Diminishing giants

Island dwarfism is perhaps one of the most beautiful examples of evolution through natural selection. Large animals that arrive on an island, evolve smaller sizes to survive on less food, and because there are fewer (if any) predators. (Similarly, small animals that are isolated on islands can get bigger, as we’ve seen with the dodo, the giant rabbit, and the giant duck.) The way species interact and are limited in island environments, is known as the island syndrome. This is where the form of a species along with the surrounding ecosystems, all play a part in how, and if, it survives with less resources available and new conditions to live in.

It does happen. And we have seen it already with many different species. The cute little hippos in the Mediterranean, tiny mammoths off the coast of California, and a weird goat from Mallorca, are just a few examples we have written about. These animals, and many more, adapted to island life, some in the most peculiar way. Isolated from populations on the mainland, they evolved in their own way to survive in a smaller space with new habitats and foods. It’s something quite remarkable when you think about it. Enormous mammoths evolving to a much smaller size over a few generations. Evolution is a pretty funky beast.

Another of these unique island creatures was the Cebu tamaraw, the extinct dwarf water buffalo (Bubalus cebuensis). Fossils of this small extinct water buffalo were discovered on the island of Cebu in the Philippines, in the 1950s, and it wasn’t for another 40 years that they were actually studied. This little creature patiently lay waiting in a museum. And Cebu tamaraw was small. Like, really small.  Buffalo are very big animals, and can be eye to eye with an adult human. Cebu tamaraw went through extreme size reduction, from a big buffalo to an animal about the size of an Alsatian! It’s the smallest example (so far) of island dwarfism in bovids.

Sometime, around 100,00 years ago the sea levels in the Philippines were much lower than today. Which meant that the hundreds of islands that we see in the Philippines today were either linked, or the water between them was much less. This is important, because this lower sea level allowed many animals from the mainland to wander, and sometimes take a short paddle to many of the islands. We do not have lots of information about when the Cebu tamaraw first evolved, because we have so few fossils found. They evolved from the Asian water buffalo, probably sometime around 100,000 years ago when the islands were more accessible. Similarly, we don’t know when they became extinct. Some researchers suggest this may have been relatively recently, just a few thousand years ago. And it is very likely that humans saw these miniature buffalos.

Today, around 170 species of mammals live in the Philippines, making it one of the richest places for mammals in the world. The huge number of islands just off the mainland, along with the changing sea levels, allowed many species of mammals to make their way to new environments and evolve separately from their mainland relatives. In all of this beautiful biodiversity is one close relative of the Cebu tamaraw, the tamaraw (Bubalus mindorensis). Slightly larger than it’s extinct relative, around the size of a sheep, the tamaraw is another dwarf water buffalo living on the island of Mindoro. It is currently endangered, with fewer than 450 individuals left, due to human habitat destruction and hunting.

We can learn a little about our extinct beast by looking at the life of the tamaraw that’s still alive today. They and once lived all across the island, from the coast to the top of the mountains, showing they were well adapted to live in a range of environments. With no predators (before humans arrived), the tamaraw was active in the day time, feeding on grasses and bamboo shoots. Today they are more restricted to thicker bushy vegetation and are active at night, which is a recent move by them to avoid humans. More fossils of the Cebu tamaraw from these islands will tell us al lot more about this enigmatic species, and how similar it was to it’s living relative.

More fossils will also reveal how diverse life was on these islands in the Philippenes. As recently as 2017, another species of dwarf buffalo was discovered to the south on the island of Sulawesi, in Indonesia. This long stretch of islands are not only rich in biodiversity today, but have been in the past. Full of amazing animals, and the more we discover, the more we can learn more about the richness of life on Earth.

Witten by Jan Freedman (@JanFreedman)

Further reading:

Croft, D. A. L., et al. 2006. Fossil remains of a new diminutive Bulbalus (Artiodactyla: Dovidae, Bovini) from Cebu island, Philippines. Journal of Mammalogy. 87. pp.1037-1051. [Full article]

Lomolino, M. V., et al. 2013. Of mice and mammoths: generality and antiquity of the island rule. Journal of Biogeography. 40. pp.1427-1439. [Full article]

Rozzi, R. 2017. A new extinct dwarfed buffalo from Sulawesi and the evolution of the subgenus Anoa: An interdisciplinary perspective. Quaternary Science Reviews. 157. pp.188-205. [Full article]

Rozzi, R., et al. 2020. Casual explanations for the evolution of ‘low gear’ locomotion in insular ruminants. Journal of Biogeography. DOI: 10:111/JBI.13942. [Full article] van der Geer, A., Lyras, G., and Drinia, H. 2013. Trends of body size evolution in the fossil record of insular Southeast Asia. Sage 2013. U

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Foolish dogs

In 1870 another species was wiped off the face of the Earth. The warrah, or the Falkland Islands wolf, was only known to science in 1792. Less than 100 years later it was gone. The last known induvial died in a zoo.

The first human settlement to the Falklands was in 1764, and has passed from French, to Spanish to British, to American control over the years. It was these early years that was the end of the only mammal on the Falklands. It’s scientific name, Dusicyon australis, literally means ‘the foolish dog of the south’. It was tame. It hadn’t seen humans before, so had no need to fear them. But this was disastrous. Sailors, and later settlers, would kill the warrah for meat and fur, and it wasn’t long before their numbers shrank.

The Falkland Islands wolf, Dusicyon australis. (Art John Gerrard Keulemans. Public Domain)

Charles Darwin visited the Falklands in 1834, and as always, made detailed observations of this usual animal. It was constrained to the Falklands, found nowhere else in South America. He notes how people would kill them easily “by holding a piece of meat in one hand, and in the other a knife ready to stick them.” And he foresaw their extinction: “Their numbers have rapidly decreased; they are already banished from that half of the island which lies to the eastward of the neck of land between St Salvador Bay and Berkeley Sound. Within a very few years after these islands shall have become regularly settled, in all probability this fox will be classed with the dodo.”

We don’t know how the warrah arrived on the Falklands, which is 300 miles from the South American mainland. But we do know that its ancestor, Dusicyon avus lived in South America.

Dusicyon avus were widespread across South America and fossils have been found in Brazil, Uruguay, Argentina, Chile, and Patagonia. Although called a wolf because of the Falkland Islands wolf, both species are actually closer to foxes than to wolves. DNA research into the fossils of D. avus showed it to be closely related to the odd, leggy, Manned Wolf (which again the name is misleading, as it is neither a wolf nor a fox!).

About the size of a small Alsatian, D. avus were very common in the Late Pleistocene and Holocene. We can find out a lot about how they would have lived by looking at their bones. Analysis of the skull shape suggests that they may have filled the same ecological niche as jackals do today.  It was likely a scavenger, whilst hunting smaller prey. We don’t know if they shared a similar life to jackals, which live as monogamous pairs, or more like large family packs similar to wild dogs. With shorter legs than wild dogs, it is more likely they were not long-distance runners chasing prey down. But they were very successful, and ranged over most of grass plains of South America, which makes their extinction very strange.

The small fox wolf, Dusicyon avus from South America.

It was thought that they became extinct around 3000 years ago, which is late in comparison to other extinctions in South America (between 12,000 and 10,000 years ago). Recent radiocarbon dating suggests they became extinct as recently as 400 years ago. This is extremely recent. And quite sudden. Some researchers have suggested that a more humid climate may have changed the available prey for D. avus, but these were more likely to be opportunistic predators, so it seems very unlikely. They lived in open grass environments, across varying climates, so a change in humidity wouldn’t have affected them much. Humans did have a relationship with these animals. Several burial sites contain bones of D. avus, with at least one potentially being intentionally buried: suggesting that it was a tamed animal (people have tamed wild foxes across the world for centuries). Their disappearance does coincide with Europeans settling in the Americas, and domestic dogs, and increased human presence could have just added that extra pressure.

This isn’t a well-known beast. Giant sloths and sabre tooth cats get a lot of the attention when it comes to Pleistocene animals from South America. But this little fox-wolf was a part of their ecosystem too. And they shouldn’t be forgotten. There are some who, like the thylacine, believe that D. avus is still out there. Sadly, I don’t think so. Sadly, these wonderful little animals are one in a long list which are gone from our beautiful planet forever.

Written by Jan Freedman (@JanFreedman)

Further reading:

Austin, J. J., et al. 2013. The origins of the enigmatic Falkland Islands wolf. Nature Communications. 4 (1552). [Full article]

Hamley, K M., et al. 2021. Evidence of prehistoric human activity in the Falkland Islands. Science Advances. 7 (44). [Full article]

Prates, L. 2015. Crossing the boundary between humans and animals: the extinct fox Dusicyon avus from hunter-gatherer mortuary context in Patagonia (Argentina). Antiquity. 88 (342). pp.1201-1212. [Abstract only]

Meloro, C., et al. 2017. Evolutionary ecomorphology of the Falkland Island wolf Dusicyon austalis. Mammal Review. [Abstract only]

Prevosti, F. J., and Martin, F. M. 2013. Paleoecology of the mammalian predator guild of Southern Patagonia during the latest Pleistocene: Ecomorphology, stable isotopes and taphonomy. Quaternary International. 305. pp.74-84. [Abstract only]

Prevosti, F. J., et al. 2015. Extinctions in near time: new radiocarbon dates point to a very recent disappearance of the South American fox, Dusicyon avus (Carnivora: Canidae). Journal of the Linnean Society. 116 (3). pp.704-720. [Full article]

Slater, G. J. 2009. Evolutionary history of the Falklands wolf. Current Biology. 19. pp.937–938. [Full article]

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When time disappears

Time. It’s a funny thing. We are aware of time. We watch time. Sat on a long train journey, or in a very tedious meeting, and time seems to last for ever: the seconds tick by slowly. There are other moments when time just seems to vanish. An afternoon with your little ones can be over in an instant. Hours spent with the one you love can seem like minutes. That’s the strange thing about time. It can warp. It can appear longer or shorter even though the same amount of time has passed. I guess you can measure your enjoyment of something through the passing of time.

For me there are a couple of things that make time just vanish. One is being out in nature. Away from emails, away from people. Watching the insects trundle or hover is like being transported to a different world. Sitting watching little blue tits or goldcrests dart back and forth is exhilarating. And I could sit and watch a heron on a river bank all day long. Here, nothing else exists, not even time. It is just myself and the beautiful world.

The gorgeous Grey Heron (Ardea cinera). (Photo Andreas Trepte. Public Domain)

Herons are gorgeous birds, and so wonderful to see. Their long stilt-like legs moving ever so slowly to get in the best position. And once in position, it waits. Not a sound. Not a movement. The legs don’t even twitch. And then you see it’s body slowly move forwards and down. The long neck arched back and poised. Ready. And you sit up and watch intensely. The heron strikes so fast it makes you gasp. It lifts its head with a fish, or a frog. It’s quite something to witness. Watching these birds is just mesmerizingly beautiful.

The heron that hypnotises me, is the Grey Heron (Ardea cinerea), a common sighting along rivers, estuaries and lakes in the UK. They are fairly big birds too, up to a meter tall. But they are not the tallest. The Goliath Heron (great name!), is over a meter and a half tall, as tall as many adults. Even this giant wasn’t the largest heron to have stalked the shallows. The enormous Bennu Heron (Ardea bennuides) reached over two meters tall, and would have been able to look a human in the eye.

The huge Bennu Heron next to a 1.8m tall human.

The Bennu Heron is an enigmatic bird. Fossils are only known from the Umm Al-Nar excavations, near Abu Dhabi, in the United Arab Emirates. This site dates to the Bronze Age (around 4,500 years ago) and excavations revealed human remains and artefacts, along with several animals species, including the first evidence of domesticated camels, and the giant Bennu Heron. It’s an important archaeological site, and was the first site to be excavated in the United Arab Emirates, just 50 years ago. Several new sites discovered over the following decades showed that the Umm Al-Nar culture was fairly widespread along the coast and inland around 4,500 years ago.

Umm Al-Nar was a well established settlement for several hundred years, with a large number of houses, some of which were big enough for congregations of people inside. The site also has around 49 cairns, or tombs; stones stacked into dome-like shapes. Human remains and animal bones have been found inside these tombs, as well as well-preserved fragile pottery vessels, still with the painted decorations on them. This wasn’t just a little village. The people here were trading with other settlements around the United Arab Emirates, and even further afield.

How does our giant heron fit in to this amazing site? Large numbers of animal bones were excavated near the houses, including camels, dugongs, turtles, and several bird species, including the Bennu Heron. There is no evidence that the heron was eaten by the villagers: no cut marks, no burns on the bones. It is more than likely that they are the remains of birds which died naturally, and accumulated with other species.

Today Umm Al-Nar is connected to the mainland due to dredging and land reclamation. 4,500 years ago, however, it was a small island, surrounded by shallow waters and marshlands. This was the environment for the Bennu Heron. Those long legs perfect for silently wading through the shallows. Herons today will eat anything including fish, small mammals, reptiles and amphibians. They are not picky. The Bennu Heron was probably similar, a large predator, still, motionless, waiting and grabbing any unfortunate animal it could.

The Bennu Heron may have been more widespread than just Arabia. Bennu was god in Ancient Egypt linked to the sun and rebirth. This god was a giant heron. Ancient Egyptian writings show this god to be the same size as the Bennu Heron found at Umm Al-Nar. And we do know that the Ancient Egyptians based their gods on animals they saw around them. Some archaeologists and historians think that the Bennu Heron was the inspiration of Bennu the god (the name Bennu Heron was given to it because of it’s similarity with the Bennu deity).

Ancient Egyptian drawing on papyrus of the Bunnu God. (Image Public Domain)

More fossils will help us to understand this animal much better. We don’t currently know how long this gigantic bird was on Earth for, or when it became extinct, or even why. We don’t know whether they nested in trees (like some heron species do today). There’s an awful lot we don’t know. But we do that humans did see it. Perhaps they too sat and watched the Bennu Heron. Maybe they lost all track of time as they watched this colossal beauty in the marshlands hunting for food.

Written by Jan Freedman (@JanFreedman)

Further reading:

Al Tikriti, W. Y. Umm An-nar, an ancient capital of Abu Dhabi: distribution of a culture and the current state of the site. In Fifty Years of Emirates Archaeology. Chapter 8. Motivate Publishing. [Full article]

Hellyer, P. 1998. The relevance to Archaeology to coastal zone management. Tribulus. 8 (1). pp.26-28. [Full article]

Hoch, E. 1977. Reflections on prehistoric life at Umm An-Nar (Trucial Oman) based on faunal remains from the third millennium BC. In M. Taddei (Ed). South Asian Archaeology 1977. Fourth International Conference of the Association of South Asian Archaeologists in Western Europe. pp.589-638.

Krienitz, L. 2018. The firebird Phoenix. In Lesser Flamingos. Springer, Berlin, Heidelberg. [Abstract ony]

Potts, D. T. 2001. Before the Emirates: and archaeological and historical account of developments in the region c. 5000BC to 676 AD. In Al Abed, I., & Hellyer, P. (Eds). The United Arab Emirates: A new Perspective. London, Trident Press. [Full article]

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The bellowing antelope

Locked within Rusinga Island are secrets from the past. Secrets of life long gone trapped in the ash of an ancient volcano. It is sat in the north east of Africa’s largest lake known by locals as Nam Lolwe, Nnalubaale, and Nyanza, and was called Lake Victoria by the British in 1858. Fossils on Rusinga Island have been known by locals for many centuries, including the remains of extinct crocodiles, antelopes, and ancient primates.

A gold prospector discovered the first primate fossil, a small jaw bone, on the island in 1909. But it wasn’t until expeditions in the 1930s and 1940s by Louis and Mary Leakey and their team that put this and other fossils on the world stage. Louis and colleagues found several teeth and bones from primates in the 1930s, which they named Proconsul. In 1948, Mary found the first fossil skull of this ancient ape. Originally seen as an ancient link between humans and apes, the media around the world flocked to see this beautiful specimen, which set up the Leakeys for lots of generous funding opportunities for the future.

Illustration of Proconsul. (Art by Maurico Anton. Public Domain)

Today there are four known species of Proconsul, which lived between 23 and 14 million years ago. It was not an ape-human ancestor, or the ancestor of chimpanzees, as was once thought. Lacking a tail, Proconsul may be one of the earliest ancestors of apes, or it may just be an evolutionary dead end, leaving no descendants.

It wasn’t just the ecosystem of 23 million years ago that Rusinga Island has revealed. Life in the Pleistocene, the time of the Twilight Beasts, was also preserved in younger rocks. Fossils of turtles, extinct antelopes (Damaliscus hypsodont), extinct pigs (Kolochoerus) and many other extinct species of bovids have been found. Including one very odd species, Rusingoryx atopocranion, the bellowing antelope.

The strange looking antelope Rusingoryx. It was slightly shorter than a human, and had one of the strangest mammal skulls known. (Illustration by Sophia Anderson. Reproduced with permission.)

Rusingoryx is a relative newcomer to the mélange of Pleistocene beasts. Found on a site, appropriately named Bovid Hill, the first fossils were named in 1984. It was almost 20 more years until more excavations found many more specimens, some of which showed signs of being butchered by humans. Closely related to the wildebeest, this animal was a much smaller antelope, with some peculiar features. (A quick side note on antelopes and bovids. Antelopes may be more familiar as those fast, springy, deer like animals seen on nature programmes. They are however a kind of catch-all name for animals in the Family Bovidae that are not cows, sheep, or goats. So wildebeests are called antelopes despite looking more like cows or bison, because of their anatomy. And our strange beast, Rusingoryx, is also an antelope.)

Although Rusingoryx has been found at other sites in Kenya, the abundance of fossils at Bovid Hill have given us a lot of information about this unusual bellowing beast. The skull, well the skull was weird. With a pointy nose, it has a feature not seen in any other mammal: a large empty nasal passage. The rest of the skeleton shows that this antelope was fast and well adapted to running in open landscapes to flee from predators.

So many individuals have been found at Bovid Hill, that they may have been from a single herd, which were all buried very quickly in a shallow river channel around 65,000 years ago. But this herd may not have died naturally. There are stone tools in the same deposits, and cut marks on the bones, showing that this may have been a kill site for Homo sapiens. How did humans kill such a large group of fast herbivores isn’t known, but it does show that they did hunt them and trap them, perhaps in water to slow them down.

In the past, Rusinga Island was not an island, but joined to the mainland of Kenya until the lake subsided over time, flooding more of the land until Rusinga was seperated. All these herds of different species were roaming and moving across the plains of Kenya. The adaptations of Rusingoryx and other species show that the plains of Kenya were open grasslands, different from the drier grasslands in Kenya today. This may be the reason for their extinction. These unique creatures were well adapted to the open plains, but their teeth were not adapted to drier grasses. Although they were hunted by humans, it may have been the changing environment that caused Rusingoryx to vanish.

A scan of the skull of Rusingoryx. The scan revealed that the nasal passage (coloured in yellow) and the sinuses (coloured in green) were completely empty and would have been filled with air. (Image from O’Brien, 2016)

And that weird nasal passage full of air? Well, it was quite bizarre and unlike anything seen for 80 million years. It was hollow, and some researchers suggest that it may have been used to make deep bellows, similar to hadrosaur dinosaurs. This is an example of convergent evolution, where two completely different species evolved similar traits independently. Just like hadrosaurs, Rusingoryx may have used their nasal dome for vocalisation to communicate in the herd, or to attract a mate. It would have been amazing to hear the low bellow of this beast on the plains of Kenya, and our species did. Sadly, they became extinct sometime around 10,000 years ago, so like the trumpeting dinosaurs, we can only imagine the sounds they made.   

Written by Jan Freedman (@JanFreedman)

Further reading

Bonnefille, R., Roeland, J.C., and Guiot, J. 1990. Temperature and rainfall estimates for the past 40,000 years in equatorial Africa. Nature 346. pp.347–349. [Abstract only]

Faith, J. T., et al. 2011. Taxonomic status and paleoecology of Rusingotyx atopocranion (Mammalia, Artiodactyla), and extinct Pleistocene bovice from Rusinga Island, Kenya. Quaternary Research. 75. 3. pp.697-707. [Abstract only]

Faith, J. T., et al. 2012. New perspectives on middle Pleistocene change in the large mammal faunas of East Africa: Damaliscus hypsodont sp. nov. (Mammalia Artiodactyla) from Lainyamok, Kenya. Palaeogeography, Palaeoclimatology, Palaeocology. 361-362. pp.84-93. [Full article]

Faith, J. T., et al. 2014. Biogeographic and Evolutionary implications of an extinct Late Pleistocene impala from the Lake Victoria Basin, Kenya. Journal of Mammal Evolution. 21. Pp.213-222. [Full article]

O’Brien, H. D., et al. 2016. Unexpected Convergent Evolution of Nasal Domes between Pleistocene Bovids and Cretaceous Hadrosaur Dinosaurs. Current Biology. [Full article]

Jenkins, K. E., et al. 2017. Evaluating the potential for tactical hunting in the MIDDLE Stone Age: Insights from a bonebed of the extinct bovid, Rusingoryx atopocranion. Journal of Human Evolution. 108. pp.72-91. [Full article]

Klein, R. G., and Cruz-Uribe, K. 1991. The bovids from Elandsfontein, South Africa, and their implications for the age, palaeoenvironment, and origins of the site. African Archaeological Review. 9. pp.21–79. [Full article]

Kovarovic, K., et al. 2021. Ecomorphology and ecology of the grassland specialist, Rusingoryx atopocranion (Artiodactyla: Bocidae), from the late Pleistocene of western Kenya. Quaternary Research. 101. pp.187-204. [Full article]

O’Brien, H. D., et al. 2016. Unexpected convergent evolution of nasal domes between Pleistocene bovids and Cretaceous hadrosaur dinosaurs. Current Biology. 26 (4). pp.503-508. [Full article]

Pickford, M., Thomas, H., 1984. An aberrant new bovid (Mammalia) in subrecent deposits from Rusinga Island, Kenya. Proceedings of the Koninjlijke Nederlandsche Akademie van Wettenschappen B87, pp.441–452. [Abstract only]

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The largest of the rodents

Guinea pigs are common pets around the world, with over one million of these furry, or sometimes naked, little rodents being cared for by people. They are relatively easy to look after, and pretty cute too. My daughter likes to watch guinea pigs on You Tube – she finds it relaxing. I was flabbergasted to see that some videos of guinea pigs just sitting or eating, have over 10 million views! People do like the cuteness of these relatively large rodents. Capybaras, the largest living rodent and close relative to the guinea pig, have the same cuteness appeal. Their sleepy looking eyes and docile nature, along with their large size win the hearts of whoever sees them.

Endemic to South America, capybara are very large rodents, about the size of a fairly large dog, only much rounder and shorter legs. But they are not the biggest rodents to have waddled on Earth.  This crown currently belongs to the enormous rodent Josephoartigasia monesi, which was about as large as a cow!

The massive rodent, Josephoartigasia monesi from South America.

This enormous beast was found in rocks dating between 4 and 2 million years old, and has only relatively recently described in 2008. (Another example of the importance of museum collections, the skull was in the National Museum of Natural History in Uruguay, after being excavated in 1986.) This skull, missing the lower jaw, is a whopping half a meter long. Rodents are not this big! The capybara’s is less than a third this length. For something so large, how do we know it’s a rodent and not something else? It’s the teeth that give it away.

Teeth are very diagnostic in mammals. Different groups have their own unique shapes, which are a little modified within species. All the species belonging to the Order Carnivora, for example, have large conical canines, flat sharp incisors, large sharp premolars, and slicing molars. All groups of carnivores share these traits, although within the group, different species will have slightly modified versions depending on their dietary needs. (The European sabretooth cat, Homotherium, for example, has serrations on its incisors which is like a hot knife through butter. Only the butter is flesh.) Rodents on the other hand, belong to the Order Rodentia, and have four very large incisors (two on the top, two on the bottom), which grow continuously throughout their lives. Most species have no canine or premolars, with a gap between the incisors and the tough ridged, plated molars. The teeth of J. monesi are the teeth of a rodent.

So far, we only have the skull. But this can still give us a lot of information, including its size and who it is related to. The bone structures in the skull of J. monesi, along with the premolars and teeth, show it belongs to the Family of rodents called Dinomyidae. Although once a very diverse group, appearing around 30 million years ago, today there is only one living species, the pacarana, which is about the size of a cat. Various measurements and analysis of the skull put J. monesi in the range of 1200kg, which is about the same as a cow or bison.

The last surviving member of the Dinomyidae, the lovely pacarana (Dinomys branickii). (Photo Benjamin Frable. Public Domain)

The skull and teeth also provide clues about the animals feeding habits, and the environment it lived in. The bones which attached the cheek muscles are quite slender, and this hints that the muscles were relatively small for such a big animal. This along with the relatively small grinding teeth suggest that the diet was softer vegetation and possibly fruits. They may have eaten aquatic plants, as other fossils found with J. monesi are typical of a delta type environment with nearby forests, similar to the environment of the capybara today. The large incisors have been compared to the tusks of elephants, which may have been used for digging or scraping for food, and even fighting for defence or for females.

There is still a lot more to learn about this huge beast, and when more fossils of the skeleton are found, they will give even more information. The rocks the skull was found in age to between 4 and 2 million years ago, so more fossils will also give us a better time range for this species and give us clues to why it became extinct. The skull was found alongside other fossils, such as giant sloths and sabretooth cats. Sabre tooth cats only made their way to South America around 2.7 million years ago. Before then, J. monesi would have been adapted to the natural predators of South America, which was an isolated landmass. With North and South America joining around 2.7 million years ago by underwater volcanoes and sediment, this meant that animals from both landmasses could move between the two. New predators, like sabre tooth cats would have seen these giants as an easy meal. That’s one possibility. The climate was also becoming a little cooler around this time, and we don’t know if this had an impact on our cow-sized rodent.

It would be quite something to see this enormous creature wallowing in the shallow waters of a river in South America. With the rustling leaves of a nearby tree as a giant sloth slowly moves past. And perhaps a low rumbling of a sabretooth cat nearby, heard but not seen. The mammals of South America at the beginning of the Pleistocene were part of a truly unique landscape.

Written by Jan Freedman (@JanFreedman)

Further reading:

Blanco, R. E. 2008. The uncertainties of the largest fossil rodent. Proceedings of the Royal Society. 275. pp.1957–1958. [Full article]

Blanco, R. E., Rinderknecht, A., & Lecuona, G. 2012. The bite force of the largest fossil rodent (Hystricognathi, Caviomorpha, Dino[1]myidae). Lethaia 45. pp.157–163. [Full article]

Cox, P. G., Rinderknecht, A., and Blanco, R. E. 2015. Predicting bite force and cranial biomechanics in the largest fossil rodent using finite element analysis. Journal of Anatomy. 226. pp.215-223. [Abstract only]

Cox, P. G., Rinderknecht, A., and Blanco, R. E. 2015. Masticatory biomechanics of the largest fossil rodent. The FASEB Journal. https://faseb.onlinelibrary.wiley.com/doi/10.1096/fasebj.29.1_supplement.865.7

Fields W.R. 1957. Hystricomorph rodents from the Late Miocene of Colombia, South America. Univ. Calif. Publ. Geol. Sci. 32. pp.273–404. [Full article]

Millien, V. 2008. The largest among the smallest: the body mass of the giant rodent Josephoartigasia monesi. Proceedings of the Royal Society. 275 (1646). pp.1953-1955. [Full article]

Mones A. 2007. Josephoartigasia, Nuevo nombre para Artigasia Francis & Mones, 1966 (Rodentia, Dinomyidae), non Artigasia Christie, 1934 (Nematoda, Thelastomatidae) Comun. Paleontol. Mus. Hist. Nat. Montevideo. 36. pp.213–214.

Rinderknecht, A., & Blanco, R. E. 2008. The largest fossil rodent. Proceedings of the Royal Society. 275 (1637). pp.923-928. [Full article]

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The littlest Homo

The field of human evolution is fascinating. New finds are changing our knowledge each year as more and more incredible discoveries are made. The 21st century has really opened our eyes to how wonderful and diverse our ancient relatives were. Ancient cave art in Indonesia, Neanderthal art, and new fossils pushing back the date of the origin of our own species. As well as these amazing insights to how our relatives lived, several new species have been discovered too! It really is an exciting time for palaeoanthropology.

I am regularly reminded of how much we are discovering about our own evolution and that of our relatives as my thumb scrolls through my phone on Twitter. I see some amazing facts. Old historical discoveries. New exciting discoveries. And one of my favourite Twitter science people is Dr Paige Madison. Every day she tweets about the history of science, the curious characters, and anthropology amazingness. And every day I learn something new. The 21st century is showing that our past is more complicated that we thought. Groups from one species travelled out of Africa, often at different times. New tools, new art, are shining a light on how some of ancestors lived. There is no simple narrative to our own evolutionary history.

One of the most astounding discoveries this century, well the most astonishing in the whole history of palaeoanthropology, is the discovery of a very small species of human on the Island of Flores: Homo floresiensis. And it was a very small species. Reaching just over a meter tall, these were real hobbits. Our ancient relatives, the Australopithecines, were small (the famous skeleton of Lucy was about the same size). But over time hominins have grown taller, and that’s what makes this species such a curious find: it wasn’t a species from 3 million years ago, it was around until fairly recently.  I’ve been itching to write about this little hominin for a long time, so I contacted Paige. Having recently finished her PhD in historical anthropology examining the history of Neanderthals, Australopithecines, and the hobbit, she was the perfect person to talk to about these little humans. She has studied the history of their discovery. Spent months working at the site. She has lived these enigmatic humans for over three years.

Yours truly next to a replica skeleton of Homo floresiensis. On display at the Natural History Museum, London.

The first fossils of H. floresiensis were excavated in 2003. “This was such a huge discovery,” Paige says from her desk as we talk through our laptops. Behind her, a cast of the skull of H. floresiensis sits. “The findings were published in 2004. The scientists didn’t expect such a huge response from the media. Phones were ringing every day.” The world went crazy wild for this new find. A new human species that was only a little over a meter tall. These were fossils of adults, not juveniles. It wasn’t long before it was nicknamed the hobbit. “It’s quite funny really. The team nicknamed it the hobbit before it was published, and even joked about naming the new species Homo hobbitus!”

I wanted to know more about this mysterious species.

Fossils were found in the cave of Liang Bua Cave on the Indonesian Island of Flores. “It’s beautiful.” Paige tells me, reminiscing. She has spent many weeks working in the cave. “It is quite high up, about 500 meters above sea level. When you are inside it’s cool. So perfectly cool, it should be the marker for how offices should set their temperatures. The closest translation for Liang Bua is probably ‘cool cave’. Because it is so cool, people can work in there easily in just a T-shirt or a light jacket. There are currently four pits that are being excavated, each 3 meters by 3 meters. And we have 45 people excavating.”

I try to visualise it. Liang Bua is a very large cave, and the excavation is meticulous. It’s tempting to just go in and dig. But archaeology requires a lot of patience. A grid is chosen, and then, slowly each layer is excavated. Everything is recorded as the archaeologists work. “One visitor said to me ‘that looks terribly boring’ as they watched people excavating!” Paige joked as we talked about the excavation. The Wae Racang River is close by, and this probably gave the cave the really nice layers that they have found: each time it flooded, sediment was gently pushed into the cave, building up over time. “The layers in the cave are really clear. The only trouble is, there are interesting things in the top layers, which are younger, so we have to be so patient to get to the older layers below where H. floresiensis is found, which we call the hobbit layers. With the sediment around 20 meters thick, it takes a long time to reach the oldest layers at the bottom. There is very likely decades more research in this one site alone. We are training locals how to excavate and record and study the finds, so that the fossils in their country can be studied by the next generation of Indonesian scientists.”

Liang Bua is a large cave site, with a large number of workers excavating the sediment. Visitors to the caves are normal, with tourists coming to see the home of the hobbits. (Photo Liang Bua team).

Working in a museum, I am well aware of Europeans taking fossils, and animals and plants, for their own research in the past, so I was really happy to hear the collaborative work the team at Liang Bua are doing.  Paige could sense this. “This isn’t actually new. Many of the local excavators have been there a long time. Some for decades. The research itself has long been led by Indonesians, just partnered with foreign scientists because they are able to bring in the funding. Thomas Sutikna is a great example, he has been directing the excavations since the early 2000s and is himself the 2nd generation of Indonesian archaeologists to do so (his advisor, Raden Pandji Soejono was the first, emerging as an archaeologist after Indonesia won its independence in 1949). Sutikna is really leading the charge of training the next generation of Indonesian scientists, along with Matt Tocheri who has two Indonesian archaeologists completing masters degrees at his university in Canada right now.” All too often we assume that the people behind the research are European or American. It’s so important to know everyone involved in the science behind these discoveries.

The meticulous work of the archaeologists painstakingly excavating with incredible patience. The layers of the cave sediment can be seen in the background. (Photo Liang Bua team)

There have been relatively few fossils of H. floresiensis found so far: a very well-preserved skull, a jawbone, and fragmentary bones of the skeleton. All in all we have the fossils of just seven individuals from this species. I assumed that this unique little human evolved from Homo erectus, a human ancestor who was one of the first species to travel outside Africa. H. erectus was incredible successful, living from around 2 million years ago until just 100,000 years ago. It was a widespread species too, and fossils have been found across Europe and Asia. And H. erectus even made it to some islands. If they got to Flores, that population could have evolved into a smaller size. We have seen this before with dwarf mammoths, and dwarf hippos: large species evolve to be smaller on islands, as an adaptation to less food supplies.

I talk a little too quickly about dwarf mammoths. Paige patiently lets me finish, and with a mischievous smile, she says that’s one theory. She picks up her cast of the skull behind her. “The skull of the little floresiensis does share similarities to erectus. When I first saw the skull, I noticed how thick the bone was, just like erectus. It is possible that it was the ancestor. But there is another theory. The skull does share traits from erectus, but the skeleton doesn’t look anything like it. Bones do change when animals are reduced in size, but the skeleton of floresiensis shows too many changes. Too many to make sense that erectus was the ancestor. There are suggestions that the ancestor may from an Australopithecus species.” I nearly spit out my tea. There were several species of Australopithecus, very early relatives to us, dating from around 4 million years ago to around 1.6 million years ago. And no fossils of any Australopithecus species have been found outside of Africa. If this theory is right, that is big. Really big. After listening to me getting too excited, she tantalisingly adds, “If an Australopithecus, or a very early Homo, species was the ancestor, these were already small hominins, so they wouldn’t have shrunk in size. It is possible. It’s just that we haven’t found them yet on the mainland of Asia. Yet.”

A cast of the skull of Homo floresiensis on display at the Cantonal Museum of Geology, Switzerland. (Photo Public Domain).

The site is incredible, and the painstaking work to excavate everything so meticulously is remarkable. Excavations have also found lots of stone tools in the deepest layers (the hobbit layers), so it looks like the hobbit was here for quite a while. “It’s quite amazing,” she talks with excitement, her hands waving, “we have stone tools at the deepest levels, and all the way up until when they disappear. It looks like Liang Bua was a regular camp site for this human.” Even though I am sitting in my little home office in England, and Paige is in hers in Denmark, I can see the passion as she speaks. “The oldest layers are about 200,000 years old, and until 100,000 years ago we find just stone tools, no fossils of floresiensis. Then we find fossils from about 100,000 years ago until around 46,000 years ago. That’s when they vanish from this site. And in the layers above we find evidence of our species, Homo sapiens. Interestingly there is no evidence of fire in the deeper layers relating to the hobbit, but there is evidence of fire in the layers where we find H. sapiens.”

The animals living alongside H. floresiensis add to the mystery of this island in the past. Komodo dragons lived here, and still do, although they have now moved to more coastal areas. There were stranger things too, more fitting for a fantasy film than reality. Giant storks, over two meters tall, giant vultures, giant rats the size of a cat, and pygmy elephants. Evolution on Flores was its own unique laboratory. And the world these hobbits lived in was unlike anything today. “There were a lot of rat bones, making up about 78% of the fossils found, and included giant rats. That’s a big percentage. This is really good for us because we can work out the environment with the fossils. The rats from the older layers near the bottom show a more open environment with less forest. Then around 46,000 years ago we see just two species instead of several, and these two species are more at home in a forest environment, similar to what Flores is like today.”

Something happened 46,000 years ago. No H. floresiensis have been found after that time. All the mega-fauna, apart from the Komodo dragons, disappear as well. And the rat species change too. And then above this date, we see our species in the cave. Coincidence? Perhaps it is. “It’s not always as clear as we would like. Around 46,000 years ago we find a layer of ash. It’s really thick, showing that there was a very big volcanic eruption and it must have been close by. Then above the ash layer we find no hobbits and find our species instead. But this doesn’t mean the hobbits went extinct at that time. Like the Komodo dragon, they could have just moved somewhere else.” The timing of extinction is always contentious. Just because we don’t find fossils of a species above a certain point, doesn’t mean that is when they became extinct. Chatting about the fossil record and lack of fossils, Paige smiles. “At the moment Liang Bua is the only site on Flores with fossils of floresiensis. We are looking at other places where there could potentially be fossils. And these could tell us so much more about this species. It is an incredible species, and we have only scraped the surface.”

Archaeologist, Dr Thomas Sutikna, examining the stragigraphical layers of the cave. Note the thick grey layer behind him. This is the ash from the volcanic eruption around 46,000 years ago. (Photo Dr Hanneke Meijer)

There’s a twist in the tale. In 2007, some fossils were found in Callao Cave in Luzon, in the Philippines. Originally described as belonging to modern humans, more fossils were found, showing another diminutive hominin. The fossils of this new species, Homo luzonensis, date to around 50,000 years ago, and evidence in the cave suggests they may have been there as early as 770,000 years ago. “For an early human species to cross the seas around Indonesia would have been very difficult. The currents are so strong. It might be that luzonensis offers some new clues as to how the hobbits got to Flores. There are a lot of islands in the area, and at the minute not a lot of exploring for fossil sites. This is a really exciting time for us and luzonensis could offer hints at ancient routes.”

Homo floresiensis is an incredible discovery. It shows us that our family tree is a lot more bushy than we originally thought. It also sparks our imagination. These tiny humans living on a mysterious island, along side giant killer predators. Not only that, but it shows how our own species has an incredibly diverse history. There is so much still to learn about this enigmatic human. How they got here. Who did it evolve from. We know from Liang Bua that they lived on Flores from at least 200,000 to 46,000 years ago. But did they get here earlier than that? Did they survive longer than that? Were they spread across the entire island? There is a myth on the Island of small people living in the forest, the ebu gogo. Fascinatingly this myth comes from a different region, over 100km away. Future excavations could show that the hobbit lived across Flores and even overlapped with our own species. Today, palaeoanthropology is revealing fascinating insights into our ancient relatives, and our own species. Tomorrow, who knows what discoveries we will see.

Written by Jan Freedman (Twitter @JanFreedman)

A very special thank you to Paige Madison for spending the time to talk to me for this blog post, and sharing her passion for Homo floresiensis. If you don’t already, follow Paige on Twitter (@FossilHistory)

Further reading:

For a nice read about the myth of the ebu gogo on Flores: The myth of the ebu gogo.

There is nice background to the hobbit here: The hobbit at 15.

Read more about those giant rats: Hobbit humans story gets a twist from thousands of rat bones.

Paige wrote about her time she spend in Liang Bua at night: Nightfall in the hobbit cave.

Argue, D., & Groves, P. 2017. The affinities of Homo floresiensis based on phylogenetic analysis of cranial, dental and postcranial characters. Journal of Human Evolution. 107. pp.107-133. [Abstract only]

Argue, D., et al. 2009. Homo floresiensis: A cladistic analysis. Journal of Human Evolution. 5. pp.623-639. [Abstract only]

Brown, P., et al. 2004. A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia. Nature. 431 (7012). pp.105-1061. [Abstract only]

Brumm, A., et al. 2010. Hominins on Flores, Indonesia, by one million years ago. Nature. 464 (7289). pp.748-752. [Abstract only]

Culottta, E. 2005. Palaeonantrhopolgy – new hobbits bolster species, but origins still a mystery. Science. 310. pp. 208-209. [Abstract only]

Détroit, F., et al. 2019. A new species of Homo from the Late Pleistocene of the Philippines. Nature. 568. pp.181-186. [Abstract only]

Ingicco, T., et al. 2018. Earliest known hominin activity in the Philippines by 709 thousand years ago. Nature. 557 (7704). pp.233-237. [Full article]

Jungers, W. L., et al. 2009. The foot of Homo floresiensis. Nature. 459 (7243). pp.81-84. [Abstract only]

Mijares, A. S., et al. 2010. New evidence for a 67,000 year old human presence at Callao Cave, Luzon, Philippines. Journal of Human Evolution. 59 (1). pp.123-132. [Abstract only]

Moorwood, M. J., et al. 2004. Archaeology and age of a new hominin from Flores in eastern Indonesia. Nature. 431 (7012). pp.1087-1091. [Abstract only]

Sutikna, T., et al. 2016. Revised stratigraphy and chronology for Homo floresiensis at Liang Bua. Nature. 532 (7599). pp.366-369. [Abstract only]

Weston, E. M., & Lister, A. M. 2009. Insular dwarfism in hippos and a model for brain size reduction in Homo floresiensis. Nature. 459 (7243). pp.85-88. [Abstract only]

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In cold pursuit

From feathered dinosaurs to woolly mammoths, countless animals that no longer live have come to pervade modern popular culture. Snuck into a world of dragons, witches, and ice zombies in Game of Thrones (or A Song of Ice & Fire), the dire wolf recently experienced a slightly confusing reintroduction into the beloved pantheon of extinct megafauna, as it may appear to some to be mythical by association. Dire wolves were very much real, and we have known about them since the mid-nineteenth century. These charismatic canids roamed the Americas and parts of eastern Asia for more than 100,000 years, going extinct early into the Holocene around 9,000 to 10,000 years ago (BP).What were they really like, and why did they go extinct? In answering these questions, we can also begin to explore the diverse ways in which information is gleaned from fossils.

We start our story in the La Brea Tar Pits in Los Angeles, USA, the largest discovered fossil site containing dire wolves, numbering beyond 4,000 individuals. Tar pits form from crude oil seeping up to the earth surface and congealing into asphalt. The La Brea Tar Pits contained the remains of thousands of animals representing several extant and extinct species that fell into and became deposited in the asphalt between 40,000 and 8,000 BP.  Excavations at La Brea began in 1913, and the asphalt-preserved fossils continue to be used to reimagine not just the organisms themselves, but also the world that they inhabited.  

The wall of dire wolf skulls on display at La Brea. This display holds around 400 skulls. (Photo Jan Freedman)

A predator and its prey

One way to get to know an apex predator is through its preferred prey. Many chemical elements exist as multiple, stable isotopes that carry different numbers of protons in their nuclei. For instance, carbon exists as the common type 12C and the much rarer 13C, while nitrogen exists as the common and rare 14N and 15N, respectively. The stable isotope ratios 13C/12C and 15N/14N vary across different kinds of plants based on their environment and how they incorporate the elements from the atmosphere, and in animals depending largely on their diets. Stable isotope compositions of biological tissues such as bone can reconstruct ancient diets and food webs. A 2007 study first identified how isotope ratios in modern wolves are related to that in their prey, beavers and moose. Applying these findings to isotope ratios in the bones of dire wolves and several candidate herbivore prey species from the La Brea Tar Pits, the authors inferred that dire wolves primarily preyed on horses, and to a lesser extent on mastodon, sloth, and grazers such as bison.

A model of a dire wolf on display at La Brea. (Photo Jan Freedman)

We know dire wolves were likely pursuit predators who chased down their prey and attacked with their jaws alone, based on our knowledge of extant wolves and other canids. This has also been verified through fossil evidence. The authors of a 2017 study predicted and found that patterns of skeletal injuries differed between La Brea dire wolves and sabretooth cats, which were likely ambush predators. Sabretooth cats had frequent spinal injuries from grappling with their prey, while dire wolves tended to have high rates of trauma across all four limbs, consistent with chasing down prey.

Clues to extinction

Patterns and frequencies of tooth wear and damage have been found in living animals to be informative of feeding behaviors. A 1993 study brought this understanding to the study of several La Brea carnivores, including dire wolves. The authors found a high frequency of tooth breakage across the carnivores, likely from tooth-bone contact, suggesting greater utilization of carcasses compared to modern carnivores. Was this due to a decline in available herbivore prey in the late Pleistocene, eventually leading to the extinction of these predator species?

To answer this question, a 2002 study compared dire wolves preserved in two La Brea pits dated to ~15,000-14,000 BP and ~13,000-12,000 BP, respectively, and found that carcass utilization actually decreased over this time span. Times appear to have been especially tough around ~15,000-14,000 BP, leading to more complete consumption of prey to avoid scavenging by other competing predators. The subsequent decline in this behavior may reflect dwindling predator densities as dire wolves and other carnivores approached extinction. A 2015 study found a similar temporal pattern, among other findings.

The study investigated several measures of morphological variation using the remains of 83 dire wolves as well as 97 sabertoothed cats from La Brea, spanning the period between 40,000 and 12,000 BP. One of these measures, fluctuating asymmetry, quantifies (to a reasonable extent) developmental instability, the tendency of traits to deviate from the target phenotype. Symmetrical traits such as the left and right sides of the face are controlled by the same genetic and developmental pathways, and any asymmetry implies developmental instability, typically caused by some form of external stress. The study found increasing fluctuating asymmetry in dire wolves over time from 40,000 BP until ~15,000-14,000 BP, possibly in response to environmental stress associated with rapid climatic transitions during that period. This was followed by a decline in fluctuating asymmetry 13,000-12,000 years ago, mirroring the changes in tooth wear and breakage over the same interval. Together, these studies imply that climatic instability leading up to the Holocene put dire wolf populations under stress, likely through disrupting populations of their herbivore prey, which they never completely recovered from. Humans are also thought, quite contentiously, to have played some role in Pleistocene megafaunal extinctions.

A dire wolf skeleton, mounted in pursuit of prey. (Photo Jan Freedman)

A wolf by any other name

We end with a reflection on the evolutionary relationships of the dire wolf. Over the last two decades, enormous advances have been made in techniques to extract preserved DNA from ancient remains. Ancient DNA provides snapshots of the evolutionary past, and in the case of extinct animals, a way to infer their relationships with extant taxa. A 2021 study looked at ancient DNA from dire wolf remains, and found that dire wolves were in fact distantly related to extant gray wolves. The two species had diverged from a common ancestor more than 5 million years ago, and look so similar largely because they convergently adapted to lives of pursuit predation. To place this in context, jackals, coyotes, and gray wolves are more closely related to each other than to dire wolves.

While modern canids like grey wolves and coyotes are known to sometimes interbreed, the study found that this was not the case between dire wolves and grey wolves. Hybridization leads to the introduction of new genetic diversity, which can often help a species adapt to changing conditions. Dire wolves were not beneficiaries of this process as they disappeared along with the prey species they had been adapted to hunting and eating.

Humans have likely been coming across and pondering fossilized remains of extinct animals for thousands of years. Records of such encounters are thought to persist today in the form of mythological beasts reimagined from the fossils, such as giants, griffins, and dragons. Modern day reconstructions from fossil remains are, as we have just seen, much less fanciful, but far more exciting in what they tell us about ecosystems and episodes in evolutionary history that have been lost to time.

Written by Ornob Alam (Twitter @genomeinquirer)

Edited by Jan Freedman (Twitter @JanFreedman)

Ornob is a graduate student in Michael Purugganan’s lab at New York University. His dissertation research examines the demographic and evolutionary history of domesticated Asian rice in the context of past climate change and human migrations.

Further reading:

Binder, W. J., Thompson, E. N., and Valkenburgh, B.V. 2002. “Temporal variation in tooth fracture among

Rancho La Brea dire wolves,” Journal of Vertebrate Paleontology, vol. 22, no. 2, pp. 423–428, Jul. 2002, doi: 10.1671/0272-4634(2002)022[0423:TVITFA]2.0.CO;2. [Abstract only]

Broughton, J. M., and Weitzel, E. M, 2018. “Population reconstructions for humans and megafauna

Suggest mixed causes for North American Pleistocene extinctions,” Nature Communications, vol. 9, no.

1, Art. no. 1, Dec. 2018, doi: 10.1038/s41467-018-07897-1. [Abstract only]

Brown, C., Balisi, M., Shaw, C. A., and Van Valkenburgh, B. 2017. “Skeletal trauma reflects hunting

behaviour in extinct sabre-tooth cats and dire wolves,” Nature Ecology & Evolution, vol. 1, no. 5, Art. no.

5, Apr. 2017, doi: 10.1038/s41559-017-0131. [Abstract only]

Fox-Dobbs,K. F. D.,  Bump, J. K. B. K., Peterson, R. O. P. D., Fox D. L. F., and P. L. K. L. Koch, P. L. K. 2007.

“Carnivore-specific stable isotope variables and variation in the foraging ecology of modern and ancient

wolf populations: case studies from Isle Royale, Minnesota, and La Brea,” Canadian Journal of Zoology,

doi: 10.1139/Z07-018. [Abstract only]

Goswami A., Binder. W. J., Meachen, J., and O’Keefe, F. R. 2015. “The fossil record of phenotypic

Integration and modularity: A deep-time perspective on developmental and evolutionary dynamics,”

Proc Natl Acad Sci U S A, vol. 112, no. 16, pp. 4891–4896, Apr. 2015, doi: 10.1073/pnas.1403667112.

[Full article]

Perri, A. R., et al., 2021. “Dire wolves were the last of an ancient New World canid lineage,” Nature, vol.

591,No. 7848, Art. no. 7848, Mar. 2021, doi: 10.1038/s41586-020-03082-x. [Abstract only]

Stewart, M., Carleton, W. C., and Groucutt, H. S. 2021. “Climate change, not human population growth,

correlates with Late Quaternary megafauna declines in North America,” Nature Communications, vol.

12, no. 1, Art. no. 1, Feb. 2021, doi: 10.1038/s41467-021-21201-8. [Abstract only]

Vanvalkenburgh, B., and Hertel, F. “Tough times at la brea: tooth breakage in large carnivores of the late

pleistocene,” Science, vol. 261, no. 5120, pp. 456–459, Jul. 1993, doi: 10.1126/science.261.5120.456.

[Abstract only]

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A beautiful world

Our planet is remarkable. Think about it for a second. Oceans full of fish, mammals, invertebrates. Land covered by plants, incredible insects, and amazing animals. The skies full of birds, mammals, and insects. All this life around us living, surviving, dying. Millions of different species of all shapes, sizes, and colours sharing this planet with us. Each species unique. Each playing its own role in the complex ecosystems. It is easy for us to take this for granted with the pressures of our daily lives. Stop. Listen to the bird song. Watch the gentle sway of the leaves in the wind. Spend a few minutes looking at that insect: that little creature oblivious to our lives and seemingly frantically carrying on with theirs. We live in a beautiful world.

It has always been a beautiful world. Our blog posts about the animals of the Pleistocene try to share how amazing animals in the not too distant past were. No matter how bizarre. And there were some truly wonderfully weird creatures. Weird to our eyes. For them, they were perfect. Not matter how weird they seem to us, they were well adapted to their environments. They lived. The odd looking chalicotheres, which looked like a mix between a horse and a gorilla. The spectacular deer, Eucladoceros, with remarkable antlers reminiscent of some kind of forest god. And so, so many more. Including this beast, Celebochoerus, the shovel pig.  

Celebochoerus was a genus of pigs that lived in Indonesia. They were around the same size as wild boar today, but the shovel pig had one big difference: the tusks were enormous! Wild boar can be quite ferocious. Dogs that are with the hunting party are often injured, and in the early 15th century people were injured too. Let’s not forget king Robert Baratheon of Westeros was severely mauled on a boar hunt, which was the end for him, and the beginning of the brutal fight for the throne: really, I blame that boar for the whole seven, bloody, seasons. The enormous tusks on Celebochoerus would undoubtably have provided protection against predators. They would have also been useful in moving vegetation and debris when searching for food; giving the name, shovel pig.

The skull of Celebochoerus heekerenis showign those huge tusks. (Image from Museum Geologi, reproduced with permission)

There were two species of this wonderful beast; C. heekereni living on the large Island of Sulawesi in Indonesia, and C. cagayanensis which was discovered fairly recently in 2016, on the larger island of Luzon in the Philippines. Looking at the fossils hints that the shovel pigs ancestors originated in Taiwan, moving into Indonesia, and then into the Philippines. We know it lived from the Late Pliocene around 3 million years ago until the Middle Pleistocene, around 1 million years ago. For a change, it looks like humans were not the reason for this wonderful creature’s extinction. It appears that other species of pigs moving into their environment pushed them to the edge. There are not a huge amount of fossils and mostly from a few sites, so there is still a lot more we can learn about them. I am pretty excited about future fossil discoveries of this beast to give us lots more information.

The robust skeleton of Celebochoerus heekerenis. (Image from Museum Geologi, reproduced with permission)

Other amazing animals lived alongside the shovel pig in Indonesia, including giant land tortoises, dwarf elephants, and crocodiles along with smaller reptiles and mammals. And the shovel pigs were a part of this amazing ecosystem. Surrounded by rainforest and rivers, it was a beautiful unspoilt time. A time that seems so far away. So difficult to imagine animals like our shovel pig trotting amongst the tress. But it was relatively recent. Just a million years. That is nothing on the whole grandiose scale of geological time.

Our planet has always been glorious. Perhaps, some may argue that it was even more beautiful before humans spread across the globe building giant cities, and destroying forests. It probably was. But this is the world we have. We only have one. A single planet. Earth. So many amazing animals have disappeared throughout time. Strange ones, like the shovel pig. Vanished forever. But we are lucky. We have a whole planet full of amazing plants and animals all around us. Take a moment to look. And really see the beauty.  

Written by Jan Freedman (@JanFreedman)

Thank you to the Museum Geologi for allowing us to reproduce their images for this blog.

Further reading:

Groves, C. 2001. Mammals in Sulawesi: Where did they come from and when, and what happened to them when they for there? In Metcalfe, I, et al. Faunal and Floral Migration and evolution in SE Asia-Australasia. CRC Press. Pp. 333-342. [Full article]

Hooijer, D. A. 1954. Pleistocene vertebrates from the Celebes. VIII. Dentition and skeleton of Celebochoerus heekereni Hooijer. Zoologische Verhandelingen. [Full article]

Hooijer, D. A. 1972. Pleistocene vertebrates from the Celebes. XIV. Additions to the Achidiskodon-Celebochoerus fauna. Zoologische Verhandelingen. [Full article]

Ingicco, T., van den Bergh, G., de Vos, J., Castro, A., Amano, N. & Bautista, A. (2016). A new species of Celebochoerus (Suidae, Mammalia) from the Philippines and the paleobiogeography of the genus Celebochoerus Hooijer, 1948. Geobios, 49 (4), 285-291. [Abstract only]

Laurent, A. F., et al. 2018. Synchronous diversification of Sulawesi’s iconic artiodatyls driven by recent geological events. Proceedings of the Royal Society. B. Biological Sciences. 285 (1876). [Full article]

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The World Before Us

Tom Higham helps run the Research Laboatory for Archaeology and the History of Art (RLAHA) at the University of Oxford. He has been a pioneer of improving the efficacy and accuracy of radiocarbon dating, introducing methods that are now global standards in radiocarbon work, like the ultrafiltration of collagen molecules and single amino acid dating. His work has been published in every academic and popular venue imaginable, from Science to the super soaraway Sun and everywhere in between. Thanks to dating improvements implemented by Tom and his team, we now have secure chronologies for the extinction of Neanderthals and a host of other Pleistocene megafauna.

I first met Tom as a very green PhD student, way back in 2002. In those heady Oxford days, our ancient DNA group had close ties with RLAHA and we would often hold informal meetings in the legendary Lamb&Flag pub on St. Giles[1]. Tom is a very enthusiastic and effusively friendly Kiwi whose wide-ranging interests were not limited to radiocarbon, but every aspect of life in the late Pleistocene including ancient DNA, stable isotopes and a host of scientific archaeology methodologies. In Science, I’ve found that people who are positively infectious with enthusiasm are the perfect teachers. Simply hanging about with Tom lead to an organic diffusion of knowledge, that taught me an awful lot about radiocarbon, isotopes, Neanderthals and much more. I was delighted when I heard through Facebook that he was using lockdown to write a book, and determined to buy a copy for myself as soon as feasible after publication. Luckily, I was able to source one through another fabled Oxford institution; Blackwells bookshop on Broad street, and Tom was kind enough to sign it for me. “The World Before Us” is a book that crams everything a global expert who has been at the vanguard of many of palaeoanthropology’s biggest breakthroughs of the last two decades can tell us into 300-odd pages of gripping prose.

I’ve devoured it over the last week and this review is an expression of how much I enjoyed reading it. If you have read much sci-comm then you know, as I do, just how much of it is as dry as a ship’s biscuit. The tightrope between giving the reader enough information to be interesting, and imbuing a sense of narrative and flow is a tricky one that I know all too well myself.

Tom’s book describes how he has been involved with globally important research into Neanderthal extinction, the jaw-dropping discovery of the Denisovans, and the unexpected Hobbits of Flores.

In books like this it’s all too easy to produce a dusty tome of sites, dates, and names but that is a million miles away from what Tom has produced. He has injected enough of himself, his wry observations and subtle humour, to make the tangled story of our origins a real page-turner. Discussions of working in the famous Denisova cave are fascinating, and the discovery of “Denny” the F1 hybrid girl between a Neanderthal mother and a Denisovan father is really brought to life. Her whole story was pieced together from a 1” fragment of indeterminate bone sieved from Denisova cave and identified by ZooMS[2].

What’s great about “The World Before Us” is that Tom synthesises many strands of evidence to tell a convincing best-guess scenario about what our relatives and ancestors were up to. A lot of this information has had to be gleaned from fairly dense academic papers and Tom does an excellent job of distilling the vital essences to add to the overall story. Along the way, thanks to his many connections, he calls on various experts who make cameos in the book and give first-person insight into the advances they’ve made.

Overall, the book massively succeeds in its aim of making the latest advances in our understanding of human origins understandable by everyone and does so in a way that never makes it feel hard to comprehend.  Despite being involved in many of the papers that have fuelled this advancement, Tom never makes the prose about himself but is generous with credit to all who have contributed. After finishing the book it feels like you’ve been on a whirlwind ride through all that’s new and exciting in human origins and with a good appreciation of the collaborative nature of science. Tom’s optimism is ever present in the writing and you can palpably sense this when the books ends, all too soon, with the sentiment “if you think this stuff is cool, wait ‘til you see what’s gonna happen in the next ten years!”.

[1] After 450 years of continuous trading in Oxford’s city centre, the Lamb and Flag closed in January 2020, seemingly permanently. How a college as infamously rich and moneyed as St. Johns can allow this shortsighted asset stripping to happen is a mystery to me and many others.

[2] ZooMS (Zoology by Mass Spectrometry) is a technique that uses comparison of bone proteins from small fragments of bone to identify them to species, when comparative morphology is impossible.

Written by Ross Barnett (@DeepFriedDNA)

You can follow Tom Higham on Twitter @TommyHigham

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The forgotten dogs of South America

Abya Yala was the land of dogs for a long time.* This is where they evolved. On a solitary, large landmass drifting through a vast ocean. A landmass that Europeans would later call North America. These very familiar animals evolved around 20 million years ago, where they gave rise to a huge number, and huge variety, of different species.

The family of dogs is much bigger than just our friendly pets (although the variety within our beloved pets is enormous!). They were once a very diverse, very successful, group of carnivores, and are still diverse and successful today. Of the three different families of canids that have lived (the Hesperocyoninae, Borophanginae, and Caninae), only the Caninae survive.

Today, there are 27 different species of canids across the world, including wolves, numerous species of foxes, bush dogs, and of course our pets. They are familiar animals to us (the scientific name for our household dogs is Canis familiaris) and as a family, they have been around for quite some time, evolving around 34 million years ago. They lived solely in Abya Yala, until around 8 million years ago when they moved across the Berinigia land bridge, and into Asia, Europe and Africa.

It wasn’t until around the start of the Pleistocene, around 2.6 million years ago, that canids made their way to South America. This equally large landmass was separated from North America, until around 3 million years ago when under water volcanoes, and huge deposits of marine sediments built up and formed the Isthmus of Panama. A connection linked these two lonely landmasses together for the first time in over 200 million years. They didn’t so much as find each other, rather, the natural movements of our planet brought them together: two lost souls connected at last.

When animals can move easily across land, they will. And they did. They moved across the Isthmus of Panama in their thousands. Animals from South America, like the giant glyptodonts, terror birds, and giant sloths, moved into North America, and animals from the north, like the sabre tooth cats, tapirs, camels and horses moved south. In this mass exchange of wildlife, species of canid also moved down into this new land. And here they flourished. New environments provide new opportunities.

Graphic illustration of what is dubbed, the Great American Biotic Interchange. The formation of the Isthmus of Panama allowed animals to move freely across both continents. (Image Public Domain)

Although canids have been in South America for a relatively short period of time, this is where they are most diverse. There are ten different species living there today. Several are commonly called foxes, only they are not the same species as the familiar red fox we know, only superficially looking like them. There’s also the rather leggy manned wolf (not a wolf, but a completely different genus, but it does have very long legs). And the bush dog, which looks like a cross between a weasel and a miniature bear.

Once canids arrived in South America, they quickly spread and new species evolved. Dozens of species roamed the land during the Pleistocene. One of them was a top carnivore in this new, unexplored land. Discovered in 1891, Theriodictis platensis was one of the largest canids in South America, about the size of a German Shepherd, and it was well adapted to hunting large prey. There were several other large predators in South America along with T. platensis, including several other canid species, the sabre tooth cat (Smilodon populator), jaguars (Panthera onca), pumas (Puma concolor) and the giant short faced bear (Arctotherium angustidens). The Isthmus of Panama brought a whole melange of new predators with it.

The powerful skull of Theriodictis platensis (Image Public Domain)

Fossils of T. platensis have bene recovered from rocks in the Buenos Aires province of Argentina, Bolivia, and southern Brazil. It was relatively widespread, but restricted to the central areas of South America. Associated fossils indicate that this large canid was living on grasslands, hunting camels, horses, deer, and other large herbivores. Their jaws and skulls show that large muscles would have attached, giving this canid a very strong and powerful bite.

This bite may have been powerful enough to crunch through the armour of the mighty glyptodon. Some researchers suggest that these armadillo tanks evolved even more protection after the arrival of these new predators. The range of new carnivores that moved into South American likely pushed this defensive evolution. Isolated bony plates (osteoderms) have been found, which indicate that they were on glyptodonts, but not attached to the main shell. This hints that these isolated osteoderms were to protect the more exposed areas on the body, particularly around the neck. That these new predators caused fairly rapid changes in already well armoured giants, shows that they were quite formidable beasts. This is not all bavardage. At least one glyptodon fossil shows evidence of being attacked by a large predator, which was most likely Theriodictis platensis.

The majority of fossils come from rocks that date to the Middle-Late Pleistocene, around 780,000 – 500,000 years ago. A small number of specimens have been found in older rocks which date to around 1 million years ago. When it comes to extinct species, we can only gauge their span on the planet by the fossil we have found. Fossils of T. platensis show it was around for around just 500,000 years. More fossils in older and younger rocks may show that it was around for longer, but for the minute we know it was on our planet, hunting large herbivores for around half a million years. And then it vanished. We don’t know why. Competition from other predators? Changing environments? Changing climate? One of the great things about palaeontology is that there are still so many questions that will be answered. Sometimes it through new discoveries and fossils. And sometimes the answers are found in collections in museums. It just takes a fresh look at some old bones.

*Postscript: Abya Yala is the name given to the land lived on by indigenous native people. This land was named ‘America’ after Europeans colonised the land. In the late 1490s, it was coined by the German cartographer, Martin Waldseemüller, after the Italian explorer Amerigo Vespucci. Although Abya Yala is used by the Guna people of Panama and Colombia, it is also used by several indigenous groups to describe the continent. In the Guna language it means “land in its full maturity” or “land of vital blood”.

Written by: Jan Freedman (@JanFreedman)

Further reading:

Chimento, N. R., & Donas, 2017. A. First Record of Puma concolor (Mammalia, Felidae) in the Early-Middle Pleistocene of South America Journal of Mammal Evolution. DOI 10.1007/s10914-017-9385-x

Gillette, D.D., Ray, C.E., 1981. Glyptodonts of North America. Smithsonian Contributions to Paleobiology. 40. pp.1–251. [Full article]

Perini, F. A., Russo, C. A. M., & Schrago, C. G. 2010. The evolution of South American endemic canids: a history of rapid diversification and morphological parallelism. Journal of Evolutionary Biology. [Full article]

Prevosti, F. J. & Palmqvist, P., 2001. Análisis ecomorfológico del cánido hipercarnívoro Theriodictis platensis Mercerat (Mammalia Carnívora) basado en un nuevo ejemplar del Pleistoceno de Argentina. Ameghiniana. 38. pp.375–384. [Full article]

Prevosti, F. J., Dondas A., & Isla, F. I. 2004. Revisión del registro de Theriodictis Mercerat, 1891 (Carnivora, Canidae) y descripción de un nuevo ejemplar de Theriodictis platensis Mercerat, 1891 del Pleistoceno de la provincia de Buenos Aires (Argentina). Ameghiniana. 41. pp.245–250. [Full article]

Prevosti, F. J. & Martin, F. M. 2013. Paleoecology of the mammalian predator guild of southern Patagonia during the latest Pleistocene: ecomorphology, stable isotopes, and taphonomy. Quaternary Internatl. 305. pp.74–84. [Abstract only]

Prevosti, F. J., Tonni, E. P., & Bidegain, J. C. (2009). Stratigraphic range of the large canids (Carnivora, Canidae) in South America, and its relevance to quaternary biostratigraphy. Quaternary International. 210. pp.76-81. [Full article]

Soibelzon, L. H. & Prevosti, F. 2007. Los carnívoros (Carnivora, Mammalia) terrestres del Cuaternario de América del Sur. In: Pons GX, Vicens D (eds) Geomorphologia Litoral i Quaternari. Homenatge a D. Joan Cuerda Barceló. Monografies de la Societat d’História Natural de les Balears Special Volume 14, Palma de Mallorca, pp 49–68.

Zurita, A. E., et al. 2010. Accessory protection structures in Glyptodon Owen (Xenarthra, Cingulata, Glyptodontidae). Annales de Paléontologie. 96. pp.1-11. [Full article]

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