, the skull or nape bite is simply the best way to bite and not be bitten by a prey that can revolve and snap its deadly jaws with lightning speed.

Jaguars in the Pantanal spend lots of time patrolling the water margins in search of such prey as capibara or caimans. Photo courtesy of Luke Hunter/Panthera

Caimans are an important part of the Pantanal jaguars’ diet, wether they actively hunt them or scavenge them as in the case of this picture. Photo courtesy of Rafael Hoogesteijn/Panthera

For the National Geographic illustration, art editor Mónica Serrano proposed to work in layers so that we would have freedom to decide what parts of the anatomy of both predator and prey to show.
After all, the killing bite is an interaction between the geometries of both animals and the jaguar needs to allign its head and jaws in a very concrete position in order to penetrate the caiman´s superb armour. This interaction is so compex that there is no hope to show all the relevant factors in one single, 2-dimensional image.

My first pencil sketch, based in a draft sent early on by Mónica, shows the jaguar´s head in near-frontal view, which is the only way for us to show the relevant features of the caiman’s head and neck in a recognisable way

By choosing a frontal view we lost the opportunity to show clearly one important aspect of the jaguar’s killing bite: gape!

Although the gape of modern cats is small compared to that of the sabertooths, they are still capable of opening their jaws to an impressive degree as shown in this picture. Such gapes are neccesary if the jaguar has to encompass the head of a large caiman between the tips of its canines. Photo courtesy of Luke Hunter/Panthera

Once we established the angle of view, I proceeded to draw the anatomy of both animals from the inside out. This is an excercise I am pretty familiar with from my reconstruction work, but in this case I have the advantage of working from images of dissections and CT scans of the real animals, rather than having to infer the development of muscles from their attachment areas in the bone only.

I started by drawing the skulls of caiman and jaguar in a position corresponding to the killing bite

In the next layer I put the muscles in place. In jaguars, the great width of the area encompassed by the zygomatic arches, known as the temporal fossa, is a clear sign of the huge development of its temporalis muscle

In the final layer, I show the external appearance of the animals, with the armour of the caiman much in evidence

At this point in the process there was still an important task ahead: to select what sections of the deeper layers to show through. That was up to Mónica and her team, who produced the published image as we see it here

Using transparency and additional outlining it was possible to show the position of the jaguar’s mastication muscles, the caiman´s neck vertebrae and even its tiny brain.

In this video you can see the whole sequence of images, from the early pencil sketches to the layers of the colour illustration, and you can appreciate the difficult choices about what to show and what to hide.

See the National Geographic article on jaguars as published in the December issue of the magazine in this link:

All artwork by Mauricio Antón, ©National Geographic

The Great Ibex Showdown

The complex shape of the ibex horns has evolved over millions of years for a very particular fighting style. You can study the morphology of the horn sheaths, horn cores and skull and see how the whole structure is reinforced to withstand the brutal blows, but to fully understand the relationship between form and function you need to see the real animals fighting each other. In one modality of their ritualized choreography, one of the contenders raises on his hind legs and gets ready to fall on the defender, who in turn adjusts his position to receive the attacker. As the impact becomes imminent, each animal orients its head quite precisely so that the forces will be properly channeled. In other occasions, both contenders raise and the trajectories towards impact are more symmetrical.

With extinct animals we can only infer their fighting styles from the morphology of their skulls and head appendages, but with living animals there is no end to how much we can learn by observing directly their real behavior. Such observations help us anchor more solidly our hypothesis about the habits of completely extinct beasts.

In this photo taken by my son Miguel, you can see two standing contenders about to start their descent, their laterally placed eyes fixed intently on each other as they prepare for the impact

In this other picture you can see the classic fight modality where one contender is distinctly above the other

This image shows the moment of impact, when even the hind legs stretch to liberate the immense energy of the blow

To see the whole process in action, check the second part of my Spanish ibex video here:

Making Music for Nature Film

In my daily work I rarely keep art and science far apart. Science aims for total, detached objectivity, but I don´t think such a thing is possible for us humans, and certainly it is not something I can attain! Each observation of nature implies some emotional involvement, and for better or worse in all my productions those emotions end up coming to the surface in some way.
One aspect of this involvement is the music I compose for my videos. Reconstructing the anatomy of the sabertooths from the inside out is quite exciting, but the kind of emotion it stirrs in me is rather different from the one I experience when observing a violent clash between two imposing ibex males in the high mountians. As a result, videos showing such different contents require different, specific music, and I try to taylor make it or at least to choose from my existing compositions as wisely as I can.

In this clip from my video “Bringing the Sabertooths back to Life” you can listen to the more “electronic” sounds I used in many segments of that film, to convey a sense of how a careful technical study leads to exciting findings. In my wildlife videos I generally use more orchestral sounds to transmit the warm, direct emotions that you get when watching the dramas of animal life out in the wilderness:

Earlier this year I discovered Hans Zimmer’s masterclass on composing for film and decided to take it. Even from a quick look at the first lessons one feels exhilarated at the endless possibilities that music offers for enhancing and completing any film project. Mr. Zimmer is not only a genius, he efficiently and honestly transmits both the excitement and the tehcnical aspects of his craft.

As a first excercise while taking that course, I composed a piece of music for a short video about the behavior of the Spanish Ibex. Following Zimmer’s instructions, I started by composing a short, simple piano tune, as a core from which I would create all the variations that the story required. In that tune I tried to convey the basically sweet, harmless nature of the ibex, but it also contains a couple of chords with the potential of becoming more aggressive, as befits the powerful clashes of the males during the rut, or more mysterious, to reflect the vastness of what we don´t know abut the caprine mind.

In this other clip you can listen to some of the more “epic” sections of the soundtrack I composed for the ibex film:

Using brasses and timpani was a temptation I could not resist, but anyway I tried to dress the tune in warmer strings and even a playful harp to compensate for the in-your-face obviousness of the percussion. The big male ibex go at each other with devastating, almost murderous blows, yet the next moment they seem to behave as comrades, almost buddies. It is more complex than an all-out war, and so the music should also have something of that ambiguity.

Of course when you see Zimmer’s explanations it all appears so obvious, but for us mortals things are not nearly so simple! As I developed the themes my original piano piece seemed less and less adequate, and it constrained me unconfortably, but I decided to go ahead anyway. The result is far less elegant and effective than I dreamed when listening to the classes, but still a small step up the ladder from my previous compositions.

Learning from the best is deeply humbling but always exciting. Thanks to Mr. Zimmer and I promise to keep working hard as I progress through the course!

Swift pussy cat: Batallones’ little feline wonder revealed

The fossil sites of Batallones provide amazing insights into the predator guild of the Vallesian epoch (Late Miocene, 9,5 Ma) of Spain, and are best known for the incredible collection of fossils of sabre-toothed felids, including the leopard-sized Promegantereon and the lion-sized Machairodus. A less known fact is that the other “half” of the felid family, the felines (or “conical-toothed cats”) were already present and represented by a respectable sample of fossils at the site.
Those early relatives of our modern lions and tigers posed no threat for the sabertooths, because they were all much smaller animals. Two species are known from the site, the lynx-sized Pristifelis attica and the wildcat-sized Leptofelis vallesiensis. Years ago, in our initial description of the animal we called it Styriofelis vallesiensis because its dentition was very similar to that of earlier, Middle Miocene felines classified in the genus Styriofelis. However, our recent analysis of the postcranial bones of the small feline from Batallones has revealed unexpected differences with those earlier animals.
The middle Miocene Styriofelis turnauensis combined peculiar dental traits (in particular the retention of milk premolars in adult life) with a skeleton adapted for climbing, with short, robust limb bones. Such a skeleton can be considered “primitive” for felids, because the ancestral members of the family were mostly arboreal creatures. The small cat from Batallones shared with Styriofelis the retained milk teeth, but its limb bones now reveal a surprisingly early adaptation for fast, efficient locomotion on land. This condition almost mirrored the one seen in modern animals like the wildcat, but it most likely evolved independently, because the particular dental features preclude Leptofelis from being an ancestor of the modern species. In fact, the skeleton of the Batallones small cat is in itself a mosaic of features, including the presence of a well-developed quadratus plantae muscle inserting on the ankle bone. This muscle has an important function in climbing and it shows that in spite of being a proficient runner, Leptofelis vallesiensis could climb better than most modern cats, both to escape bigger predators and to catch small prey in the high branches. Also the hind limb was especially long and the knee articulation resembled that of modern small carnivores that are excellent jumpers and climbers, such as the genet. It is possible that Leptofelis used its leaping ability to capture small prey such as rodents and birds while foraging on the ground, like modern servals or caracals do. This unique combination of features convinced us of the need to create a new genus for this cat, and we coined the word “Leptofelis”, meaning “swift cat”.

In this illustration we show some of the preserved bones of Leptofelis superimposed to a hypothetical reconstruction of its complete skeleton.

There are many things we have learned from this study. On one hand, the early diversity of felines is greater than was thought some years ago, when virtually all fossil felines from the late Miocene were classified in the extant genus Felis. On the other hand, we see that the adaptations of feline cats for running not only appeared more precociously than thought, but in fact evolved several times independently. Also important is the fact that the postcranial skeleton, often overlooked in systematic studies, can provide decisive evidence for the proper classification of an extinct animal. And, finally, if we look at the larger picture, it seems that the combination of the small size of the early felines, the need to escape from larger predators, and the presence of vegetational cover in their environments probably provided the right adaptive pressures which led (more than once) to the evolution of the versatile body plan that we see in modern cats.

Here is a reconstruction of Leptofelis in the flesh. The coat colour patter is unknown in this animal and here it is reconstructed on the basis of species such as the marbled cat, whose coat markings appear to represent the ancestral patter for all living felines.


You can check our original research paper in this link:

Ibex wonder

The Spanish ibex is a spectacular species of caprine endemic to the Iberian peninsula. Powerful and bulky like other ibex, the Spanish one has possibly the most beautiful, geometrically complex horns of any species. Like all ibex, this creature has been perfected by evolution for two functions: to negotiate the abrupt terrain of its mountainous habitat, and to establish the herd’s mating hierarchy through dramatic horn-clashing fights among the males.
Drawing the three-dimensionally complex horns of mature Spanish ibex is always a challenge but when you get it right you are on your way to capturing the knightly grandeur of these magnificent beasts. Still, nothing compares to witnessing the incredible tournaments that take place in the mountains of central Spain with the autumn cold. Just seeing these creatures moving nimbly up and down their rocky environment is amazing, but when the loud crash of horn hitting horn echoes in the high valleys you feel transported to the Pleistocene. Life still follows its age old laws up there and we are privileged to witness it.
I will soon be sharing with you a video showing some of the majesty of the Spanish ibex in action. Meanwhile here is a page filled with my quick, humble attempts to grasp the essence of the ibex.

Building a Pleistocene Pampean Panorama

When facing the challenge of creating a reconstruction of such a fantastic fauna as the ones found in the late Pleistocene of Argentina, the real difficulties are to decide what to leave out and, even more, how to arrange what you cannot leave out.
As it has happened so often in this kind of projects, the paleontologists I worked with insisted that I include at least the most iconic members of the fauna, and that included a lot of huge animals that you cannot easily accommodate under a log or in the shade of a bush. These creatures become relevant elements of the landscape on their own right so as an artist you have to brace yourself for a tightly packed composition.

The first thing I did was to try and visualize the general shape of the scene, using very fast, light pencil strokes to block the main objects. In this early version I still thought I would get away with excluding the largest Pampean animal of them all: Megatherium! But that was not to be

In the next quick sketch I let the megathere in, and instantly things got almost unmanageably crowded

One advantage of the Pampean landscape in terms of this kind of compositions is its flat, featureless lay. Vast expanses of land with unobstructed views allow the hapless artist to place a lot of gigantic animals in the frame, but careful attention must be paid to perspective. So, even in this quick sketch I trace the perspective lines to get an approximate idea of the relative sizes of the various animals according to the distance from the viewer

Once the main composition is decided, I need to do a lot of sketches of the anatomy and action of the individual animals. The pair of Macrauchenias in the foreground were an important element of the composition from the very first version, so I needed to study their anatomy carefully

Although the sabertooths are dearest to my heart, I made up my mind to leave them in a discrete middle ground in this case, but even so they are prominent and I needed to do a lot of work on their postures

Especially important is the head of the drinking sabertooth, so I used a cast of the animal’s skull as a guide to draw the head in the exact angle and posture I needed

The advantage of working digitally is that I paint the animals in separate layers, so I still can do small tweaks to the composition as I go along working on the final painting

This painting was reproduced at mural size in a Museum exhibit here in Madrid so I needed to give it a lot of detail. In the end I suppose it took me about as long as it would have taken to do one of my large oil paintings but I enjoyed more freedom for changing my mind on smaller aspects of the work… and I got more back pain form hunching in front of the computer for so many hours. Sometimes I do miss the easel!

But the one thing that left me frustrated in this project was to double-check the plant list from the fossil sites and find out that I needed to leave the palm trees out. Damn, I love palm trees!

A deeper look at the cheetah

The process of reconstructing extinct animals is like a dissection in reverse, where one adds soft tissue layer by layer on top of the animal’s skeleton. But in order to be prepared to work in such a way, it is necessary to get familiar with the inverse process, that is, proper dissection of extant animals. I have taken part in many dissections of big cats in collaboration with the University of Valladolid and the Paleobiology department of the Museo Nacional de Ciencias Naturales. Those dissections have allowed me to acquire first-hand knowledge of the feline anatomy, and to understand in more depth the differences between the various species of big cats.
One good example is the cheetah. We know this animal as “the feline greyhound”, and its lean appearance is obviously related to the considerable length of its limb bones relative to its body size, but is that all?

This drawing of the cheetah skeleton shows the gracile proportions and elongated limbs of the fleetest living cat

Well, the fact is that the cheetah’s muscles are arranged in a different manner than in other big cats. In the limbs, the bulk of the muscle mass is concentrated in the proximal segments (that is, those closest to the animal´s trunk), while the distal parts (those farthest from the trunk) hardly retain any muscle mass at all, and it is mostly tendons, not muscle fibers, that reach those segments.

The musculature of the cheetah is that of a true runner, with limb muscle masses concentrating near the animal´s trunk and little more than tendons reaching the paws

The external appearance of the cheetah betrays its lean proportions, but many details are obscured by the arrangement of the fat tissue (little as there is…), skin, and fur

Such a particular arrangement of the muscles is reflected in the shape and position of the muscle insertion areas in the animal´s bones, something that we can track as dissection proceeds deeper inside. Sketches and photographs record all the findings made during the process, and it is this kind of observations which in turn allow us to restore the lost musculature of extinct animals using bone morphology as a guide.

This series of sketches shows the process of dissecting the cheetah´s forelimb, starting with the intact limb (top) and ending with the bare bones (bottom). Of course this is just a selection from several sketches showing different stages of the dissection

Unfortunately dissection is a destructive process and once the tissues are removed from the specimen there is no putting them back in place. But fortunately we have the option of scanning the intact specimen before dissecting it, as we did with this cheetah. CT scan imagery allows us to check time and again the relationships between soft tissue and skeleton, looking at those structures from any angle and using perspectives we couldn’t check during dissection.

Here we see a screen capture of our CT scan of the cheetah forelimb, showing the relationship between the animal’s bones and the´soft tissue outline

Observations like these pave the way for my work in the anatomical reconstruction of extinct carnivores, but it also gives me a renewed, deeper look at modern big cats. Whenever I see a wild cheetah moving around in its environment I perceive the lever system of its bones, muscles and tendons working right under the skin, and my admiration for these wonderful creatures grows even more.

You can learn much more about these processes of dissection and reconstruction in my film “Bringing the Sabertooths Back to Life”, available for download at Wild World Visuals online store:

The Deinothere’s Forest and the Noah’s Ark Trap

Let me share now the genesis of yet another of the oil paintings I did for the “National Geographic Book of Prehistoric Mammals”. That project left me a bittersweet taste because on one hand it allowed me to create a series of scenes I had longed to do for quite some time, but on the other hand the deadlines were so tight that I barely had the time to enjoy the process -or even to think much about what I was doing!
This painting depicts a scene from the Early Miocene of France, a time when the faunas of Europe, previously more isolated, were enriched by the arrival of immigrant species from Africa, such as the proboscideans, and from North America, such as the horses.
As happened with many of my illustrations, this idea had been on my mind for years and it had been left out from a previous project, in this case from the book “Mammoths, Sabertooths, and Hominins”. Like other scenes intended for that book, I planned it as a vertical composition, in order to fit the design constrains of that volume, so when I recovered the idea for ·”Prehistoric Mammals” the first thing I had to do was to change the format to horizontal.

Here is the first concept sketch for the scene, back when it was planned to be a vertical composition for “Mammoths Sabertooths and Hominids”

Once I redesigned the scene I also decided to make my life a bit simpler by excluding the primitive deer from the composition. The primitive deinotheres (Prodeinotherium), the three-toed horses (Anchitherium) and the mongooses (Leptoplesictis) together with all the greenery, were enough to keep me busy for a good while.

Here is the preliminary pencil sketch for the horizontal version of the scene

As in the other examples I have commented previously, I went for a rapid color sketch where I established the basic palette I would use in the final painting.

Here is the quick color sketch

One final step I always took before attacking a big canvas was to make a schematic outline of the final sketch and draw a grid on top, to help me transfer the composition faithfully to the bigger format. In this step I omitted one of the Anchitherium horses, in order to simplify things a bit more and also because it looked odd that the head of the poor creature was hidden by the deinotheres…

Here is the line sketch with the grid for transfer

So I finally started painting, and only then I realized that, not for the first time, I had fallen in the dreaded “Noah’s Ark Trap”. By this I mean an unconscious propensity of mine to include always two individuals of each species in a scene, no more and no less! I am not sure why that happened so often to me, but the case is I wouldn’t notice until it was too late, and the effect could be, as in this case, a bit awkward. So I decided to bring back the third horse and to delete one of the mongooses…
Good intentions but not enough time: out went the mongoose but I literally didn’t have the time to do the horse, even though, having no head, it would have been simpler to paint!
That mad race to finish such a big collection of oil paintings in record time left me so exhausted that, for better or worse, it was the start of my digital epoch. The easel still seems to look at me regretfully from the closet where it has rested for more than a decade. Only time will tell if I can take it out in a more relaxed, leisurely time. I can´t say now.

Here is the final painting as it appeared in “Prehistoric Mammals”

Color Sketches from Down Under

Here is just another example of a complex reconstruction which I had to paint in oils in record time and which required a lightning-fast color sketch to establish the palette I would use. This was also part of the “National Geographic Prehistoric Mammals” book, a project where I had little room for hesitation in terms of my compositions.

My preliminary pencil sketch defined anatomy, action and composition rather precisely, but I still needed to visualize the atmosphere

I had in mind an open environment as indicated in descriptions of the late Pleistocene of Australia where the fossils of the marsupial “lion” (Thylacoleo) and giant kangaroo (Sthenurus) were found.

This oil sketch only has some 15 cm in length and the fabric of the canvas shows quite clearly. I spent about an hour working on it and I quickly defined the warm, earthy colors of the terrain and dry vegetation and the sharp blue sky

While preparing the final painting shown here, I decided to make some changes relative to the color sketch. I included some thorny, dry bushes, and I changed the color of the sky to a more silvery hue with more sharply defined clouds.

As in other cases, the color sketch made me feel comfortable about the whole palette of the painting, and such last minute changes as I did felt more like calculated risks than blind turns.