Stuck in time

It is mid-November, and beads of sweat form on my forehead. Coalescence is inevitable. And it happens quickly; small beads merged into one humongous droplet, and it begins to meander its way down my nose, and there it dangles,  stubbornly defying gravity.

I am in Los Angeles, walking back in time. Although it is taking me a while to get there. Time travel isn’t quick. I walk out of my motel onto Crenshaw Boulevard, and start walking. On my map, the distance from motel to end point looks pretty short. It turns out I have chosen to walk along the longest road ever built by humans. The air is hot and dry. I feel the warm wind from the heat of the cars drafts against me as they drive past. The sidewalks are practically empty. No one, it appears, walks in Los Angeles.

An hour and fifteen minutes later, I am at the actual end of Crenshaw Boulevard (a street name that will stay with me always). I reach Wilshire Boulevard, one of the main arteries running east west across the city. Here, there is a different feel altogether. Where Crenshaw was lined with motels, fast food restaurants, and small, one story houses, Wilshire has large two story houses fronted by lawns and large drives, and there are tall, glass office buildings home to international businesses. My legs aching, I carry on. I am nearly there. Witshire has more people on the pavements. I pass smartly dressed business men and women darting in and out of doors on their mobiles. Women in Yoga pants appear to effortlessly float past, while the hipster beard makes an appearance more than once. I feel a little out of place, with my dusty, tired sandals, my chequered shirt clinging to my back, and myself looking a little like I have walked across a desert. But I am close. I am not here for the yoga pants. Or the hipster beards. I am here for the sabretooth cats. And the giant sloths.

On Witshire Boulevard, you can take a few paces away from the tall white, shiny, clean buildings, and step back in time. Here, in the middle of the 21st century hustle and bustle, you enter a different era: a time when giant American mastodons stomped. You have reached Rancho La Brea.

On teh busines

On Witshire Boulevard, a giant sabretooth cat welcomes you to the Tar Pits of Los Angeles. (Photo by author)

The Tar Pits at La Brea are world famous. Hundreds of thousands of fossils of Late Pleistocene animals and plants have been recovered at this one site. Animals and plants have become trapped in thick, sticky tar pits, and perished, showing us what life was like from around 50,000 years ago to just a few hundred years ago. What makes this site unique is the vast number of carnivores found here: around 70% of the fossil animals are carnivores. (Simply, an herbivore ended up trapped in the sticky tar, and was feasted upon by carnivores, which then themselves ended up getting stuck too.) It is the large carnivores that have captured the imagination of the media, like the enormous sabretooth cat Smilodon fatalis: which is in fact the state fossil for California. I have come here to find out more.

I meet with the Collections Manager at La Brea Tar Pits and Museum, Aisling Farrell. Her naturally warm welcoming smile and soft Irish accent immediately calms me, and removes any worries I had about being a tiny bit late. She laughs as I explain I walked here: “No one walks in LA!” she exclaims. I guess it is true then.

We walk outside of the George C. Page Museum, towards a fenced off area. Here there are life-sized models of mammoths and an American mastodon dramatically posed as if they were alive 20,000 years ago. I comment on the wonderfully elaborate models. Aisling looks at me, and smiles. “This is an old mine that has filled up with ground water,” she says turning back to look at the mammoth family. “The water table here is really high, so when it rains, this old mine traps a lot of water. It is nice, but it doesn’t show how the animals really got stuck in the tar.” I was about to probe a little more, when an enormous bubble of methane gas loudly came to the surface, and we spoke about the old mines.

One of the first sights a visitor sees,

One of the first sights a visitor sees, a mammoth stuck in ‘tar’ while  two family members watch helplessly.  (Photo by author)

Asphalt has been mined at Rancho La Brea for centuries. Although the site was privately owned in the mid-1800s, locals were allowed to mine asphalt for their own personal use (fuel, buildings, and roads). Bones were noted in the deposits, but they were thought to belong to domesticated animals, and it wasn’t until 1875 that the bones were recognised as fossils. The surveyor, developer, and highly respected citizen, Major Henry Hancock, acquired the land and began commercially mining the asphalt. Palaeontologist, William Denton, from Massachusetts, soon after visited the site and noticed sabretooth cat fossils, along with fossil deer and horse. Even so, it wasn’t until in early 1900 that palaeontologists seriously began studying the bones here.

Today, well over 3.5 million fossils have been recovered from the site. And over 600 species have been identified. This is an incredibly rich site.

With the sun beating down overhead, we walk across the grass. Aisling wants to show me something. We pass a few more small fenced off areas. “There are some spots here where the tar still reaches the surface,” she says, noticing my inquisitive look. “Even today small birds and animals do get stuck here.”

The grass is a vibrant green. A school group is being led by one of the several tour guides at La Brea. A young family is enjoying a picnic. The park is free for anyone to come and enjoy. “The land was left to the city by the Hancock family,” Aisling says as we make our way past a dog walker, with four dogs. “They owned a lot of land in LA. Unusually, they were also very interested in the fossils found here. They could have sold the land, but instead, left it to the people of Los Angeles to preserve the fossil site.”

Hidden amongst the

Hidden amongst the tall buildings, is a small spot of green. The park, left for the people by Hancock. (Photo by author)

We come to a small wooden building. Inside is a large window, overlooking a pile of dirt. Looking closer, it isn’t dirt, it is dried tar. And there are bones in it! Aisling is holding a bunch of keys as she spots the excitement on my face at seeing the bones exposed for the first time in millennia. She unlocks a door to the side, and we step through. We are leaning over the pit, on the other side of the glass. A curious father and daughter watches us from inside the wooden building. This is Pit 91, she explains. Fossils are being carefully excavated by staff and volunteers, and visitors to the park can watch them in action. The main deposit is not huge, just about three meters by two meters in the centre. The bones, darkened by the asphalt are easy to spot.

It might not look like much, but Pit 91 is revealing

It might not look like much, but Pit 91 is revealing new fossils during each excavation season. (Photo by author)

The commitment to the Page Museum to show the public the work that goes on here is inspirational. Large panels are scattered across the park, clearly and visually letting the visitors learn about the heritage of the site and the creatures that were once home here. In this park visitors are able to watch real palaeontologists excavate bones of extinct animals in front of them. I wondered how many children (and parents) watch these excavations and want to change their path to become a scientist.

Every single individual bone is carefully excavated and recorded. Today the information with each individual specimen is much more detailed than it was 100 years ago. Even the sediment is sampled for microfossils and some is sent off for pollen analysis providing more information about the climate and a detailed picture of the surrounding flora. Pit 91 has actually added over 320 new species to the fauna and flora of Rancho La Brea, including spiders, fish, amphibians, and insects. With new fossils being excavated daily, and the uncountable microfossils, a number of ‘three and a half million specimens’ at the museum is a very conservative estimate.

We talk about museum work, numbering, and the databasing, as Aisling leads us to one of the store rooms. Drawers upon drawers fill racks running the length of the store room. The sense of awe silences you as you walk in. Here, are thousands upon thousands of animals that lived not very long ago. You know you have stepped back in time. Passionately, Aisling talks about the animals that once lived here, while opening drawers: dire wolves, sabretooth cats, horses, camels, and more. So many creatures once walked on this very spot.

The author holding a bone from a dire wolf. You can see the extent of the drawers needed to store the collection. (Photo by Aisling Farrell)

The author holding a bone from a dire wolf. You can see the extent of the drawers needed to store the collection. (Photo by Aisling Farrell)

The skeletons on display in the museum are not from individuals, but composites: elements taken from several individuals and put together. I ask why it is not easy to find individuals in the excavations. “The general view of animals getting stuck and sinking into the tar is wrong,” she says. “An entire animal is rarely preserved. Think of it like fly paper. When a fly gets stuck on fly paper, the feet sink into the viscous stickiness. This is like how it was for the animals: the feet would get stuck. The body above the tar could have been eaten by predators, or even moved by the water, or weathered away. Anything below would be preserved. We rarely find full skeletons, perhaps because only a fraction of the animal got buried.”

I had always assumed the tar pits were a little like quick sand. Apparently this is a common misunderstanding. And it is why Aisling is not too fond of the flooded mine we saw earlier with the mammoth family. Fly paper. Not quicksand. The sticky tar seeps up from folded rocks deep below the surface. Some animals get trapped, and then sediment or water covers the tar. More tar seeps up, more animals get trapped, and more sediment covers it. It is often not as simple as that: sometimes the water can mix up bones and sediment.

The beautiful skeleton of a Monster Bird on display in the Page Museum. (Photo by author)

The beautiful skeleton of a Monster Bird (Teratornis merriami) on display in the Page Museum. (Photo by author)

The list of animals recovered from the site is spectacular. Along with reptiles, insects, fish and amphibians, are some glorious Late Pleistocene North American beasts: dire wolves, mastodons, mammoths, ground sloths, horses, camels, bison,  monster birds, short faced bears, American lions, and sabretooth cats (in fact two species of sabretooth cat: Smilodon fatalis and Homotherium serum). Aisling watches me as my eyes widen, and my voice goes slightly high pitched in the excitement of slowly pulling open each drawer. “Although there are lots of species, there is a bias with the fossils.” Carefully placing back a Smilodon fossil, I listen as she explains. It is also extremely likely that there will be gaps in time. “The tar is less sticky in cold weather. We see it here in winter.” Aisling never looses the passion in her voice, even as she talks about animals that are not here. The fossil deposits do not represent one continuous time period. There will be gaps. The gaps may be a couple of decades, or a couple of centuries long.

The incredible wall of around 400 dire wolf skulls on display in the Page Museum

The incredible wall of around 400 dire wolf skulls on display in the Page Museum. Author is shown for scale. (Photo taken by random museum visitor.)

The biggest project Aisling and her colleagues are working on at the minute, is to produce a detailed time line of the site. They want to use the large fossils along with the microfossils to discover how the environment has changed over this time, and how species responded to these changes.

It is an enormous project. Aisling, like her colleagues I met on my visit, know how big this is. They also know how important it is. If a detailed record going back 45,000 years can be created, it will show how animals and plants have adapted to environmental changes. And this can be used to see how animals and plants may respond to the dramatic climate changes happening now.

The gorgous sculpture of the American lion. (Photo by Author)

The gorgeous sculpture of two American lions juxtaposed with a skyscraper in the background.. (Photo by Author)

In the middle of Los Angeles is a world far away from the one we live in today. One without mobiles, or tablets. A world where the worries of modern life do not exist. A world where enormous lions stalked, and monster birds glided ahead. This was a world not that long ago. The fossils recovered from Rancho La Brea show us what an incredible landscape LA once was. What is truly magnificent is how visitors can see the work the staff and volunteers do to excavate, preserve and research the specimens. Today, over a hundred years after the first fossils were written about, Aisling and colleagues are still discovering new fact about the past, and using them to help protect our future.

Written by Jan Freedman (@JanFreedman)

An enormous thank you to Aisling Farrell, for sharing her endless enthusiasm and knowledge about the collections. Please do follow Aisling on Twitter (@AislingLaBrea)

To find out more about the Page Museum and La Brea, visit the website, or follow them on Twitter (@LaBreaTarPits)

My visit was made possible due to funding through the Jonathan Ruffer Curatorial Grants, overseen by the Arts Council (UK).

Further Reading:

Campbell, K. E. & Tonni, E. P, (1983), ‘Size and locomotion in teratorns’, Auk.  100(2).pp.390-403. [Full article]

Feranec, R. S. (2004), ‘Isotopic evidence of saber-tooth development, growth rate, and diet from the adult canine of Smilodon fatalis from Rancho La Brea’, Palaeogeography, Palaeoclimatology, Palaeoecology, 206 (3-4), 303-10. [Full article]

Figueirido, B., J. A. Perez-Claros, V. Torregrosa, A. Martin-Serra, and P. Palmqvist. “Demythologizing Arctodus Simus, the ‘Short-Faced’ Long-Legged and Predaceous Bear That Never Was.” Journal of Vertebrate Paleontology 30, no. 1 (2010): 262-75.[Full Text]

Heintzman, P. D., G. D. Zazula, J. A. Cahill, A. V. Reyes, R. D. E. MacPhee, and B. Shapiro. “Genomic Data from Extinct North American Camelops Reveise Camel Evolutionary History.” Molecular Biology and Evolution in press (June 2 2015).[Abstract]

Howard, H, (1947), ‘A preliminary survey of trends in avian evolution from Pleistocene to recent time’, Condor. 49(1). pp.10-13. [Full article]

Martin, P. S. (2007), Twilight of the Mammoths. University of California Press. [Book]

Martin, L. D., and B. M. Gilbert. “An American Lion, Panthera Atrox, from Natural Trap Cave, North Central Wyoming.” Contribs. to Geology, Univ. Wyoming 16, no. 2 (1978): 95-101.[Abstract]

McMenamin, M.A.S.; et al. (1982). “Amino acid geochemistry of fossil bones from the Rancho La Brea Asphalt Deposit, California”. Quaternary Research18 (2): 174–83. [Abstract only]

Merriam, J. C., and C. Stock. The Felidae of Rancho La Brea. Carnegie Institute of Washington Publications, 1932.[Book]

Miller, L. H, (1909), ‘Teratornis, a new avian genus from Rancho La Brea’, University of California Publications, Bulletin of the Department of Geology. 5.  pp.305-317.

Stock, C., 1930. ‘Rancho La Brea. A record of Pleistocene life in California,’ Science Series. No 37. Natural History Museum of Los Angeles.

Tejada-Flores, A. E. and Shaw, C. A. (1984), ‘Tooth replacement and skull growth in Smilodon from Rancho la Brea’, Journal of Vertebrate Paleontology, 4 (1), 114-21. [Abstract only]

van Valkenburgh, B. and Hertel, F. (1993), ‘Tough Times at La Brea: Tooth Breakage in Large Carnivores of the Late Pleistocene’, Science, 261, 456-59. [Full article]

 

 

 

Posted in American Lion, Camelops, Horse, Mastodon, Sabre tooth Cat | Tagged , , , , , , , , , , , , , , , , , , , , , , , , | 1 Comment

Giant Sloths & Sabertooth Cats

Giant Sloths and Sabertooth Cats: Extinct Mammals and the Archaeology of the Ice Age Great Basin By Donald K Grayson

 

If there is one thing I enjoy doing in my downtime, it’s reading about Pleistocene megafauna. As well as having been my job, it’s also my hobby. No surprise I’ve been lucky enough to accumulate a nice stack of books on the subject. They’ve been useful for work, and also to break open when I need something good to read. My latest purchase is “Giant Sloths and Sabertooth Cats” (hereafter GS&SC) by DK Grayson, a name that should be familiar to anyone who follows the literature of the Pleistocene, and in particular the discussion of overkill. It was with great anticipation that I first cracked open the covers of this latest book. And I was not disappointed!

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GS&SC is that rare thing- a very academic book that is also by turns funny, forthright, interesting, and human. The author gives a lot of himself to his writing and comes through as a very likeable narrator. Dry humour abounds.

The book starts with a classic case that should be well-known to fans of the Pleistocene: the Nevada State Prison footprints. This acts as a great lede for the book as it brings in many of the themes that run throughout – dating of humans in the Americas, the weirdness of ground sloths, the variety of Pleistocene fauna. There are even some great vignettes of the level of feuding between 19th century palaeontologists (including the famed O.C.Marsh) and how preconceived notions can often lead researchers agley.

mylodontracks humantrackscope

There are chapters on the flora and fauna of the great basin to set the scene. The great basin is an area centred on Nevada but bleeding into Utah, Oregon, Idaho, and California depending on who you ask to define it. The great basin is a predominantly dry ecoregion surrounded by high mountain ranges that make up its flanks, and with a variety of topographical features from desert to mountain within. It is a very varied habitat home to some iconic plant species including Joshua tree (Yucca brevifolia), creosote bush (Larrea tridentata), and bristlecone pine (Pinus longaeva, one of the longest living trees on the planet, with some ancient individuals stretching halfway back to the Pleistocene). Of course the Pleistocene fauna is incredible. The bestiary chapter in the book is one of the best and most up-to-date I’ve read. Because its difficult to appreciate the Pleistocene fauna of North America, suffused as it is with sloths, glyptodonts, and other xenarthra, without reference to its Southern neighbour, Grayson has included a great section on the South American megafauna as well. The North American megafauna is treated comprehensively with sections on important species that includes distribution maps, evolutionary history, important fossil sites, charming reconstructions (by Wally Woolfenden) and the occasional photo of fossils or animals. The text accompanying the species descriptions is great and includes latest findings from ancient DNA, radiocarbon dating, stable isotopes, proteomics and other cutting edge stuff that has been filtered from the literature. As such it is a very timely and necessary update of the classic bestiaries from Kurten & Anderson’s “Pleistocene Mammals of North America” and Martin & Klein’s “Quaternary Extinctions”.

There are some great in-depth discussions included in the species biographies. For example, the incredible Manis mastodon find is brought up and both its dating and genetic implications covered. The Manis mastodon has a rib which incredibly also has a bone projectile (also made from mastodon bone) sticking into it, which must have been thrust in from above. Here Grayson lets slip his (perfectly respectable) bias with some special pleading that the Manis mastodon projectile could have been created by bone flaking due to intraspecific combat between mastodons in musth, rather than hunting by humans.

mastodon4

Varying views of the Manis mastodon (Mammut americanum) rib and bone projectile. From Waters et al.

mastodon_04

 

This bias against human explanations for the Pleistocene extinction appears as an undercurrent throughout some very useful chapters collating radiocarbon dates for megafaunal fossils, association (or lack of it) with contemporaneous humans and histories of important fossil sites in the great basin and the people who excavated them. These details are all fascinating and expertly explained, and include several TrowelBlazers (Bertha Pallan, Hildegarde Howard). In the final chapters the author lays bare his own thesis on what caused the megafaunal collapse in the great basin and all over the new world. Firstly though, he discusses the history of Clovis points (those wonderful and terrible sculptures of flint, that can take down elephants, and did take down mammoths and mastodons). There are sidetracks down issues of hyperdisease (interesting but difficult to find in the fossil record), the Younger Dryas comet impact (nonsense beloved of uber-cranks). Grayson has long been a proponent of a climatic explanation for the extinction of the megafauna. Here, he suggests that a species specific response to glacier loss and climate change best explains the staggered (over a couple thousand years) loss of the megafauna in the Americas. He argues that the relative lack of kill sites, the staggered nature of the extinctions, and the appearance of pre-Clovis humans in the Americas discount overkill as an explanation. I am obviously in the opposite camp and think that climate had little, or at most secondary effect in the extinctions.

What is interesting to me is that Grayson spends a lot of time in chapter 4 discussing how we can be misled by last appearance dates for species based on radiocarbon dates because we are unlikely to chance upon the last individuals of a species in the fossil record if they were common (like horse) and even less likely if they are rare (like Homotherium). When discussing the relative paucity and variety of kill sites, the same arguments must apply and I don’t think this is a strong argument against human responsibility because obviously we don’t expect there to be many of these sites (simply due to taphonomy) and the small window of overlap between megafauna and humans. Even given this, we are still left, in my opinion, with a clear signal of the immensely destructive and wasteful nature of human hunting in the audacious remains of Clovis points themselves. The thousands of points we have discovered were obviously crafted for one reason and one reason only. And it aint for hunting rabbits. These Kalashnikovs of the Palaeolithic speak more eloquently than a dozen butchery sites.

Now that we know that there were pre-Clovis cultures, does this impact on the likelihood of overkill? I don’t think so. All it suggests to me is that the culture evolved to meet different needs. Megafauna that have not encountered humans before are generally naïve (like Steller’s sea cow, or Galapagos tortoises) so the first immigrants into North America probably had no need for a specialised toolkit to hunt giant sloths or glyptodonts or mastodons that they could simply walk straight up to and butcher with a pointed bone stick right where they stood. Later, either as numbers diminished or naivety was eroded, the Clovis point could have given hunters the edge.

More thought must be given to the criticism that the staggered nature of the extinctions and the disproportionate loss of large mammals does not fit with human overkill. I think we can apply Grayson’s own arguments about radiocarbon dates and final appearances to the question of a staggered extinction. As more data comes in we are likely to find a less staggered sequence. Of course not all species went extinct at the exact same moment. The unique nature of each lost species means that it would have dealt with hunting pressure in different ways. But, geologically speaking, whether the extinctions happened over a couple hundred or several thousand years, the event would count as instantaneous to any observer from the far future. I even think overkill can provide a prediction that other explanations couldn’t in this scenario. If the extinctions are truly staggered (and we would need many more C14 dates to assess this) then it should likely follow a clear pattern, with the larger species succumbing before the (relatively) smaller species. If we were to find a pattern where common smaller species were going extinct before common larger species then that would argue against hunting as a cause. Or alternatively if we find last appearance dates (after sufficient sampling) that predate even pre-Clovis cultures then we can exclude humans as the causal factor. I don’t think we are going to find this.

Throughout the book Grayson does malign the overkill arguments as circular reasoning and in particular takes some pretty serious digs at Paul Martin’s abilities as a scientist (despite also praising his influence and providing some lovely compliments on his study of coevolution of fruits and megafauna). Martin was wrong in many of the things he said and wrote but a few of the comments do come across as petty given how much he did get right.

Overall, GS&SC is a must-have for any serious student of the Pleistocene. I disagree with Grayson on many of his conclusions but there is absolutely no doubting the depth and breadth of scholarship on display between the pages and he pulls off the incredibly difficult trick of making the text funny and warm. The book makes me think that the author would be an excellent person to share a couple of pints with in the pub while discussing our mutual love of Pleistocene mammals in a passionate but respectful manner. And if that isn’t a compliment I don’t know what is.

Small mistakes- Im only really qualified to pick up on the details of the carnivores but I noticed that the map of Homotherium finds omits the Tyson Spring Cave, MN find that was recently sampled for ancient DNA. There is also some confusion (table 4.4 in the book) about the difference between North American Panthera spelaea and Panthera atrox- a distinction which is well explained earlier in the book. Basically, the kind of tiny errors that are bound to be found in a massive undertaking like this book.

Written by Ross Barnett (@DeepFriedDNA)

Further Reading:

Waters, M. R., T. W. Stafford, Jr., H. G. McDonald, C. Gustafson, M. Rasmussen, E. Cappellini, J. V. Olsen, et al. “Pre-Clovis Mastodon Hunting 13,800 Years Ago at the Manis Site, Washington.” Science 334 (2011): 351-53.[Full Text]

 

Posted in American Lion, Antilocapra americana peninsularis, Bison, Brown Bear, Camelops, Cave Lion, Cheetah, Clovis hunters, Columbian Mammoth, Extinction, Giant Beaver, Giant Ground Sloth, Glyptodon, Gompothere, Ground Sloth, Horse, Mastodon, Peccary, Pronghorn, Sabre tooth Cat, Short Faced Bear, Teratorns, Woolly Mammoth | Tagged , , , , | 1 Comment

Squishy Bear Face

“No man is an island entire of itself;

every man is a piece of the continent, a part of the main;

if a clod be washed away by the sea,

Europe is the less, as well as if a promontory were,

as well as any manner of thy friends or of thine own were;

any man’s death diminishes me,

because I am involved in mankind.

And therefore never send to know for whom

the bell tolls; it tolls for thee.”

(John Donne, 1624)

For almost 400 years, the first sentence to this poem has served as metaphor for our lives: no man (or woman) is an island. No one can prosper living alone. Every person is a part of society, and each other. We can’t be alone. We need each other.

Sorry to say it Donne, but we are actually islands. Living, thriving islands. Each one of us carries around millions of bacteria that live, reproduce and die within us. Ed Yong recently explores the splendour of the unseen ecosystems within us, in his new book I Contain Multitudes. From the outside an animal looks like a lonely, empty island. But, like all islands, they are flourishing and rich with species.

There are plenty of wonderful examples of real islands which have incredible ecosystems. Being isolated for millions of years allows some fantastical creatures to evolve. Think of the oversized, flightless pigeon, the Dodo, on the island of Mauritius, or the giant Moa species on New Zealand, and the giant lemurs on Madagascar. The list goes on. Left alone natural, and sexual, selection will create some incredibly beautiful creatures.

One island has perhaps the most unique flora and fauna around today: Australia.

Drifting alone for around 30 million years across the vastness of the oceans, it is on Australia where marsupials reign. Before the continent of Australia found itself, it was joined with many landmasses into one pretty big one called Pangaea: this was a supercontinent. With one connected area of land animals could move with relative ease from one part to another.  Marsupials first turn up in the fossil record in Northern Pangaea (North America) around 65 million years ago, they spread southwards, across South America, over Antarctica and to Australia. Through the great movements of the Earth’s tectonic plates, around 30 million years ago Australia divorced itself from the other landmasses. Carrying with it unique animals. Animals that rear their young in a pouch: the marsupials.

The supercontinent

The supercontinent Pangaea, where all the land masses were joined together as one. Australia is at the bottom right, squished with Antarctica. (Image Public Domain)

Marsupials can be found today in North and South America, but there they have been overshadowed by placental mammals (the mammals like you and I where babies are nourished in the tummy by the placenta). Australia however, until very recently, only had placental mammals which were no real competition to the marsupials: bats. This allowed the marsupials to adapt to the changing environment, and evolve into some incredible creatures. An enormous variety of kangaroos, bigger than a human, sprung across the grasslands: one kangaroo may have even walked instead of hopped. A marsupial lion ambushed its prey from trees. Giant lizards, three times the size of today’s Komodo Dragons, stalked the bush. This really was an island of lost beasts. And they were big beasts.

The Order Diprotodontia, which includes kangaroos, koalas and wombats, also includes the biggest marsupials to have ever lived. Within the sub-family Diprotodontinae was the well-known, largest marsupial, Diprotodon. There was another sub-family, Zygomaturinae, which also had another giant species, the not so well-known Zygomaturus trilobus.

You might be thinking ‘Great, another massive wombat. What’s so different to Diprotodon to have another blog post?” And rightly so. Because Zygomaturus is just another giant wombat. It isn’t even the biggest wombat. But, like the Mona Lisa, this wonderful creature is more mysterious than meets the eye.

In honour of 27 years since Quantum Leap first airing, and for ease for you, we will call our beast Ziggy. (Whoa Boy! 27 years?! Where did that go!) Although a good number of fossils of Ziggy have been found across Australia and Tasmania, this still remains a rather enigmatic creature. Perhaps the oddest part of this animal is the skull: so odd that reconstructions are somewhat comical. A good friend who suggested writing about this strange marsupial, called it ‘squishy bear face’ because of reconstructions they had seen! And it does rather look like a bear that ran into a wall.

A bear that has run in to a wall?

A bear that has run in to a wall? Nope, this is Zygomaturus trilobus. (Image Nobu Tamura. Public Domain)

Ziggy’s head is weird. Very weird. And very different to Diprotodon in many ways. The skull was huge. So big, that it was filled with sinus cavities to make it a little lighter. The teeth were complex compared to its big cousin. Complex teeth patterns makes the teeth stronger. The enamel is not just on the outside of the tooth (like our teeth) but weaved into the tooth, making it able to wear down slower. And this indicates that Ziggy could eat coarser tougher foods.

A quick sketch of Ziggy's skull. Note the strange pointy bit of bone sticking out on the nose. (Art by Jan Freedman)

A quick sketch of Ziggy’s skull. Note the strange pointy bit of bone sticking out on the nose. (Art by Jan Freedman)

One part of Ziggy’s skull in particular has caused a lot of speculation about how this creature may have lived: the peculiar bony attachment on its nose. It is a big bone attachment, and no one really knows what it was for. Some researchers have suggested Ziggy actually had a trunk. Although others point out that a trunk needs a broad surface to have the muscles attach too, like in an elephant (which Ziggy doesn’t). Other researchers suggest that there was a high nasal cavity because it had a similar lifestyle to a hippopotamus. Yet another idea is that the bony attachment held a horn, and with horns being extremely rare to fossilise, none have ever been discovered. The consensus appears to be that this big nasal bone held some pretty big upper lips: a large muscular flap of skin hung from the face – not as long or muscular for a trunk, but strong enough to manipulate objects.

The bones in the skeleton are equally strange. This was a stocky beast. The front leg bones were long, but muscle scars show they had very big muscles. Like elephants with their relatively thin leg bones, they were good walkers, but poor runners (because the thinner bones cannot take the weight and enormous stresses produced by running). These front legs also had some pretty serious claws. And again, no one really knows why. Giant claws could have been used for digging for food, or perhaps defence. As we saw with some species of giant ground sloths, big claws could have been used for digging burrows. (I should say, the possibility of Ziggy digging burrows is my own speculation. There is, as of yet, no evidence of any palaeo-burrows in Australia. And compared to giant ground sloth skeletons, the arm bones do look less robust for digging.)

Ziggy was a pretty big wombat. (Image by Jan Freedman)

Ziggy was a pretty big beast. (Image by Jan Freedman)

Fossils of Ziggy have been found all over Australia, and Tasmania. The distribution of the finds indicates that this giant wombat did prefer slight wetter environments to live in. Diprotodon was more widely distributed. The continent may have been large enough to be home to two species of large herbivores because of their different diets: Ziggy happily chomping through tough vegetation, while Diprotodon was at home enjoying luscious, softer green leaves.

The fossil finds of Ziggy and other Pleistocene giants. Notice Ziggy's distribution is close to the coast. (Image from Quaternary Extinctions. page 264).

The fossil finds of Ziggy and other Pleistocene giants. Notice Ziggy’s distribution is close to the coast. (Image from Quaternary Extinctions. page 264).

Ziggy and her kind were around for over 15 million years, which is a pretty long time for any Sub-Family. Her success was due to her isolation. Island living animals have the time to adapt to the changing environments on that island, and the other inhabitants. So when a new animal appears, it can cause havoc. This happened when North and South America joined together and animals from both land masses moved up and down, entering new environments, and wiping out species. And something happened in Australia too. Around 35,000 years ago Ziggy vanished. She clung on in small populations on Tasmania. But by around 24,000 years ago, Ziggy vanished forever.

Her disappearance coincides with the arrival of humans around 50,000 years ago. However, with these early Australian living out in the open, there are few sites showing clear evidence of hunting. (This is compared to the abundant fossils found in caves in Europe and America where the remains are more protected from the outside world.) As a little aside, thanks to Lee Constable, I recently discovered that wombats will pee if their bottoms are tickled. Obviously, the first thing I thought when I saw this, was did the first Australians try something like this with Ziggy? Tickling a giant wombat’s bottom would have been an interesting thing to witness.

At around the time Ziggy and her kind started to disappear, the world was changing. Sea levels were lower as water was trapped in the great ice sheets in the northern hemisphere. Worldwide, the climate was drier. Australia was moving slowly northwards, getting warmer, and beginning to lose its luscious tropical rain forests. As with many of the great Pleistocene extinctions, there was likely to be more than one factor contributing to the end of this species. Ecological stresses would have put intense pressure on small groups. Coupled with a new carnivore on the scene, our squishy faced bear vanished forever.

Postscript:

“We are all islands”? “He disagrees with Donne?!” Now, dear reader, you may be wondering where my romantic side has gone. For those who have followed this blog for the last two and half years, you will know I am a romantic at heart. And there is nothing wrong with romanticising science so long as the reader comes away swoon by the gorgeous key facts. I do believe 400 years ago, Donne had it right. No one should be alone. The ocean we live in each day is full of other islands. We may go along drifting, bumping into other islands every now and again. Perhaps we let them float by. Maybe we hold onto them. Even with millions of people around us, our little lives can sometimes seem as big, and empty, as an ocean. Life is short. Don’t let something special drift by.

Written by Jan Freedman (@JanFreedman)

A special thanks to Gilbert Price, vertebrate paleoecologis at The University of Queensland, for his help with gathering information for this post.

Further reading:

Black, K. H., et al. (2010). ‘First comprehensive analysis of cranial ontolgeny in a fossil marsupial – from a 15 million year old cave deposit in Northern Australia.’ Journal of Vertebrate Paleontology. 30(4). pp.993-1011. [Abstract only]

Johnson, C. (). Australia’s Mammal Extinctions, a 50,000 year history. Cambridge University Press. [Book]

Martin, P. & Klein, R. G. (Eds) (1989). Quaternary extinctions. University of Arizona Press. [Book]

McNamara, K. & Murray, P. (2013). Prehistoric Mammals of Western Australia. Western Australian Museum. [Book]

Megirian, D., et al. (2010). ‘An Australian land mammal age biochronolgical scheme.’ Paleobiology. 36(4). pp.658-671. [Full article]

Meredith, R. W., Westerman, M., & Springer, M. S. (2009). ‘A phylogeny of Diprotodonta (Marsupialia) based on sequences of five nuclear genes.’ Molecular Phylogenetics and Evolution. 51. pp.554-571. [Abstract only]

Pate, F. D., et al. (2002). ‘Last recorded evidence for megafauna at Wet Cave, Naracoorte, South Australia. 45,000 years ago.’ Australian Archaeology. 54. pp.53-55. [Abstract only]

Price, G. (2008), ‘Taxonomy and palaeobiology of the largest‐ever marsupial, Diprotodon Owen, 1838 (Diprotodontidae, Marsupialia).’ Zoological Journal of the Linnean Society 153.2. 369-397. [Abstract only]

Prideauz, G. J., et al. (2010). ‘Timing and dynamics of Late Pleistocene extinctions in southwestern Australia.’ Proceedings of the National Academy of Sciences of the United States of America. 107(51). pp.22157-22162. [Abstract only]

Price, G. (2012), ‘Plio-Pleistocene climate and faunal change in central eastern Australia.’ Episodes-Newsmagazine of the International Union of Geological Sciences 35. 1  160.

Turny, C. S.M., et al. (2008). ‘Late-surviving megafauna in Tasmania, Australia, implicate human involvement in their extinction.’ Proceedings of the National Academy of Sciences of the United States of America. 104(43). pp.12150-12153. [Abstract only]

Posted in Zygomaturus | Tagged , , , , , | 5 Comments

Turtle Power

In the canonical tale, Big Chuck D’s visit to the Galapagos was a “Eureka!” moment, where he instantly worked out his theory of evolution by natural selection after observing the different species of finches on the archipelago’s varying islands. Almost nothing about this tale is true. Darwin’s collecting in the Galapagos was haphazard and unlabelled; he had to retrospectively fill in the blanks on his specimens when he got back to England with the help of shipmates. The idea of natural selection did not appear fully formed in Charlie’s brain but percolated there over many years at Down House, coupled with his continual tinkering and experimenting. The idea of different forms inhabiting different islands was something discussed on the Galapagos during his visit. But it was the giant tortoises that were the subject.

“My attention was first called to this fact by the Vice-Governor, Mr. Lawson, declaring that the tortoises differed from the different islands, and that he could, with certainty tell from which island any one was brought.”

The  species of Chelonoidis nigra found in the Galapagos and Aldabrachelys gigantea of the Seychelles and Aldabra are the only surviving giant tortoises (and we very nearly lost them too). Go back a few hundred years and there were various, now extinct, species of giant tortoise on Madagascar and the Mascarenes. Back in the Pleistocene we had something even more wonderful (quelle surprise!) in the mellifluous meiolaniids. These giants were the convergent herptile version of the glyptodonts and ankylosaurs that had independently hit upon a similar niche.

The

The distribution of giant tortoises. Green=extant, Red=meiolaniids. Map from http://www.d-maps.com

tortoise

Wild Santa Cruz tortoise Chelonoidis nigra porteri. Image author’s own.

Author

Observing megafauna at Charles Darwin Research Centre, Santa Cruz, Galapagos. Image author’s own.

When I visited the Galapagos I had the intense pleasure of hanging out at the Charles Darwin research centre and chilling with some of the rescued giant tortoises that reside there. It really was special just being able to sit and watch a giant wild creature, naïve to the special threat that humans usually pose, and happy to go about its feeding without fear. Even if it had wanted to attack me, the worst it could probably inflict was a serious gash from its keratinous beak. The meiolaniids, on the other hand, basically scream out from every apomorphy “back off, man”. Shell? Spikes. Skull? Oh my god, so many spikes. Tail? You bet there were spikes.

niolamia

Skull of Niolamia argentina from Patagonia. Public Domain image vie Wikimedia Commons

meiolania_platyceps

Reconstructed skeleton of Meiolania platyceps from Lord Howe Island at the AMNH. Image by Claire Houck via Wikimedia Commons

KONICA MINOLTA DIGITAL CAMERA

Close up on the armoured tail of Meiolania platyceps from Lord Howe Island Maritime Museum. Image by Fanny Schertzer via Wikimedia Commons

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Wonderful public domain image of a meiolaniid. Via Wikimedia Commons

The Meiolanidae are known from the southern continents that made up Gondwanaland, particularly South America and Australia. Two of the best known species from Oz are Meiolania oweni (now Ninjemys oweni, more on this later) found in Queensland, and Meiolania platyceps, known from Lord Howe Island. Lord Howe Island is a pretty tiny chunk of volcano way out in the middle of the south pacific, hinting that this was a very widespread family of hero-turtles. In fact, meiolaniid fossils have been found on New Caledonia, Vanuatu, and other Polynesian islands.

lord_howe_island

Lord Howe Island: Tiny and in the middle of nowhere between Australia and New Zealand. Via Wikimedia Commons

The history of their discovery involves some very famous Victorian naturalists. Richard Owen first erroneously identified a mixed assemblage of bones from Australia that included Meiolania, as Megalania prisca the giant monitor lizard. “Darwin’s Bulldog” T. H. Huxley then set him right in an appropriately sassy publication with the putdown “What Megalania prisca may be I do not pretend to say” <sips tea>. In South America, Florentino Ameghino, Francisco Moreno and Santiago Roth (who were involved with excavation of Mylodon cave in Patagonia) described Patagonian Meiolania material (now known as Niolamia argentina). Moreno even published descriptions of Meiolania/Niolamia in a paper with a description of the famous Mylodon darwinii skin from Ultima Esperanza. Niolamia as a taxonomic entity seems to result from the perils of a 19th century science that relied on postal communication and deciphering cursive.

w

A cartoon of Richard Owen(L) and Thomas Huxley(R) satirising their well-known antipathy towards each other in matters of science. This is referred to in Charles Kingsley’s “The Water Babies” from where this image by Linley Sambourne is taken. Via Wikimedia Commons

In terms of when this living wartortle actually roamed, the fossils give us the answer. The specimens from mainland Australia are Pleistocene in age and coeval with Diprotodon, Thylacoleo, Megalania, and the other marsupial megafauna. The Lord Howe island material is certainly Pleistocene and possibly even Holocene in age. Material from New Caledonia has been found in layers dated to just 1,720±70 years, but could have been redeposited. However, the most interesting dating comes from Vanuatu. Here dozens of bones of ?Meiolania damelipi found in the lowest midden layers of a Lapita cemetery were only 2890-2760 years old. This corresponds exactly with the first evidence for people on these islands. Like the ground sloths, woolly mammoths and other vanished taxa, it seems incontrovertible that humans first wiped out the continental populations before finding their isolated island outposts and slaughtering them there too.

If only Michelangelo, Donatello, Raphael, and Leonardo could have taught the meiolaniids some self-defense! But wait. I referred earlier to the taxonomic reshuffling that turned Meiolania oweni into Ninjemys oweni and didn’t explain why. Prolific meiolaniid author Eugene Gaffney has devoted a lifetime to studying these awesome creatures and in his expert opinion the Pleistocene Australian material is generically distinct from the later Lord Howe material. He needed to erect a new genus name and I leave his most bodacious explanation for the etymology of Ninjemys below.

“Etymology: Ninja in allusion to that totally rad, fearsome foursome, epitomizing shelled success; emys, turtle.”

Cowabunga!

Written by Ross Barnett (@DeepFriedDNA)

Further Reading:

Darwin, C. R. The Voyage of the Beagle. New York: Penguin, 1839.[Full Text]

Gaffney, E. S. “The Cervical and Caudal Vertebrae of the Cryptodiran Turtle, Meiolania platyceps, from the Pleisocene of Lord Howe Island, Australia.” American Museum Novitates, no. 2805 (1985): 1-29.[Full Text]

———. “The Cranial Morphology of the Extinct Horned Turtle Meiolania platyceps, from the Pleistocene of Lord Howe Island, Australia.” Bulletin of the American Museum of Natural History 175, no. 4361-480 (1983).[Full Text]

———. “Ninjemys, a New Name for “Meiolaniaoweni (Woodward), a Horned Turtle from the Pleistocene of Queensland.” American Museum Novitates, no. 3049 (1992): 1-10.[Full Text]

———. “The Postcranial Morphology of Meiolania platyceps and a Review of the Meiolaniidae.” Bulletin of the American Museum of Natural History, no. 229 (1996): 165.[Full Text]

Gaffney, E. S., J. C. Balouet, and F. De Broin. “New Occurrences of Extinct Meiolaniid Turtles in New Caledonia.” American Museum Novitates, no. 2800 (1984): 1-6.[Full Text]

Huxley, T. H. “Preliminary Note on the Fossil Remains of a Chelonian Reptile, Ceratochelys sthenurus, from Lord Howe’s Island, Australia.” Proceedings of the Royal Society of London Series B-Biological Sciences 42 (1887): 232-38.[Full Text]

Moreno, F. P. “Note on the Discovery of Miolania and of Glossotherium (Neomylodon) in Patagonia.” Geological Magazine Decade IV. Volume VI, no. IX (1899): 25-29.[Full Text]

Owen, R. “Description of Some Remains of the Gigantic Land-Lizard (Megalania prisca, Owen) from Australia. Part Ii.” Philos Trans R Soc Lond B Biol Sci 171 (1880): 1037-50.[Full Text]

———. “On Parts of the Skeleton of Meiolania platyceps (Owen).” Philosophical Transactions of the Royal Society B-Biological Sciences 179 (1888): 181-91.[Full Text]

Sterli, J., and M. S. de la Fuente. “Re-Description and Evolutionary Remarks on the Patagonia Horned Turtle Niolamia argentina Ameghino, 1899 (Testudinata, Meiolaniidae).” Journal of Vertebrate Paleontology 31, no. 6 (2011): 1210-29.[Abstract]

White, A. W., T. H. Worthy, S. Hawkins, S. Bedford, and M. Spriggs. “Megafaunal Meiolaniid Horned Turtles Survived until Early Human Settlement in Vanuatu, Southwest Pacific.” Proceedings of the National Academy of Sciences of the United States of America 107, no. 35 (2010): 15512-16.[Full Text]

Posted in Meiolania | Tagged , , , , , , , , , , , , , , , , , , , | 2 Comments

Staying put: the what, when, and how of the first farmers

We’ve all thought about making lifestyle changes at some point. Joining a running group. Going on a diet. Stopping smoking. So did our hunter-gatherer ancestors. They made what would be perhaps one of the greatest lifestyle changes in the history of our species: they started what would become farming. And it caught on, having vast implications for the world we know today.

For most of our time on earth humans have practised what is known as a hunter-gathering lifestyle; a nomadic lifestyle where food, largely meat, is obtained and shared through foraging. Although there are still some groups practising this mode of subsistence, in multiple parts of the world individuals and populations underwent a massive paradigm shift to a new way of life. From the end of the Pleistocene humans began to settle; we began to cultivate the land, to herd animals and drink milk continuously into adulthood. No longer was supply in shortage but instead in surplus.

A comparative timeline of the origins of agriculture and associated technologies. Drawn by Dr. Chris Stevens as part of the ComPAg project.

A comparative timeline of the origins of agriculture and associated technologies. Drawn by Dr. Chris Stevens as part of the ComPAg project.

This way of acquiring food, and by “owning” the land they lived on, spawned social hierarchy, currency and many other socio-political and cultural changes. It was the event that perhaps changed the very nature of our species. This process occurred at least three times around the world: the Middle East, Latin America and China. Farming not only profoundly changed the face of humanity but also changed the terms of humanities relationship with the world. But what drove this change? Researchers are working hard to try and understand why this happened, why it was so successful and how it spread.

Some of the earliest evidence of farming anywhere in the world has been found in the Fertile Crescent (south eastern Turkey, north eastern Iraq, and western Iran); a crescent shaped piece of moist, cultivable land situated between the arid Arabian Desert to the South and the Armenian highlands to the North. Archaeological sites in the region tell stories of rich civilisations with evidence of early crop cultivation and crop storage. For example, the Neolithic site of Chogha Golan (Ilam Province, present-day Iran) is known for a striking record of the cultivation of wild plants and some of the earliest appearances of domesticated crop species such as wheat and barley. Stone tools from the site include mortars, pounders, pestles and grinding slabs for processing grains and other foods. There is also strong evidence for the presence of domesticated livestock in the region including goats, sheep, pigs and cows. Rather importantly, it is also thought to be one of the first places we brewed beer. Based on the archaeological record it appears that from this fertile region farming spread through Turkey, Greece and Cyprus by 6500BCE, and then spread through the Balkans, Central Europe and the Mediterranean eventually reaching Britain around 4000BCE. As a historical process this change is called the Neolithic revolution (the term Neolithic relates to the adoption of agriculture and it’s distinct culture).

Trench at the Neolithic site of Chogha Golan at the foot of the Zagros Mountains, Iran.

Trench at the Neolithic site of Chogha Golan at the foot of the Zagros Mountains, Iran.

By the rate of spread you might think that farming was a sensible idea with immediate rewards. But what remains a puzzle is that at least to begin with, farming doesn’t appear to be that beneficial. Imagine, as a hunter-gatherer, that you decided to try a new strategy and stop moving; to settle in one place and to take up a lifestyle that would become what we now know as farming. As life goes on you begin to face new challenges; living in large groups of people, close to animals, accumulating stinky bio-waste and rubbish. Disease begins spreading between you, between your animals and between your crops. The good wheat you’ve worked hard to grow and store has become ridden with pests. You’re working harder for longer hours with less reward. You think to yourself, tired and shivering with fever, was this really worth it?

So if it wasn’t immediately a good strategy, why did those first hunter-gatherers who started farming keep doing it and why did it catch on? One line of research is exploring the different factors that caused our hunter-gatherer ancestors to make the switch. Using mathematical models it is possible to theoretically simulate various situations and conditions and extrapolate what implications they may have. Using a model-based approach is particularly important in this scenario because we are investigating events that happened a long time ago: you can’t go back in time and investigate using the standard tools an anthropologist might today. Models are also useful where lots of independent factors are interacting in a way that is difficult to understand using intuition, as is the case here.

Recent research exploring the historical dynamics of farming suggests that the development and persistence of farming is most probable in a model where the first hunter-gatherers to start farming were in small groups of a handful or so individuals. They also conclude that ownership of land (property rights) is an important factor and that in some instances it is possible for a farming way of life to persist even if it results in less food than you might get from hunter-gathering – not intuitive at all! So it appears farming may initially have grown from small groups of individuals trying out new methods but where the idea of land ownership was important.

As we’ve said this shift created a corresponding need for new technologies and with it a culture change. Some key definers of Neolithic life include developments in architecture, tools, figurines and jewellery. Pottery was also important, with large jars created to store excess grain becoming more decorated as the Neolithic persisted, allowing many archaeological sites to be defined chronologically based on the kinds of pottery vessels discovered. Burial practice and mythology also changed shown through the appearance of ceremonial monuments including the famous Stonehenge. And of course monuments of this kind only make sense if you live a sedentary life-style. Why bother creating such a spectacle if you have to move on in search of the next meal soon after?

The world famous monument of Stonehenge was erected in the Late Neolithic around 2500BCE.

The world famous monument of Stonehenge was erected in the Late Neolithic around 2500BCE.

Farming didn’t just change us culturally but also genetically and so analysis of DNA is another important tool in exploring this transition. The debate that continued for many years was how farming spread in to Europe from the Near East. Did plucky groups of inventors develop this new way of life and it was swiftly copied throughout Europe by way of word of mouth (the “cultural diffusion” model)? Or did those first farmers migrate to new areas with their novel technology displacing and replacing the existing hunter-gatherer groups they met along the way (“demic diffusion” model)? Although these models should not be regarded as mutually exclusive they do offer a testable hypothesis for geneticists.

One way geneticists have been trying to answer these questions is using DNA extracted from remains of some of the very first European farmers (ancient DNA). By comparing the DNA of early farmer individuals to the DNA of people alive today these competing ideas can be explored. It might seem simple but it turns out that working with very old DNA is fraught with difficulties. When an organism is alive, DNA repair enzymes work hard to maintain the integrity of DNA. After death however these enzymes stop working and the DNA immediately begins to degrade breaking up strands into smaller and smaller pieces and changing the genetic code. This process continues over time and is sped up in warm and wet climates. What’s more, particularly when working with human ancient DNA, there is a high risk of contamination. When the degraded DNA you are trying to work with closely resembles that of you, the researcher in the lab, the excitement of your new discovery is quickly quashed by the realisation you have cross-contaminated your sample! That being said, with improved technology such as next generation sequencing, the field of ancient DNA research is expanding rapidly. One key development was the discovery that the petrous bone of the inner ear contains a startling amount of DNA, hidden, relatively untouched by contaminating bacteria and somewhat immune to the effect of warm temperatures, lying deep within the skull.

Human skeleton from an archaeological excavation in Northern Greece (Paliambela Excavation Project Archive - credit K. Kotsakis and P.Halstead).

Human skeleton from an archaeological excavation in Northern Greece (Paliambela Excavation Project Archive – credit K. Kotsakis and P.Halstead).

DNA extracted from the petrous bone of human remains found in Anatolia and Greece (some of the earliest farming sites) has been used to directly test the hypotheses of demic versus cultural diffusion models. By comparing the DNA of Europeans alive today with DNA from these very early Anatolian and Greek farmers it has been shown that all Neolithic farmers look genetically similar to present day Southern Europeans and that the patterns of shared ancestry extend all the way back to North-West Anatolia. This suggests a wide-spread migration and replacement by farmer individuals moving into Europe and that the change to farming in Europe was mediated by moving people rather than primarily by the spread of ideas.

The story gets more complicated if we consider the genetic status of the first farmer individuals beyond Anatolia. Despite the challenge of the warm climate of the Near East ancient DNA has recently been obtained from human remains from the heart of the Fertile Crescent – those individuals that lived right at the very dawn of farming. Recent work involving three research groups compared DNA from very old human farmer remains found in Fertile Crescent to DNA from other early farmers, late hunter-gatherers and modern individuals. Very strikingly, considering the genetic status of individuals from this region, it was found that there were in fact genetically distinct groups of early farmers occupying this region.

Genetic analyses showed that these early Iranian farmers were not the ancestors of farmers in Europe and instead closely resemble modern day groups from Armenia, Pakistan and India. What is more, ancient DNA samples from early farmers in the Southern Levant (Israel and Jordan) were different again, likely spreading their farming culture southwards in to East Africa. It seems this revolution was brought about by groups of people who were extremely genetically different. These new finds will direct researchers to look for more archaeological sites in order to better characterise how these distinct groups have contributed to present day genetic diversity and what this means for how farming spread to other parts of the globe.

Ancient DNA from human remains in Iran (blue) and Anatolia (red) show very different genetic affinities to modern day populations suggesting multiple origins for farming and evidence of an eastwards expansion (adapted from Broushaki et al. 2016).

Ancient DNA from human remains in Iran (blue) and Anatolia (red) show very different genetic affinities to modern day populations suggesting multiple origins for farming and evidence of an eastwards expansion (adapted from Broushaki et al. 2016).

But we don’t just have to look at humans. Farming involved the domestication of crops and animals and this leaves its own genetic signature. One active line of enquiry is analysing archaeological remains and performing genetic analyses comparing the DNA from present day domestic species to Neolithic plant and animal remains. Barley, for example is largely regarded as a founder crop of Neolithic agriculture. Recent work, which extracted the genome sequences of five 6,000 year-old barley grains (the oldest plant genome reconstructed to date) discovered at Yoram Cave in Israel, found that these first domesticated barley grains are surprisingly genetically similar to modern day domestic barley but strikingly different genetically to the wild forms grown in the Levant today. This suggests that barley was indeed domesticated within the upper Jordan Valley of the Fertile Crescent, which agrees well with known archaeological sites.

The same can also be said of animals. The Zagros region of Iran has largely been regarded as the site of domestication of the goat from the wild Bezoar goat to a domesticate form more like we know today. Ancient DNA analysis, this time of mitochondrial DNA (DNA passed down exclusively through the female line) from goat remains, reveals that this region is the likely progenitor of the domestic goat and that the mitochondrial DNA lineage of goats from this region is the same as that responsible for population expansions into West Iran, the South Caucasus and beyond.

Dry preservation of plant remains from excavations (left) and a well preserved, desiccated barley grain found at Yoram cave (right)

Dry preservation of plant remains from excavations (left) and a well preserved, desiccated barley grain found at Yoram cave (right)

Neolithic goat jaw bone from Göytepe (Image courtesy of Nagoya University).

Neolithic goat jaw bone from Göytepe (Image courtesy of Nagoya University).

So farming was adopted multiple times in the Fertile Crescent by small groups of hunter-gatherers that were remarkably genetically distinct from one another. The spread of farming involved the movement of people who took with them new domesticated forms of plants and animals as well as new technologies, social organisations, culture and ideas. And it was this that profoundly changed the world in which we live today.

Written by Lucy van Dorp (@LucyvanDorp)

Edited by Jan Freedman (@JanFreedman)

Further Reading:

Broushaki, M.G Thomas, V. Link et al. (2016). ‘Early Neolithic Genomes from the Eastern Fertile Crescent’. Science. 353, 6298. pp.499-503. [Abstract only]

Dounias, & A. Froment. (2011). ‘From foraging to farming among present-day forest hunter-gatherers: consequences on diet and health.’ International Forestry Review. 13, 3. pp.294-304. [Abstract only]

Gallego Llorente, S. Connell, E.R. Jones et al. (2016). ‘The genetics of an early Neolithic pastoralist from the Zagros, Iran.’ Scientific Reports. 6. p.31326. [Full article]

Hofmanova, S. Kreutzer, G. Hellenthal et al.,(2016). ‘Early farmers from across Europe directly descended from Neolithic Aegeans.’ PNAS. 113(25). pp.6886-91. [Full article]

Gallagher, S. Shennen, & M.G. Thomas, (2015). ‘Transition to farming more likely for small, conservative groups with property rights, but increased productivity is not essential.’ PNAS. 112(46). pp.14218-23. [Abstract only]

Kadowaki, K. Ohnishi, S. Arai, et al.,(2016). ‘Mitochondrial DNA Analysis of Ancient Domestic Goats in the Southern Caucasus: A Preliminary Result from Neolithic Settlements at Göytepe and Hacı Elamxanlı Tepe.’ International Journal of Osteoarchaeology. pp.1099-1212. [Abstract only]

Lazaridis, D. Nadel, G. Rollefson et al., (2016). ‘Genomic insights into the origin of farming in the ancient Near East.’ Nature. 536. Pp.419-424. [Abstract only]

F.H. Mazdarani, M.T. Akbari, R.M.N. Fard et al., (2014). ‘Molecular dentification of Capra hircus in East Chia Sabz, an Iranian pre-pottery Neolithic site, central Zagros, based on mtDNA.’ The Journal of Animal & Plant Sciences. 24(3). pp.945-950. [Full article]

Mascher, V.J. Schuenemann, U. Davidovich et al., (2016). ‘Genomic analysis of 6,000-year-old cultivated grain illuminates the domestication history of barley.’ Nature Genetics. 48. pp.1089-1093. [Abstract only]

Mathieson, I. Lazaridis, N. Rohland et al., (2015). ‘Genome-wide patterns of selection in 230 ancient Eurasians.’ Nature. 528. pp.499-503. [Abstract only]

Omrak, T. Gunther, C. Valdiosera et al. (2016). ‘Genomic Evidence Establishes Anatolias the Source of the European Neolithic Gene Pool.’ Current Biology. 26(2). pp.270 [Abstract only]

Riehl, M. Zeidi, & N. J. Conard, (2013). ‘Emergence of Agriculture in the Foothills of the Zagros Mountains of Iran.’ Science. 341. pp.65–67. [Abstract only]

Willcox. (2013). ‘The Roots of Cultivation in Southwestern Asia.’ Science. 341. pp.39-40.[Abstract only]

Posted in Homo sapiens | Leave a comment

Disappearing into the heavens

Some years ago I witnessed a dinosaur attack. There was a flash of brown, then a thud. It was over in a second. Sharp powerful claws gripped its prey, pinning it against the ground. Then it began to feast. I never saw it coming. The wood pigeon never saw it coming.

The beautiful light grey bird was bobbing along quite happily in my garden, picking up seeds fallen from my bird feeder. I was watching it move: that classic bob of the head in sync with those scaly legs and claws. Then, out of nowhere, a blur. A sparrow hawk had shot out of the sky, landing on the pigeon, flattening it to the ground. Perhaps stunned, perhaps not, the pigeon had no chance. The sharp curved, super sharp beak of the sparrow hawk began to pluck away feathers so it could gorge on the flesh beneath.

The reign of the dinosaurs has never left us. Humans have witnessed similar dinosaur killings for millennia. But none on such as scale as this beast you are about to read about.

The beautiful Eurasian Sparrow Hawk (Accipiter nisus). (Image by Christian Knoch)

The beautiful Eurasian Sparrow Hawk (Accipiter nisus). (Image by Christian Knoch. Public Domain.)

Birds, the only surviving group of dinosaurs, total nearly 10,000 different species. Aside from fish they are the most successful group of vertebrates, living on every single continent. And they are incredibly diverse. Some have lost use of their wings, to return to land living. Others have enormous webbed feet and become expert swimmers. Sharp beaks tear flesh. Thick beaks crush nuts. Thin beaks pluck worms. Elaborate feathers seduce. This is an amazing group of animals.

Over the last 66 million years, since the extinction of their relatives, there have been some spectacular species. None more so than the giant flightless birds. There was the long reign of the giant terror birds, who stomped on the planet for over 60 million years. There was the frightful European Gastornis, from around 55 million years ago to around 35 million years ago. Big birds even roamed Australia. These were all very big. And all would have been bloody terrifying to see in the flesh. But none would have killed as that sparrow hawk did.

A giant bird (Image by Jan Freedman)

The American Terror Birds were enormous. (Image by Jan Freedman)

There were giant fliers who may fit the bill (excuse the pun). A giant relative to the buzzard, mis-named the Woodward ‘Eagle’, was massive compared to today’s buzzards (or eagles) alive today. The enormous, aptly named Monster Birds would have dwarfed condors alive today. These were both gliders; hovering on warm thermals, searching for that carcass. One extinct giant hunted like our sparrow hawk. Only this beast’s prey was much, much larger than wood pigeons.

New Zealand was home to just a small number of mammals, all of which were bats. This left this dramatic landscape open for other groups to exploit and exploit it the birds certainly did. There was the wonderfully named Mysterious Starling, the Laughing Owl, the Long-billed Wren, the Stout-legged Wren, and even a species of penguin. Isolated for millions of years, the islands of New Zealand were evolutions’ aviaries. With no mammals on the islands (except for three species of bat), birds had free reign of many new niches. There were also many species of Moa: huge flightless, grazing birds that only became extinct in the 1600s.

A reconstruction of the upland Moa. (Megalapteryx sp.) from Baron Rothschild’s book “Extinct Birds”. (Public Domain)

A reconstruction of the upland Moa. (Megalapteryx sp.) from Baron Rothschild’s book “Extinct Birds”. (Public Domain)

Carnivores evolved alongside the herbivores: large harriers (Eyles Harrier), and several types of hawks. Yet, none of these came close to the ultimate New Zealand carnivore: Te Hōkioi.

“This bird, Hōkioi was seen by our ancestors. We…have not seen it – that bird has disappeared nowadays. The statement of our ancestor was that it was a powerful bird, a very powerful bird. It was a very large hawk. Its resting place was on the top of mountains; it did not rest on the plains…Its colour was red and black and white. It was a bird of (black) feathers, tinged with yellow and green; it had a bunch of red feathers on top of its head.” (Maori Legend)

Around 700 years ago, the first humans settled on New Zealand. They saw this bird while it was alive. And, today it lives on in their stories.

Hōkioi was an Eagle. An enormous eagle. The heaviest eagle so far discovered. Outrageously enormous claws first excavated in 1871, gave this beast the name Harpagornis moorei: ‘harpa’ meaning grappling hook, and ‘gornis’ meaning bird. (The species, moorei was given after the landowner were the fossils were first found, George Moore.) Harpagornis, also called Haast’s Eagle after its discoverer, was huge. Females weighed up to around 15kg and males up to 11.5kg: compare this to just a meagre 4kg for a male and 6.6kg for female golden eagles. With wingspans of just 3m, just a fraction longer than a golden eagle, you may think that Harpagornis was oddly disproportionate. It was, however, perfectly endowed for its lifestyle. It was a hunter. An active, surprisingly agile hunter.

Just like a sparrow hawk, Harpagornis flew through forests and scrublands, with relative ease. With a shorter wingspan, it would be able to manoeuvre with relative ease when it went for the attack. Incredible fossil remains tell us what the Haast’s Eagle was preying on. Several Moa pelvis remains have very large holes in them: holes made by the powerful talons of Harpagornis. From high up vantage points, Harpagornis would launch itself, gliding effortlessly through forests. It would land with such a force that its claws pierced through the Moas’ bones. This makes my sparrow hawk look like a pussy cat.

Enormous holes in the pelvis of a Moa. Made by the gigantic talons of Harpagornis.

Enormous holes in the pelvis of a Moa. Made by the gigantic talons of Harpagornis. (Image from Holdaway & Worthy, 2008)

This bird got big quick. It evolved from smaller eagles around 1 million years ago. It’s a classic example of Island Gigantism, where animals isolated on islands have abundant food allowing them to grow to pretty big sizes. (The dodo is a good, if not often recognised, example of this.) With little competitors, and prey as huge as the Moa, these raptors were able to grow to extraordinary sizes.

Harpagornis was

Harpagornis was a massive eagle. Humans would have seen them in action.

What is truly fascinating, and is true for so many of our Twilight Beasts, is that humans saw them alive. The Maori may have watched in awe as Harpagornis took down a Moa: a true clash of the Titans. This magnificent bird was captured by the Maori in cave art, showing significance in their lives.

from ‘Cave of the Eagle’, in the Canterbury district.

Beautiful cave art from ‘Cave of the Eagle’, in the Canterbury district, New Zealand. (Image by Amanda Symon, Ngai Tahu Maori Rock Art Trust. Reproduced with permission.)

Even the name, Te Hōkioi, gives us a tantalising glimpse of what this extinct animal sounded like. It appears in Maori legend:

“Its rival was the hawk. The hawk said it could reach the heavens: the Hōkioi said it could reach the heavens to the hawk; there was contention between them.

The Hōkioi said to the hawk, “what shall be your sign?” The hawk replied “kei” (the peculiar cry of the hawk).

Then the hawk asked, “what shall be your sign?” The Hōkioi replied, “hokioi-hokioi-huu.” These were three words.” (Maori Legend)

Until just around 400 years ago, Harpagornis was swooping through the forests, like a gigantic sparrow hawk. It’s extinction is something familiar and obvious, but still something we fail to learn from today. As people began to settle on New Zealand, they expanded, altering the habitat as they went. The change in habitat hit the large flightless Moa hard, more so because they were also hunted by the Maori for food. The Moa became extinct around 1600. With their main food source gone, the Haarst Eagle vanished.

“They then flew and approached the heavens. The winds and the clouds came. The hawk called out “kei” and descended, it could go no further on account of the winds and the clouds, but the Hōkioi disappeared into the heavens.” (Maori Legend)

Around us the world is changing. Forests are vanishing. Habitats being destroyed. Oceans polluted. Climate is more erratic. Many species we know will be lost because of our lack of respect for nature. A species does not vanish alone. It is part of a complex web of life. When one species is gone, many, many more will sadly, silently, disappear into the heavens.

Written by Jan Freedman (@JanFreedman)

A special thank you to Amanda Symon at the Ngai Tahu Maori Rock Art Trust for allowing us to use the beautiful rock art painting. Please do have a look at their website for more information about New Zealand’s incredible rock art.

Further Reading:

Alcover, J. A & McMinn, M. (1994). ‘Predators of vertebrates on Islands.’ BioScience. 44 (1). pp. 12-18. [Abstract only]

Best, E. (1982), Maori Religion and Mythology. Part 2. P.D. Hasselberg, Wellington. pg. 563 [Full text]

Brathwaite, D. H. (1992).’ Notes on the weight, flying ability, habitat and prey of Haast’s Eagle (Harpagornis moorei)’. Notornis. Ornithological Society of New Zealand. 39 (4): 239–247. [Full article]

Bunce, M. et al. (2005). ‘Ancient DNA provides new insights into the evolutionary history of New Zealand’s giant eagle.’ PLoS Biology. 3 (1): e9. [Full article]

Haast, J. (1872). “Notes on Harpagornis Moorei, an Extinct Gigantic Bird of Prey, containing Discussion of Femur, Ungual Phalanges and Rib”. Transactions and Proceedings of the New Zealand Institute.  4. New Zealand Institute. pp. 193–196. [Full article]

Holdaway, R. N., M. E. Allentoft, C. Jacomb, C. L. Oskam, N. R. Beavan, and M. Bunce. (2014). “An Extremely Low-Density Human Population Exterminated New Zealand Moa.” Nat Commun 5. pp5436. [Abstract only]

Holdaway, R. N., & Worthy, T. H. (2008). ‘The Late Quaternary Avifauna’. In Winterbourne, M.J et al. ‘The natural history of Canterbury’. 3rd Edition. Canterbury University Press and Manaaki Whenua Press. Christchurch. [Book]

Perry, G. L. W., A. B. Wheeler, J. R. Wood, and J. M. Wilmshurst. (2014). “A High-Precision Chronology for the Rapid Extinction of the New Zealand Moa (Aves, Dinornithiformes).” Quaternary Science Reviews 105: pp.126-35. [Abstract only]

Rawlence, N. J., J. R. Wood, K. N. Armstrong, and A. Cooper. (2009). “DNA Content and Distribution in Ancient Feathers and Potential to Reconstruct the Plumage of Extinct Avian Taxa.” Proceedings of the Royal Society of London: Series B. [Full article]

Scofield, R. P. & Ashwell, W. S. (2009). ‘Rapid Somatic Expansion Causes the brain to lag behind: the case of the brain and behaviou of New Zealand’s Haast’s Eagle (Harpagornis moorei).’ Journal of Vertebrate Paleontology. 29 (3). Pp.637-649.

Tennyson, A.; Martinson, P. (2006). ‘Extinct Birds of New Zealand’. Wellington, New Zealand: Te Papa Press. [Book]

Wood, J. R., N. J. Rawlence, G. M. Rogers, J. J. Austin, T. H. Worthy, and A. Cooper. (2008). “Coprolite Deposits Reveal the Diet and Ecology of the Extinct New Zealand Megaherbivore Moa (Aves, Dinornithiformes).” Quaternary Science Reviews. [Abstract only]

 

 

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Getting inside the bones

The European bison,or Wisent, (Bison bonasus) is Europe’s largest land mammal and the last surviving large grazer from a time of real giants. However, during most of the history of the species, it coexisted with other large bovines. One more familiar species was the Aurochs (Bos primigenius), the ancestor of modern domestic cattle, that went extinct in the 17th century. In Southern Scandinavia the two species coexisted for a brief period of time.

Both the Aurochs and the European bison colonized the area via a land bridge connecting southern Sweden, the Danish Isles and mainland Europe about 11,000 years ago. Remarkably, the European bison seem to have disappeared 9,600 years ago, possibly because the forests grew denser and they became isolated from the continental bison population when the land bridge was cut off due to rising sea levels. The aurochsen seem to have prevailed longer, disappearing from southern Sweden and Denmark about 7000 years ago and 3000 years ago, respectively.

The extent of the ice sheet at the Last Glacial Maximum

The extent of the ice sheet at the Last Glacial Maximum, around 20,000 years ago. Huge ice sheets covered much of northern Europe. With water trapped in the ice, sea levels were lower, and more land was connected. (Image Public Domain)

Remains of aurochsen are relatively abundant in bogs and at prehistoric human settlement sites, but only about 20 confirmed finds of European bison have been made in southern Scandinavia. This skewed ratio of finds between the two species has been proposed to reflect differences in choice of habitat due to competition or human disturbance as well as an actual difference in population sizes.

Photo taken in Réserve biologique des Monts d'Azur, Haut-Thorenc, France (Valène Aure)

The beautiful European Bison (Bison bonasus) in Réserve biologique des Monts d’Azur, Haut-Thorenc, France (Photo Valène Aure)

Although the animals looked quite different, the complete skulls are the only individual bone elements that can be positively identified as either aurochs or European bison. This means that the bones in archaeozoological assemblages, which usually are highly fragmented due to their exploitation by man as resources for food and raw materials, pose a particular challenge for species identification. As a consequence of this, one can suspect that some remains of European bison might have been misinterpreted as aurochs in previous analyses. This is common in museum collections across Europe: many specimens lay in drawers labelled as Bovine, because the post-cranial bones of the two species are so similar.

An almost complete skeleton of a European bison found at the end of the 18th century in southern Sweden. Photo by Lucas Gölén

An almost complete skeleton of a European bison found at the end of the 18th century in southern Sweden. (Photo by Lucas Gölén)

In a pilot study, researchers from Lund University, Sweden, and the Universities of York and Manchester (UK), plan to analyse bone powder from the skulls of one prehistoric European bison and one aurochs. The samples will be analysed for collagen-peptide sequencing using Zooarchaeology by Mass Spectrometry (ZooMS), a method previously used to successfully discern bone fragments from sheep (Ovis aries) and goats (Capra hircus) in archaeological assemblages. The bones of these two species are fairly similar in size and shape, and it has often proven very difficult to identify the individual species.

The purpose of the study is to investigate whether ZooMS is a feasible method for species identification of European bison and aurochs in various prehistoric bone assemblages. It is hoped that the species-specific peptide identified through the reference samples can then be used to distinguish fragments of uncertain taxonomic status. So many bone assemblages from sites contemporary with the known presence of bison in Scandinavia have previously identified as bovine and we’re aware it will need to be totally re-examined. It is hoped that the results will help to increase the number of European bison finds, increase our understanding of the species’ local history and its importance as a food source to prehistoric humans.

Written by Erika Rosengren (@RosengrenErika)

Edited by Rena Maguire (@JustRena)

For a description of the ZooMS method see: https://youtu.be/xBAXaLvGe5I

Contact: Erika Rosengren, Osteological Collections Curator. Lund University Historical Museum. Erika.Rosengren@luhm.lu.se

Further reading:
Benecke, N., (2005). ‘The Holocene distribution of European bison – the archaeozoological record’. Munibe (Anthropologia-Arkeologia) 57. pp. 421-428.

Buckley, M., Whitcher Kansa, A., Howard, S., Campbell, S., Thomas-Oates, J. & Collins, M. (2010). ‘Distinguishing between archaeological sheep and goat bones using a single collagen peptide’. Journal of Archaeological Science. 37. pp. 13–20.(http://www.sciencedirect.com/science/article/pii/S0305440309002854)

Ekström, J. (1993). ‘The late Quaternary history of the urus (Bos primigenius Bojanus 1827) in Sweden’. Lundqua Thesis 29.

Rosengren, E. (2014). ‘Sven Nilsson and the postglacial fauna of Scania’. Lund University Historical Museum. Lund.

Posted in Aurochs, Bison | 1 Comment