5 archaeological sites where ancient dietary evidence comes from fossil faeces

Last week I talked briefly about one of the more unusual ways that archaeologists study ancient diets, through looking at the contents of fossilized human faeces! Today for your reading pleasure, are 5 examples where fossil faeces (aka coprolite analysis) have given us insights into prehistoric diets around the world.

Desert Flowers and Grasshoppers: Pecos River, Rio Grande canyon Texas, dated 2800 - 1500 BP (AD 500).

The southwest USA has seen a huge amount of coprolite analysis. The dry environment and the fact that peoples occupied caves and rockshelters has meant that fossil faeces have preservation really well. One study found that human coprolites contained large amounts of zoophilous pollen - that is, pollen from plants which are pollinated by animals. This is interesting as pollen that is transported by animals doesn't get very far, and also the plants only produce small quantities of it. It is usually pollen that is transported by wind that we see more of, as it gets blown all over the place and it is produced in huge volumes. If you suffer from hayfever, it is very likely that it is wind transported pollen! So, human coprolites containing large quantities of animal transported pollen means that people were ingesting the flowers of these plants. The most common plant pollen was yucca, agave, sotol and anther, along with prickly pear cactus fruits, wild onion bulbs, goosefoot seeds and...grasshopper!

Mostly Maize, Some Small Mammals: Anasazi diet, Antelope House Arizona,  1500 - 500 BP (AD 500 - 1500).

This site is also located in a cave at the bottom of a canyon. Coprolites were examined for pollen, and also contained large amount of 'visible' particles. Pollen types included cattail and horsetail. Cattail pollen is highly nutritious, and still eaten today - you can forage for it yourself, or buy it online either as raw pollen or prepared into a protein rich flour. Maize, or corn, was found in 74% of the samples, either as whole kernels or milled. Even more interesting was the fact that the whole kernels and milled maize were never found together, which suggests that these made up two different types of 'cuisine' that were eaten on different occasions, or at different times of the year (milled maize could be stored, for example, and so could be eaten out of season). Other types of seeds found included amaranth, cactus, pine nuts, squash and physalis (you may have seen these in the supermarket - the weird little orange fruits with a papery case). Coprolites with bone fragments were found together with the maize kernels, maybe a maize and small mammal stew! These coprolites were also analysed for protein residues, which found a small number of samples tested positive for animal protein, including pronghorn, rabbit, deer, guinea pig/squirrel, cat and dog.

Lots of Rabbits: Dust Devil Cave, Utah, 8800 BC - 6800 BP

Another site where prickly pear was incredibly popular, along with chenopod seeds, other desert succulents, pinyon pine nuts, sunflower seeds, fragments of wild onion bulbs. A huge amount of rabbit bones were also found at this site, along with smaller quantities of rodents and unidentified small birds, and it is thought that these people focused their hunting efforts almost exclusively on the cottontail rabbit.

Bone Marrow: Catalhoyuk, a Neolithic 'town' in Turkey, 9400  - 8200 BP

Of course I had to mention Catalhoyuk, as it's the site I have worked on for over a decade, working on fossil faeces and rubbish heaps! It is one of the earliest large settlements in the world. Compared to the other sites above, we have a much wider range of dietary evidence from Catalhoyuk, because we have human skeletons, houses with food storage bins etc, so we can look at diet in lots of different ways. My own work has shown that some of the human coprolites have large angular fragments of bone in them. This is normally something that is associated with dog coprolites, as dogs chew on bone and ingest splintered fragments. Finding these splinters in human poop shows that people in the past had less qualms than many people do today about chewing on bone! It is possible that this was done deliberately to 'suck' or otherwise remove the marrow from the bones.

Lots of Meat, Also Veg: Neanderthals at El Salt, Spain, c.50,000 BP.

Rather than looking at the remains of seeds and bones inside the coprolites, these archaeologists looked at invisible chemical residues. They found that the Neanderthal diet was meat heavy, as has always been suspected, but also that plants were a significant component. So they were very much omnivorous, much like modern humans.


These are just a few examples. Basically, prehistoric diets were incredibly varied, and often based on what was available in the local environment on  a seasonal basis. Where in the world you are obviously dictates the types of plants and animals that were available to you. Some groups hardly ate any meat, others relied heavily on one type of animal. Some ate mostly wild plants, others engaged in cultivation, from small scale horticulture to more intense agriculture, or had a mix of food strategies that included both wild and 'managed' resources. Even in the permanent settlement of Catalhoyuk, people ate a mix of 'domestic' and wild resources.

desert succulents, parched Sporobolus (drop-

seed) caryopses, sunflower achenes, wild onion

bulbs and pin

˜

on pine nuts

Palaeodiet from Palaeofaeces

What?

Yes, you read that right, there is such a word as palaeofaeces. It's a word archaeologists sometimes use to refer to ancient human shit. It's pretty common knowledge that archaeologists work with human skeletons, so it's not that much weirder that they look at poop, right? Another word that is more commonly used is coprolite. Technically it means fossilised poop, and is the word for dinosaur poo that has turned to rock, cause it's like millions of years old. Ancient human poo isn't really old enough to be properly fossilized, but coprolite sounds much more polite than palaeofaeces doesn't it. Anyway, why I am posting about ancient poop? It's something I've talked about a lot over on my archaeology blog, and that's because it is probably one of the most useful things that we can examine in order to understand what people ate in the past. It can also tell us a lot about the gastro-intestinal health of ancient populations. So if we want to learn something about 'real' palaeodiets, it's a fun place to start.

What can you learn from ancient poo?

Just like a doctor can ask for a stool sample to check the health of your digestive tract, archaeologists can look as these little packages to get an idea of how healthy people were in the past, and what they were eating. Although a lot of the nutrients that you eat are absorbed by the body in the process of digestion, it's not a completely efficient process, and bits of the food and nutrients make their way through the body until they emerge at the other end, in an amorphous brown lump that we are all familiar with. This can include stuff you can see like fragments of bone, parasite eggs, bits of partially digested seeds and plant fibres, and also 'invisible' stuff, like chemical residues of fat and protein. We use pretty much the same tests that a doctor would to determine how much of this stuff is present, and where it came from. Unlike many of the other methods that archaeologists use to study ancient diets, looking at the stuff bundled up in a coprolite is a direct indicator of what someone was eating, over a very short period, probably a few days, along with an indication of their health. If the coprolite is well preserved, you can even slice it up into little bits to look at how the diet varied between each individual meal!

It's a bit like a detective game - not everything makes it's way through the digestive tract. Some stuff survives better than others (corn cobs anyone). So we have to be careful when we interpret the results. Ideally we look at lots of samples to get an idea of variations and whatnot. So finding ancient toilets is way more exciting than finding the next Stonehenge or some boring old precious metal object. If you're interested in palaeodiets anyway.

Next time...what sort of stuff do we know about palaeodiets that we learned from looking at palaeofaeces?

The famous Lloyds Bank turd - Viking coprolite