Pierolapithecus: The Catalonian Ape

File:Pierolapithecus catalaunicus (Kopie).jpg
A replica of the fossilized skull of Pierolapithecus catalaunicus
Image Credit: Nasobema lyricum, https://commons.wikimedia.org/wiki/File:Pierolapithecus_catalaunicus_(Kopie).jpg

In terms of Mammalian evolution, the great apes (or “Hominidae”) are a recent development. They first appeared around 13-15 million years ago in the Miocene period and would go on to diversify into a variety of different species. Among these are, of course, the various species of human, including the only surviving one, our own (Homo sapiens). This one member of the great ape lineage now has a population of roughly 7 billion, lives across the entire globe, and has changed the landscape of the earth to such an extent that many geologists think that this modern age is its own distinct geological period (known as the Anthropocene). But to understand the earliest evolution of the great apes (and by extension our own species) studies must be made of the often fragmentary remains of these first apes. One such ape was discovered in 2004 in the Catalonia region of Spain. This species is Pierolapithecus catalaunicus.

The name Pierolapithecus catalaunicus comes from the village where the first fossils were discovered: “Els Hostalets de Pierola”. These first finds consisted of cranial (the top of the skull) and postcranial (the back of the skull) elements as well as some isolated teeth. Moving down, further remains were found of the thorax (chest and pelvis), lumbar region (the lower spine near the hips) and the wrist. Reconstructions from these remains estimate that it wouldve weighed around 55 kilograms, around the same as a female chimp. Studying these bones and further finds gave paleontologists clues as to how Pierolapithecus may have lived. For example, the structure of the wrist, thorax and lumbar bones suggests that Pierolapithecus would have spent most of its life in the trees, rather like the modern-day Orangutan.

Pierolapithecus is hypothesized to be a basal (or early) member of the great apes, but while it can be identified as one (e.g. it shared the same facial pattern as modern great apes, with a particularly Gorilla like face), it had yet to evolve all of their features (e.g. their fingers are not like great apes). Think of it as a kind of transitional form, or to use the overused (and misleading) term “missing link”, between the great apes and the “lesser apes” (i.e. Gibbons and Siamangs). Dating of the sediments around the bones indicate that they were roughly 12.5-11.9 million years old, putting Pierolapithecus in the middle of the Miocene period and suggesting that it was one of the oldest of the great apes. These bones also possess marks made by carnivores, indicating that they were either scavenged, or that there were active predators that Pierolapithecus had to watch out for.

Another feature that links Pierolapithecus to great apes is that it is thought to have had orthogrady. This term describes an animal that walks upright on its hind legs, with its spine curved partly upright, for long periods of time. Further, Pierolapithecus’ patella bone (a bone found on the upper knee) is like modern great apes and allows mobile movement of the knee. Combined with its moderately sized hands and a broad and shallow thorax, it suggests that Pierolapithecus was adapted more for vertical climbing and movement rather than suspending and couldn’t swing between branches. This is certainly weird considering that some modern great apes, like Chimpanzees, can swing. Therefore the ability to swing between branches must have evolved multiple separate times in great apes, and isn’t an ancestral trait. Another implication is that if a mostly tree dwelling animal possessed orthogrady then maybe upright walking didn’t originate just for walking on the ground. Instead orthogrady would have been used for walking along the branches of trees first before later being co-opted for a terrestrial lifestyle in humans their closest ancestors. One advantage of this is that it would have freed up Pierolapithecus’ arms to reach and grab ripe fruit and leaves that were previously out of reach.

But where on the great ape family tree was Pierolapithecus? well it is debated whether it is a basal hominid (e.g. ancestral to all living great apes) or a basal hominin (e.g. ancestral to humans, chimps, bonobos and gorillas only). Evidence that supports it being a basal hominid include a study in 2012 (Pérez de los Ríos, Moyà-Solà & Alba 2012) that analysed areas of the skull including the pneumatic structures, nasal area and palate. This analysis showed that these features were intermediate between basal hominoids and pongines (the ape family that contains Orangutans), and therefore that Pierolapithecus was more hominid than hominin. This study seems to have put the hominid idea in the driving seat, but if Pierolapithecus were to be a basal hominin, and on the line that produced humans and their close relatives then this raises another interesting possibility. It is often thought that all early hominid and human evolution took place within Africa. Then human relatives, and humans themselves, migrated out of Africa and spread to new lands in Europe, Asia and (in the case of humans) the rest of the world. However, Pierolapithecus was discovered in the Catalonia region of Spain! If the early human ancestor that Pierolapithecus is closely related to also lived in Europe then early human ancestors must have migrated from Southern Europe into Africa, where they would then continue to evolve and produce multiple human species, and humans themselves. In short, our very earliest ancestors may have originated in Europe, not Africa! Of course, this is just a theory and further fossil evidence from other stem hominids is required to prove or disprove it. It is equally plausible that Pierolapithecus may be an outlier, a side branch of stem hominids that migrated from Africa into Southern Europe while the early human ancestor lived in Africa. It is also possible that the range of Pierolapithecus would have extended into Africa too, we just have only found their remains in Spain at the moment. We cannot be sure right now, but it is a fascinating possibility!

Pierolapithecus, this seemingly unassuming great ape from Spain, is certainly an intriguing primate and a key piece of unlocking the puzzle box that is figuring out how this great, and eventually world changing, lineage came to be.

A diagram indicating where Pierolapithecus is thought to currently lie in great ape evolution
Image Credit: Institut Català de Paleontology, https://www.flickr.com/photos/icp_mcrusafont/6776869406

References/Further Reading

Moyà-Solà et. al. 2004: the paper that first described Pierolapithecus catalaunicus

Moyà-Solà, S., et al. (2004). “Pierolapithecus catalaunicus, a New Middle Miocene Great Ape from Spain.” Science 306(5700): 1339-1344.

Crompton, Vereecke & Thorpe 2008: a paper that described locomotion and orthogrady/pronogrady movement among early stem hominids.

Crompton RH, Vereecke EE, Thorpe SK. Locomotion and posture from the common hominoid ancestor to fully modern hominins, with special reference to the last common panin/hominin ancestor. J Anat. 2008 Apr;212(4):501-43. doi: 10.1111/j.1469-7580.2008.00870.x. Erratum in: J Anat. 2008 May;212(5):703. PMID: 18380868; PMCID: PMC2409101.

Hammond et. al. 2013 paper, published in the Journal of Human Evolution, on the pelvic morphology of Pierolapithecus and comparisons with other stem hominids

Ashley S. Hammond, David M. Alba, Sergio Almécija, Salvador Moyà-Solà, Middle Miocene Pierolapithecus provides a first glimpse into early hominid pelvic morphology, Journal of Human Evolution, Volume 64, Issue 6, 2013, Pages 658-666, ISSN 0047-2484, https://doi.org/10.1016/j.jhevol.2013.03.002.

Nakatsukasa 2019 paper on the spinal morphology of Miocene apes like Pierolapithecus and the evolution of Orthogrady

Nakatsukasa M. (2019) Miocene Ape Spinal Morphology: The Evolution of Orthogrady. In: Been E., Gómez-Olivencia A., Ann Kramer P. (eds) Spinal Evolution. Springer, Cham. https://doi.org/10.1007/978-3-030-19349-2_5

Pina et. Al. 2014 paper on the structure of Pierolapithecus’ knee bones in relation to its skeleton, and what can be inferred about its climbing and swinging ability

Pina M, Almécija S, Alba DM, O’Neill MC, Moyà-Solà S (2014) The Middle Miocene Ape Pierolapithecus catalaunicus Exhibits Extant Great Ape-Like Morphometric Affinities on Its Patella: Inferences on Knee Function and Evolution. PLoS ONE 9(3): e91944. https://doi.org/10.1371/journal.pone.0091944

• Pérez de los Ríos, Moyà-Solà & Alba 2012 paper that examined the skull areas containing the nasal region, pneumatic structures and palate. Their study provides evidence that Pierolapithecus is a basal hominid.

Miriam Pérez de los Ríos, Salvador Moyà-Solà, David M. Alba, The nasal and paranasal architecture of the Middle Miocene ape Pierolapithecus catalaunicus (primates: Hominidae): Phylogenetic implications, Journal of Human Evolution, Volume 63, Issue 3, 2012, Pages 497-506, ISSN 0047-2484, https://doi.org/10.1016/j.jhevol.2012.05.012.

Daeodon the Terminator

How the Terminator Pig is thought to have looked like!
Image Credit: Max Bellomio, https://commons.m.wikimedia.org/wiki/File:Daeodon_shoshonensis_.png

Daeodon is an animal that has had a lot of rather intimidating nicknames associated with it over the years. These have ranged from the “Terminator Pig” (which makes me think of a pig wearing sunglasses and travelling through time on a mission to destroy!) to the “Hell Pig” (which suggests a giant boar rising from a fiery pit accompanied by heavy metal!). Even its name “Daeodon” translates as “Dreadful Teeth”, a name that would strike fear into the hearts of dentists everywhere. But what was Daeodon really like? And did it deserve its reputation?

Daeodon belonged to a now extinct branch of the “artiodactyls”, a mammal group that also contains pigs, horses and even whales, known as the Entelodontidae, or “Entelodonts”. In life Entelodonts would have looked superficially pig-like with a long snout, hooved feet, tall shoulder hump, short tail and a round body. The “terminator” and “hell” parts of its nicknames stem from its huge size, Daeodon was the size of a bison, and it’s grotesque looking face which possessed side flanges, bony bumps and fearsome looking teeth. However despite appearances the Entelodonts’ closest relatives are not actually pigs. A study published in 2009 by Michael Spaulding, Maureen O’Leary and John Gatesy found that, whilst studying the ancestry of the artiodactyl group, they were more closely related to the whippomorpha subgroup (which contains hippos, whales and dolphins) than modern pigs. This has changed some reconstructions of entelodonts into a more bulky animal than previously thought, more akin to a land-based hippo than an oversized pig. So maybe the famous nickname of “terminator pig” should now be “terminator hippo”, which is just as horrifying considering how aggressive and dangerous modern hippos are! Entelodonts were a very successful group of mammals. First evolving in Mongolia roughly 40 million years ago during the Eocene they diversified into multiple different species that spread into Europe and North America during the Oligocene and Miocene. Daeodon was in many ways the culmination of this line, being not only the largest entelodont but also one of the last.

The skull of Daeodon showing its strong build and differentiated teeth.
Image Credit: Matt Celeskey, https://commons.m.wikimedia.org/wiki/File:Daeodon_skull.jpg

Roaming the plains of North America from 25-18 million years ago, Daeodon lived alongside a weird menagerie of life consisting of animals both familiar and unfamiliar. Alongside the ancestors of today’s horses and camels were extinct animals like the Chalicotheres, relatives of horses that walked on their knuckles like gorillas and possessed large claws that they used to pull down vegetation, and Hyaenodonts, mammalian carnivores that belonged to the now extinct Creodont group. Standing 1.8 metres tall and weighing roughly half a tonne Daeodon would have been an imposing animal in this environment. The distinctive flanges on its 3 ft. long head covered large cheek bones and were anchor points for large jaw and neck muscles, giving it a very powerful bite. Despite its fearsome appearance however, Daeodon was an omnivore. It possessed differentiated teeth just like in humans; gripping incisors at the front, large canines in the middle and crushing molars at the back. This enabled it to eat almost anything it came across including roots and tubers, fruit, leaves and meat. It would have been a very effective scavenger as a highly developed sense of smell would allow it to locate a carcass accurately from a distance, tracking the smell in a zig-zagging fashion. Furthermore its large size would have enabled it to drive off other animals from the kill. Make no mistake however, Daeodon would have dabbled with hunting live prey as well. It is thought to have been an ambush hunter, using its large size and powerful jaws to overpower and crunch through prey. But it’s not just other animals that Daeodon would have fought. Puncture marks found on the skulls of other entelodont species have shown that they fought each other, whether for mates, territory or both. So in many ways, given its large size and omnivorous lifestyle, Daeodon might have had a similar lifestyle to a modern day Grizzly Bear. Sadly this magnificent beast isn’t around today to give Grizzly Bears a contest. The last Daeodon went extinct around 18 million years ago. This coincided with the first emergence in North America of the large Bear-Dog Amphicyon (see my Amphicyon blog for more!), which had migrated from Asia. This predator, while smaller, was swifter and most importantly; more intelligent. As a result it seems to have partly out-competed Daeodon. Combining this with a climate which was becoming drier as the Miocene progressed resulted in Daeodon being driven to extinction, leaving only their fossils as remnants of a once widespread group.

Speaking of these fossils, the first Daeodon fossils were discovered in 1879 by the American fossil collector Edward Drinker Cope. Cope is a big name in the field of palaeontology, being responsible for the discovery of many extinct species such as the sauropod dinosaur Camarasaurus and the sail backed stem-mammal Dimetrodon. He is also known for his bitter rivalry with fellow American fossil hunter Othniel Charles Marsh. The two were locked in a race to discover and describe the most new species in a rivalry that has been termed “The Bone Wars”. When Cope examined Daeodon he determined it to be a member of the perissiodactyls, a group of mammals that contain modern day Zebras and Rhinos. It was only in 1909 when it was found that this wasn’t the case and it was actually an artiodactyl. For a long time Daeodon wasn’t the most widely known entelodont, with Dinohyus (meaning “terrible pig”) taking that title. However later it was found that Dinohyus and Daeodon, and another entelodont named Ammodon were actually one and the same animal. Because the rules of species dictate that the first name given to a species is the one that is kept Daeodon was the winner out of the three, with Dinohyus and Ammodon becoming synonyms.

A skeletal of Daeodon, showing how the bones all fit together and how big the animal was compared to a human.
Image Credit: bLAZZE92, https://blazze92.deviantart.com/art/Daeodon-shoshonensis-419367474

Entelodonts were a bizarre group of mammals, with Daeodon being the most eye-catching and iconic of them all. It dominated the North American landscape and while its size and power certainly earns it the “Terminator Pig” nickname (minus the pig part of course) that was only one side to it. As well as being a big and intimidating hunter and fighting for what it wanted, Daeodon would have eaten its greens, rolled happily in the mud and napped peacefully in the sun!

References/Further Reading

Spaulding, O’Leary and Gatesy 2009 paper on the family tree of artiodactyls, including who Entelodonts are most closely related to

Spaulding, Michelle et al. “Relationships of Cetacea (Artiodactyla) among mammals: increased taxon sampling alters interpretations of key fossils and character evolution.” PloS one vol. 4,9 e7062. 23 Sep. 2009, doi:10.1371/journal.pone.0007062

Joeckel 1990 paper on entelodont paleoecology and jaw function

Joeckel, R. (1990). A functional interpretation of the masticatory system and paleoecology of entelodonts. Paleobiology, 16(4), 459-482. doi:10.1017/S0094837300010198

A blog, written by Joe Sawchak and published on the Carnegie Museum of Natural History website, about a life size model of Dinohyus named “hyus”. This model was characterised by the weirdly human eyes!

Sawchak, Joe, “Dinohyus: “Terrible Pig” in more ways than one”, Carnegie Museum of Natural History, carnegiemnh.org/dinohyus-terrible-pig-in-more-ways-than-one/

An article, written by Vasika Udurawane and published on Earth Archives, about the rise of the “Terminator Pigs”

Udurawane, Vasika, “Terminator pigs: Rise of the entelodonts”, Earth Archives, 2016, eartharchives.org/articles/terminator-pigs-rise-of-the-entelodonts/

Bear + Dog = Amphicyon

Image result for amphicyon
Reconstruction of Amphicyon ingens: The largest of the Bear-Dogs
Image Credit: roman uchytel, https://ru.wikipedia.org/wiki/%D0%A4%D0%B0%D0%B9%D0%BB:Amphicyon-ingens_reconstruction.jpg

16-18 million years ago, a fierce predator roamed the North American landscape. It had a long snout and a long tail like a modern day wolf, but it also had a stocky build, powerful forelimbs, plantigrade feet (i.e. it walked with its paws flat on the ground) and grew up to 2.5 metres long and 1.5 metres tall. These latter characteristics are much more like a modern bear. This was a weird mix of features. Anybody seeing this animal today, not knowing what it was, would think to themselves; “Is that a mutated bear?” “Or is it a new dog breed?”. This animal has the scientific name Amphicyon, meaning “Ambiguous dog”, however its common nickname is “Bear-Dog”. This is fitting because Amphicyon looks like an animal that would be the result of bizarre genetic cross-breeding of a Labrador and a Grizzly Bear! So the question that I will ask in this blog is, what in the world was it?

The genus Amphicyon (genus being a group of species, i.e. like the big cat group) was a very successful animal in its time, with multiple species stretching across the globe from North America to Europe to Africa. These species included Amphicyon longirams, which stalked what is now Florida, and Amphicyon Ingens; which reached a size comparable to the largest terrestrial carnivore alive today – the Polar Bear. In 2016 there was even a Chinese species discovered which was named Amphicyon zhanxiangi. Amphicyon first evolved in Europe and Asia, before migrating into North America during the mid-Miocene period 18 Million years ago. From this period they out-competed the resident mammalian carnivores such as the Hyaenodonts (large mammalian predators with shearing teeth), the Entelodonts (who have the awesome nickname of “Terminator Pigs”) and other Bear-Dogs to become the top dog (pun intended) of the Miocene landscape.

A map showing the geographical range of Amphicyon. As you can see Europe, Asia, North America and Africa all had their own Amphicyon species!
Image Credit: Noles1984, https://en.m.wikipedia.org/wiki/File:Amphicyon_range.png

Bear-Dogs as a whole are thought to have had a variety of hunting strategies that varied between species. Amphicyon, being larger and more stocky in build, would have hunted somewhat like a bear; surprising their prey and pursuing it for a short distance before using their muscular forelimbs and large body size to pin it down before biting at the neck and body to finish it off. Being an ambush hunter it wouldn’t have regularly partaken in long chases, though it was able to pursue prey for longer than other ambush predators. Their size would have allowed them to hunt larger mammalian herbivores, which would have included early rhinos. We know this from a fossil unearthed from Portugal of the lower jaw of the extinct rhino Iberotherium. This jaw has clear puncture marks in it made by the teeth of a large carnivore. A study, conducted by Antunes, Balbino and Ginsberg in 2006, concluded that the culprit was Amphicyon giganteus as it was the only known carnivore from the same time and place large enough to inflict these type of wounds (though whether it did so when hunting or scavenging this Iberotherium is unknown). Meanwhile other species of Bear-Dogs, such as Borocyon, had longer legs and more slender bodies. This suggests that they hunted more like modern day wolves; pursuing their prey over long distances. While Amphicyons diet would have mostly consisted of meat it is thought that other Bear-Dogs might also have been omnivorous to a degree, eating plant matter and berries to supplement their diet. It is also thought that they, along with other Bear-Dogs, exhibited denning behaviour, digging out burrows in which they could raise their young and take shelter. Like all mammals they would have exhibited high levels of parental care, raising pups until they were old enough to fend for themselves. Amphicyon also exhibited sexual dimorphism, just like bears, with the males being substantially larger than the females.

A mural depicting a scene from the 16-13 million year old Mascall assemblage in Oregon, USA, showing an Amphicyon hunting a Miolabis.
Image Credit: National Park Service, https://www.nps.gov/joda/learn/nature/mascall.htm

So to answer the question posed at the beginning of this blog, what exactly was Amphicyon? A bear or a dog? Well the answer is in fact neither. Amphicyon belonged to a family known as the Amphicyonidae, which included it and all other species of Bear-Dogs. This family belonged to an order known as the Caniformia, which also contains the dog and bear families as well as foxes and sea lions. As a result Amphicyon and its kin were actually close cousins of bears and dogs, separating from them in the evolutionary tree around 40 million years ago during the Eocene period. The Bear-Dogs evolved into a wide range of shapes and sizes, filling a variety of niches. However, despite its success, Amphicyon and its kin would sadly go extinct around 7.2 million years ago. The main cause of this was the changing environment at the end of the Miocene. The climate became dryer, which resulted in the emergence of more open plains. This meant that the slower, bulkier Amphicyon could not find the cover it needed to ambush its prey. This meant that they struggled to find enough food to support their large size. Also (rather ironically) another factor was the emergence and success of the dogs and bears. Dogs were more specialised in the endurance hunting style that is effective on open plains, and some had jaws that could crush bone, something Amphicyon couldn’t do despite its impressive appearance! (In fact one group of dogs, named the Borophaginae, are commonly referred to as the “bone-crushing dogs”!) Bears meanwhile had a more omnivorous diet than Amphicyon, giving them access to a wider range of food. Dogs and Bears were also generally smaller, so didn’t require as much food to keep them alive. In addition at about this time the first Sabre-Tooth Cats were evolving, bringing yet more competition. These three groups together took over all the niches that had previously been occupied by Amphicyon and its relatives. As a result this magnificent group of animals were squeezed out and confined to the pages of pre-history.

It’s a shame too, as a pet Amphicyon would have been not only a cute puppy but also grown to be an effective “guard dog”. It would certainly draw more than a few glances when you took it for a walk!

References/Further Reading

Antunes, Balbino & Ginsberg 2006 paper on Iberotherium jaw fossil showing bite marks made by Amphicyon

Antunes, Miguel. Telles, Balbino, Ausenda C., Ginsberg, Léonard. Ichnological evidence of a Miocene rhinoceros bitten by a bear-dog (Amphicyon giganteus), Annales de Paléontologie, Volume 92, Issue 1, 2006, Pages 31-39,

Florida Museum information page on Amphicyon longirams

Morse, Paul E. “Amphicyon longiramus” Florida Museum, Oct. 5, 2012, floridamuseum.ufl.edu/florida-vertebrate-fossils/species/amphicyon-longiramus/

Sorkin 2006 paper on Amphicyon and Ischyrocyon diet and hunting behaviour

Sorkin, Boris. (2006). Ecomorphology of the giant bear-dogs Amphicyon and Ischyrocyon. Historical Biology. 18. 10.1080/08912960600618073.

Jiangzuo et. al. 2016 paper describing the Amphicyon zhanxiangi

Qigao Jiangzuo, Chunxiao Li, Shiqi Wang & Danhui Sun (2018) Amphicyon zhanxiangi, sp. nov., a new amphicyonid (Mammalia, Carnivora) from northern China, Journal of Vertebrate Paleontology, 38:6, DOI: 10.1080/02724634.2018.1539857