The Geological Record is Full of Cr*p

Written by Nigel Larkin, who is a GCG Committee Member, and palaeontological preparator, conservator and curator (Natural History Conservation)

Like many people who are members of the Geological Curators’ Group, my passion for geology and palaeontology isn’t just a 9 to 5 thing. I wouldn’t say it is an all-consuming 24/7 obsession either but as well as being the mainstay of my three-decade-long career in museums it has influenced my choice of holidays, the books I read, the social media I follow and the woman I was lucky enough to marry: she likes fossils and fossiling? Tick! Anyway, my point is that when I am not cleaning, preparing, conserving, mounting, moulding and casting, CT-scanning, curating, or researching fossils and geological specimens to pay the bills (whilst admittedly having a certain level of fun), I do have a few related hobbies. For instance, like most people in this line of work when I can I like to get out and about and visit locations where interesting rocks and fossils might be found. This tends to be when I am en route to one museum or another for work purposes so I often hit the appropriate beach/cliff/quarry nearby as dawn breaks to get a couple of hours fossiling in before my meeting (which accounts, but only in part, for my dishevelled nature when you see me).

My specialist area when it comes to finding specimens is trace fossils. I take great delight in these.  I have found countless lovely examples of ripples frozen in time, tetrapod trackways (even rhynchosaur trackways splashing through muddy ripples) slabs of fossilised raindrop impressions, trackways and footprint casts, dinosaur gastroliths and coprolites (fossilised dung). Hundreds and hundreds of coprolites. I seem to be a coprolite magnet. Now, I know full well that most things that people think might be coprolites simply aren’t: these include nodules (particularly nodules of pyrite), poorly preserved ammonites, odd-looking rocks and ‘water escape features’ to name but a few. And we all know that those ‘Coprolite mines’ in East Anglia in the 19th Century were not in fact excavating layers of ‘dinosaur dung’ but mostly completely unrelated phosphatic nodules (Ford and O’Connor, 2002). But after many years of research in this area (you have to have a hobby!) I do know my sh*t. I have a collection of ‘pseudo coprolites’ and I have a collection of real coprolites. And OK, I do also have a collection of modern dried animal droppings as well – oh and a freezer full of hundreds of recent crocodile, alligator and caiman droppings for palaeontological research purposes. Heaven help us if we ever have a power cut. These crocodilian scats have been collected for me by the kind staff at ‘Crocodiles of the World’ near Oxford. Do go and see them, it is a great day out particularly if you are into reptiles: as well as crocodilians they have lizards, monitors, snakes, tortoises (including giant Galapagos tortoises!) and even a komodo dragon.

A brief digression: I am sometimes literally up to my elbows in recent excrement – not just because I have children and in turn they have amassed what amounts to a small zoo – but because, as I mentioned at the beginning, I am a conservator and a ton of horse manure can be very effectively used to clean and degrease really oily, smelly half decomposed whale bones. See the Carlisle Whale Project for an example.

After a few months of this treatment the whale bones do then smell of manure, of course, but that is far preferable to the stench of dead and rotting baleen whale, believe me. Don’t fear, they are effectively cleaned further with ammonia. Which leaves them stinking of ammonia instead. But this does – eventually – fade. Thankfully. So, back to the coprolites…

Where can you find coprolites easily in the UK?

Most of these locations are Sites of Special Scientific Interest, so responsible collecting is allowed but obviously no hammering etc or removal of in situ material.

Probably the most well-known site where coprolites are easily found is the Rhaetic ‘Bone Bed’ in upper Triassic deposits at Aust on the Severn estuary, just below the old River Severn crossing (the old M4, now the M48). This bone bed actually consists of more coprolites than bones so it should really be called the ‘Coprolite Bed’. This layer is located at the top of the cliff so in situ material is not accessible but you can nearly always find chunks that have fallen on to the foreshore. The coprolites are thought to be from shark and other fish, and possibly from small reptiles (Swift and Duffin, 1999). Oh, and as well as coprolites the bone bed does also contain the remains of disarticulated ichthyosaurs, plesiosaurs, other reptiles and fish if you are into that sort of thing. See: https://ukfossils.co.uk/2010/03/04/aust-cliff/

Piece of bone bed with a shark fin spine at the top, a bone protruding top right and about 20 coprolites in cross-section. Specimen 110 mm long. © Nigel Larkin.

The coast at Blue Anchor in Somerset yields slabs of very similar fossiliferous Rhaetic Bone Bed liberally sprinkled with coprolites and some bones. See: https://ukfossils.co.uk/2012/02/02/blue-anchor/

If individual coprolites (as opposed to slabs of bone/coprolite bed) are what you would like to find then I recommend you head for Bouldnor near Yarmouth on the north coast of the Isle of Wight. I have umpteen dozen coprolites from here, all found along the foreshore, but exactly what is responsible for these is a bit of a mystery. They are fairly large and whilst the (usually disarticulated) remains of reptiles such as turtles and crocodiles are quite common in these Oligocene deposits so are those of medium-sized mammals such as anthracothere (hippo-like artiodactyl ungulates). The coprolites aren’t from the turtles, judging by their shape. They could be crocodilian in nature, or anthracotherian. See: https://ukfossils.co.uk/2005/08/06/yarmouth/

Classic Bouldnor coprolite, Oligocene in age, nicely folded. Length 92 mm. © Nigel Larkin.

The north coast of Edinburgh is a good place for finding much older coprolites. Wardie Bay or just beside the Forth railway bridge at Queensferry (on the southern shore of the Firth of Forth) are both great spots for finding Carboniferous shark coprolites, made famous by William Buckland’s table of sliced and polished coprolites (see, you can polish a turd!). This is now on display in Lyme Regis Museum. See: https://ukfossils.co.uk/2007/06/01/queensferry/

A dozen coprolites found loose at Queensferry, Edinburgh. © Nigel Larkin.

Want a challenge? Where can you find coprolites less easily in the UK?

The West Runton Freshwater Bed on the coast of north Norfolk is not only the Type Site for the Cromerian interglacial but this is where the famous West Runton Mammoth was found. This is an 85% complete skeleton of a Steppe Mammoth and the best example of its species in the world. The missing 15% seems to have been devoured by spotted hyaenas that left their droppings scattered among the carcass and elsewhere in the old riverbed (Larkin et al, 2000; Stuart and Larkin, 2010). They can still occasionally be found by a diligent collector, but they are rare. See: https://ukfossils.co.uk/2004/09/18/west-runton/

Spotted hyaena (Crocuta crocuta) coprolite. One of many found with the scavenged skeleton of the West Runton Mammoth in north Norfolk. This was preserved in an upright position. Height 115 mm. © Tony Stuart.

The trace fossils that the coast near Whitby is most famous for are the dinosaur tracks and foot casts from the middle Jurassic, which are relatively easy to find. However, I have twice found coprolites there. One in situ in Saltwick Bay, and one in a nodule loose on the beach at Sandsend (on Mary Anning’s birthday last year, 21st May 2019). I only get to visit that coast about once a year though. Local collectors find coprolites infrequently but they are known. Marine in origin, they are probably from marine reptiles such as plesiosaurs and ichthyosaurs. See: https://ukfossils.co.uk/2007/03/18/saltwick-bay/

Hock Cliff, Gloucestershire. I cannot find any records of coprolites having been found at this classic lowermost Jurassic (Hettangian) locality on the banks of the River Severn just upstream from Aust. But I found a rather lovely example there a few years ago clearly containing fish remains. See: https://ukfossils.co.uk/2010/03/04/hock-cliff/

Coprolite from the lowermost Jurassic, Hock Cliff, River Severn, with visible fish remains. Length 51 mm. © Nigel Larkin.

Kimmeridge. All sorts of trace fossils have been found in the Upper Jurassic deposits at Kimmeridge by the world-renowned collector Steve Etches. Coprolites are relatively rare, but I have found a handful. Be aware though – some of these coprolites are naturally radioactive!

Coprolite in matrix from Kimmeridge, Dorset. Coprolite length 44 mm (I need to finish preparing this. I found it about 25 years ago!). © Nigel Larkin.

A few of my favourite things

When I was Curator of Geology for Norfolk Museums Service and ran earth science events for the public I used to deploy one of my favourite fossils, given to me almost 30 years ago by Steve Etches. This is a large, solid coprolite made by a turtle, in what is now the USA, during the Cretaceous.

People know that teeth and bones fossilise but they also know that these are hard to start with. Take a fresh-looking squiggly mass that is clearly a poo but rap that quite hard on a desk and it more effectively gets across the idea of something turning to stone over time. And kids love a coprolite. It engages their naturally scatological sense of humour.

Cretaceous turtle coprolite, USA, length 90 mm. © Nigel Larkin.

The only coprolite I have ever bought is a large (2.7 kg) sectioned specimen from Cretaceous deposits in Morocco, apparently from a sauropod dinosaur. I bought this because, unbeknown to the seller, it seems to have been burrowed into when it was fresh, presumably by a type of dung beetle, and so is a great example of different animals in an ecosystem living together in the landscape, one dependent on the other.

Probable sauropod dinosaur coprolite from Cretaceous deposits in Morocco. Length 168 mm. © Nigel Larkin.

The book: A Prehistory of the World in 101 Coprolites.

I am currently writing – admittedly very slowly between work contracts – a book provisionally titled ‘The Prehistory of the World in 101 Coprolites’. Yes, really. This fully referenced but hopefully easily-accessible book will be illustrated with gorgeous photos of coprolites in all their glory from all around the world (including the Antarctic – thank you BAS!). It will include examples of polished sections, thin sections, and Micro CT scans, and will present specimens from throughout the fossil record including from bony fish, sharks, turtles, marine reptiles, mammoths, hyaenas, ground sloths, insects (including some insects in amber with their frass), beetles, Neanderthals, early humans, and ancient Egyptians, right up to “The Viking Turd” (Darcens, 2011) in York. I will examine all the stories these specimens can tell us about diet, predation and other animal behaviour such as communal Permian latrines, parasite infestation and beetle larvae using their own faeces to construct a hard case in which to hide and pupate – unless they get preserved forever entombed in their own faecal case within amber (thank you Penney and Jepson, 2014!). The book will demonstrate how faunal communities evolved over time, responding to the world changing around them including extinction events. Well, that’s the plan.

So if you have a favourite coprolite story, know of some relevant interesting research, or have a particularly photogenic/exotic/strange or quirky coprolite in your collection then please do get in touch (@MrIchthyosaurus).

References:

D’arcens, L. (2011). Laughing in the face of the past: Satire and nostalgia in medieval heritage tourism. Postmedieval: A journal of medieval cultural studies, 2(2), 155-170.

Ford, T. D., & O’Connor, B. (2002). Coprolite mining in England. Geology Today, 18(5), 178-181.

Larkin, N., Alexander, J., and Lewis, M. (2000). Using experimental studies of recent faecal material to examine hyaena coprolites from the West Runton Freshwater Bed, Norfolk, England. Journal of Archaeological Science 27, 19-31.

Penney, D. and Jepson, J.E. 2014. Fossil insects. An introduction to palaeoentomology. Siri Scientific Press. Manchester.

Stuart, A. J., and Larkin, N. R. (2010). Taphonomy of the West Runton mammoth. Quaternary International, 228(1-2), 217-232.

Swift, A. and Duffin, C. J. 1999. Trace Fossils. In Fossils of the Rhaetian Penarth Group, edited by Andrew Swift and Dave Martill, Palaeontological Association.


One thought on “The Geological Record is Full of Cr*p

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s