Eigg Dino Paper: non-technical version

I’ve had a few requests for a non-technical summary of the paper describing the recent discovery from the Isle of Eigg. Our paper, titled First dinosaur from the Isle of Eigg (Valtos Sandstone Foration, Middle Jurassic) Scotland, was published in the scientific journal Earth and Environmental Science Transactions of the Royal Society of Edinburgh in August 2020. There are 13 co-authors, each bringing their own specialism to the mix, with myself as lead author. 

But scientific papers are often a bit opaque for non-specialists. So below I've written a walkthrough of the science, written for the general public. In it, I tease out the details of our discovery and research for everyone to enjoy. If you have any Qs, please ask!

Introduction

The Middle Jurassic (174-164 million years ago) is a special time in the evolution of life on Earth. Many groups appeared at this time or shortly before, and they split into lots of new families, and exploited new ways of life. This evolutionary pattern is also true for dinosaurs. However, scientists struggle to understand how and why this happened because fossils from the Middle Jurassic are so rare. Almost five times as many fossils are known from the Late Jurassic as the Middle! As a result, every Middle Jurassic fossil is a vital clue to life at this time, and scientifically significant.

Although dinosaurs have been found in Scotland already, all of them have come from the Isle of Skye. This is because there are fossil-rich Jurassic rocks on the island dating to around 166 million years ago. As well as dinosaur limb bones, teeth, and footprints, scientists have found fossil crocodiles, turtles, pterosaurs, mammals and marine reptiles, as well as invertebrate fossils like ammonites and belemnites.

The Isle of Eigg, which lies south of Skye in the Inner Hebrides (west coast of Scotland), is also known for its Jurassic fossils. However, these are all from marine animals and mainly comprise reptiles (like plesiosaurs), fish, and sea-living invertebrates. Fossils have been found on Eigg since the early 19^th century, but in 200 years of searching no-one had ever found terrestrial animal fossils.

Our paper describes the first dinosaur bone found on Eigg, which I discovered during National Geographic funded fieldwork by the University of Edinburgh in 2017. Our small team was given permission to work on the Island by the Isle of Eigg Heritage Trust. Eigg is owned by the residents, so we had to seek their permission to work there. We found the bone on the shore where there are a series of rocks called the Great Estuarine Group. This is the same group that yields fossils on Skye. It includes many different layers formed under different conditions: some when the Inner Hebrides was a shallow sea, and others from lagoons and deltas when the land was just above sea-level. The Eigg dinosaur was in a layer called the Valtos Sandstone Formation, which was formed on an ancient Middle Jurassic shore where rivers met the sea, perhaps in a brackish (mixed salt and fresh water) lagoon.

The stratigraphy of the Great Estuarine Group, and location of the Isle of Eigg.

The Fossil

The dinosaur bone is now part of the collections at National Museums Scotland (specimen number NMS G.2020.10.1). It was removed from the shoreline using rock saws, and the bone carefully extracted from the remaining rock by expert preparator, Nigel Larkin. The Eigg bone is half a metre long, and each end is missing, which makes it hard to identify what it is. There are tooth marks on the surface, which tells us it was scavenged after death. Nigel used a kind of glue to reinforce the bone and prevent it from breaking further. There was a section of the bone missing in the middle, so Nigel used the indent in the rock as a cast, reconstructing this missing part. 

The Eigg bone, NMS G.2020.10.1. A) the bone within the rock, partly excavated, and B-C) the bone reconstructed and removed from the rock.

Matthew Humpage photographed the fossil so that we could use the pictures for the paper, then he made a photogrammetry model of the bone, which is online and free to access on a site called Sketchfab. The fossil was also studied by thin-section, allowing us to look at the internal structure. This was done by Gregory Funston, who cut a thin slice through the bone in cross-section. He ground and polished this slice down to make it thin enough to pass light through, then examined it with a microscope. We used the information about the bone structure, along with comparisons with dinosaur bones from across the UK and rest of the world, to work out what kind of animal it belonged to.

Bite marks in the Eigg Dino Bone.

Identity of the Eigg Dinosaur

Our team had to work together to figure out what animal the Eigg bone belonged to, and which bone it could be. Because there have been many marine reptile fossils found on Eigg, marine reptile expert Davide Foffa compared it to these extinct ocean-going creatures. Swimming animals have special adaptations in their bones for their way of life, including having very short, wide limb bones, and thickened internal bone structure. Not only was the Eigg bone not the same shape as a marine reptile bone - it was too long and slender – it was not thickened like a marine animal bone. This meant we could be sure it wasn’t a marine reptile, and must be some kind of dinosaur.

Next we compared the bone to the three main groups of dinosaurs: theropods, sauropods, and ornithiscians. Co-authors Stephen Brusatte, Femke Holwerda, and Susannah Maidment are all dinosaur experts, and so were able to work systematically through all the possible identifications, narrowing it down. Because it was badly damaged, the Eigg bone didn’t have any diagnostic features (features that help identify the species) to guide us. Instead, we had to use detective work to narrow down the possibilities. It didn’t match the shape of theropod bones, but bore some resemblance to sauropod fibulae – the smaller of the two lower hind leg bones. It was also similar to a sauropod femur, but it would have to have been a particularly small, slender sauropod. Overall, the Eigg bone bore the closest resemblance to an ornithiscian fibulae, having the same length and width, and similar shape in cross-section. Ornithiscians include Stegosaurus and other armoured dinosaurs, which are already known from the Jurassic of the Northern Hemisphere, including sites in England.

Top) the skeleton of a Stegosaurus (from Natural History Museum London) showing the lower hind leg bones. Bottom) the cross-section of the Eigg Dino Bone, used to study the microscopic structure.

Greg’s cross section of the bone gave us the final clues we needed to identify it. He could tell from the fine detail of the bone structure that it was most likely an ornithischian – specifically a thyreophoran, which includes animals like Stegosaurus. The holes left behind by blood vessels told us that it had a relatively slow growth rate – unlike sauropods which grow very quickly to large sizes. There was a lot of secondary remodelling in the bone, which is when the bone alters as the animal grows. Very similar patterns are seen in stegosaurs like Hesperosaurus, Kentrosaurus and Stegosaurus.

Another thing Greg could see in the bone structure were lines that accumulate as the animal matures. These are known as LAGs (lines of arrested growth), and are found not only in bones, but also in teeth. The Eigg bone had a single LAG, which tells us it was older than one year in age, perhaps just a few years older – a youngster by dino standards. There was no sign that growth had stopped, so it was probably still actively growing before it died.

Conclusions

Putting all of this information together, we can tell that this is a limb bone from a stegosaur-like dinosaur. It is most likely a fibula, or hind lower leg bone. The animal was only young when it died, and was washed into a lagoon by the sea, or perhaps just off-shore, where it was chewed-on by marine reptiles.

Although dinosaur fossils in Scotland are few, and much less complete than those found in more famous Jurassic exposures in England, they are equally important. They add data to our Spartan picture of this time period. The bone from Eigg is also significant for Scotland as the first dinosaur fossil outside of Skye, and the first belonging to a stegosaur-like, thyreophoran dinosaur. It backs up the suggestion made recently by Paige dePolo and her co-authors that fossil trackways found on Skye belonged to thyreophorans.

It has taken 200 years of searching to find this dinosaur fossil on Eigg, but hopefully it won’t take as long to find the next one! Our team is grateful to our sponsors and the people of Eigg for their support – hopefully there are many more fossil discoveries to be made in the Inner Hebrides to enrich our understanding of life in the time of dinosaurs.

On Finding a Dinosaur

They tell me I’m good at finding things. Word searches, jigsaw puzzles - they are unintentional brain-training to isolate patterns in chaos. When looking for fossils it takes a few attempts to recognise what you’re seeking. Then they say you ‘get your eye in’, or that you ‘have the eye’ for it. I tell them, I have two.

I found my first dinosaur on a glorious sunny day in the Inner Hebrides. I leapt from boulder to boulder across the foreshore of the Isle of Eigg, sprinting like a mountain goat back to my teammates. With each jump I looked down to place my feet securely on dry Jurassic sandstone, which Velcro-gripped the soles of my tattered hiking boots. The stench of sulphur was making me dizzy – a nearby pool choked in marine algae was festering in the hot May sunshine. To avoid it, I moved up shore. As I flew down from a high platform into a small shingle inlet, I saw a silhouette. Long, with a bulbous end. Pattern recognition. 

Shoreline on Isle of Eigg, with Isle of Rum in the distance.

Momentum carried me several steps further along the clattering shingle before I fully registered what I’d seen. I skidded and turned back. The shape was nestled in a boulder tucked below the sandstone outcrops. I crouched down and reached out, running my fingertips across the rough surface. The electric-thrill formed a Bifröst to the ancient past.

Most fossils are not worth collecting, and that’s where scientific knowledge comes in. It was my fourth palaeontological expedition with teams working in my home-country of Scotland. That day in 2017 I recognised the black splodge on the rocks of the foreshore as the remains of a limb bone. It looked like burnt charcoal, the surface cracked as though oven-baked. Where the bone was damaged I saw the tell-tale honeycomb of a structure once-living; the strut of biological architecture, nature’s engineering exposed. A portion of the long mid-shaft was gone, leaving a ghostly indent in the rock. A million frozen grains of sand encased one end of the bone, reluctant to let it go. This stone had carried it for 166 million years like a time-capsule. It was a dinosaur limb bone. I took photographs, then turned and sped South again. 

The Eigg dinosaur bone, or StEiggosaurus, moments after I found it.

When I found my team mates I told them I’d found something. What is it? they asked. I knew how disappointing it was when your ‘fossil’ find turned out to be a bit of driftwood, or a splatter of solidified tar, so I replied that I wasn’t sure, but maybe a limb bone... What kind of limb bone? They pressed. I sheepishly mentioned some possibilities, non-commitally mumbling dinosaur.

I led them back along the shore. When they caught up and saw it, their faces exploded like grin-grenades. They knelt and examined it, agreeing it was indeed a dinosaur limb bone. The first dinosaur I’d found, and the first dinosaur ever found on the Isle of Eigg.

We took photographs and notes, planning how it could be collected. In the following weeks a team arrived by boat to slice through the shore and cut out its dinosaur heart. This bone - which had drifted offshore in the Jurassic sea and come to rest in a sandy bed for a geological nap - now drifted once again, southwards to the lab of our colleague, Nigel Larkin. He carefully removed the surrounding sandstone, exposing the limb bone for us to study.

My artwork showing the kind of dinosaur the Eigg bone belonged to. It may have died crossed a river or delta, and been washed out to sea.

It was scarred by scavengers, and the ceaseless surf of Eigg had made off more than half the evidence, one granule at a time. To figure out to which animal it belonged, I worked with palaeontologists who specialise in different groups of extinct reptile: Femke Holwerda (sauropod-lover), Susannah Maidment (queen of stegosaurs), Davide Foffa (marine reptile chaser), Stephen Brusatte (theropod enthuser). With so little of the bone left to study, we turned to the tell-tale biological structure for further clues. Gregory Funston examined the microscopic structure of the bone, a codex for an animal’s growth. The evidence combined to tell us that this was the leg bone of a stegosaurian dinosaur, a plate-backed herbivore of the Jurassic. An early resident of Eigg, now at rest in the National Museum of Scotland in Edinburgh.

By the time the whole team had assembled to look at the discovery on the shoreline that Summer’s day, I was already elsewhere. I’m restless as a wave, prefering movement. Hopefully life will always find me leaping along fermenting shorelines and shuffling below cliffs. I revel in zenful hours squinting at glinting surfaces, with salt spray scratching my lips and flaying my fingertips, sifting through ancient sands for fragments of Jurassic Scotland. 

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Panciroli, E., Funston, G. F., Holwerda, F., Maidment, S. C. R., Foffa, D., Larkin, N., Challands, T., dePolo, P., Goldberg, D., Humpage, M., Ross, D., Wilkinson, M., Brusatte, S. L. 2020. First dinosaur from the Isle of Eigg (Valtos Sandstone Formation, Middle Jurassic), Scotland. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 1-16.

Scottish Fossil Workshops Programme

This summer I delivered a programme of Fossil Workshops to schools across the Highlands of Scotland, funded by the Palaeontological Association. Covering 1,500 miles and speaking to over 300 pupils, I shared stories of Scotland’s amazing fossils, taught pupils about the science of palaeontology, and encouraged them to protect their precious natural heritage.

I grew up in the rural Scottish Highlands, in a geographically remote location famed for its geology. Our primary school—which at its zenith had about nineteen pupils in total—rarely received visits from outreach programmes, and I don’t remember ever meeting a scientist. Despite knowing the landscape intimately, our community was cut-off from the research and teaching being carried out in our hills.

To address the disconnect between rural communities and science, I put together the Scottish Fossil Workshops programme, and secured funding from the Palaeontological Association’s Engagement Grant scheme. The aim was to reach schools in parts of Scotland that don’t regularly receive outreach, either because their location is distant from towns and cities, or due to low pupil numbers. It’s never difficult to get children excited about fossils, what’s more challenging is widening their interest beyond the toothy trappings of Tyrannosaurus. Scotland has an incredible fossil heritage, brought into the public spotlight in recent years by media attention on the Jurassic material—particular dinosaur footprints—found on the Isle of Skye, where my team and I carry out our research. But there are so many more tales told by Scottish fossils that extend well beyond terrible lizards: preserved bodies in rocks that whisper to us about our changing environment and the evolution of life on earth

To create the workshops I enlisted the help of Matt Humpage, a graphic designer and digital artist I’ve recently worked with on the geological-themed anthology, Conversations in Stone (with co-editor Larissa Reid). Matt volunteered to design a bespoke colour scheme and logo for the workshops, creating banners and headers for use in promotional material. Together we compiled an activity booklet for participating schools that included geological colouring-in and drawing activities, a Scottish fossil wordsearch, puppet making, and much more. I received many generous donations of books, leaflets and posters about fossils and geology for inclusion in the activity pack. The PalAss funding was used to 3D print a selection of Scottish fossils, and these augmented real fossils for the children to handle, on loan from the Natural Sciences department at National Museums Scotland (NMS). 

Each fossil was a gateway to talk about extinct life and evolution.

Pupils were encouraged to ask lots of questions!

Matt and I set off at the start of May for our workshop tour. It’s a logistical challenge reaching widely dispersed rural schools, so I set the achievable goal of delivering two workshops per day over two weeks. Workshops were two hours in length, and comprised three components: an interactive PowerPoint presentation, a fossil-handling session, and a fossil-themed game. This structure helped balance listening activities with practical components, keeping children aged between five and twelve engaged with the content.

‘Great balance between focused, practical, and active tasks.’ - Teacher

The pupils were overjoyed to have a palaeontologist visit, and the fossil-handling session was a massive hit. I had selected the fossils to complement the presentation, which was split into: 1) What are Fossils?; 2) Fossils of Scotland; and 3) Being a Palaeontologist. I tied content into the Scottish curriculum for Excellence (CfE), particularly evolution, scientific enquiry, skills building, ecosystems, climate change, and digital technologies. This meant the content could be integrated into the wider teaching framework of the school. Each school was given a 10x enlarged 3D print of our recently published complete Borealestes jaw —Scotland’s first-discovered Mesozoic mammal—along with a fact sheet about it, and the process of digital printing.

Scotland’s fossils provide a vivid storyline about environmental change and the evolution of vertebrate life. I chose key examples to illustrate this: the Devonian fossil fish of Caithness and Orkney; the first animals on land from the Carboniferous Borders; the strange desert-dwelling Permo-Triassic synapsids of Elgin; and finally, the rich lagoon fauna of Jurassic Skye. For each one I linked the fossils both to Scotland’s landscape and to us, telling the tale of the emergence of the mammal lineage. 

Fossils included plants and trace fossils as well as bones and 3D prints.

Schools were given a free 3D print of Borealestes, a Jurassic mammal first found on the Isle of Skye.

To emphasise the diversity of people and subjects in palaeontology, my presentation included a range of scientists from different ethnic and socio-economic backgrounds. We talked about the various research themes palaeontologists follow, and the many skills scientists employ—including less obvious ones such as art, teamwork, and communication. Teachers commented that this emphasis on a wide range of skills was inclusive and helpful for them to link taught subjects to their practical applications.

Arguably the most important goal of the workshops was to encourage the pupils to be responsible citizen scientists. Most of them had already collected fossils from local sites, and some brought examples to show me, such as ammonites and crinoids. One way to address the problems that can arise from unregulated collecting is to educate young people to protect their local natural heritage. To achieve this I incorporated the Scottish Fossil Code (created by Scottish Natural Heritage, SNH) into the talk, simplifying the message into four bullet points: Ask an Adult (don’t collect without checking it’s okay with landowners); Be Responsible (look after yourself and look after nature); Be a Good Scientist (take notes about what you find); and Tell and Expert (if you find something, show it to someone!) The children were extremely receptive to the idea that by behaving responsibly they were being like real scientists, as well as looking after their environment.

Our parting gift to the teachers was to over-excite their pupils with the role-playing Fossilisation Game. Adapted from a simpler version I found online, this game taught them about taphonomy and fossil bias. Pupils were allocated animals from Jurassic Skye, and encouraged to role-play as their animal (you can imagine the chaos). After a few minutes, we yelled at them to all ‘drop dead!’ As they lay giggling in dramatic death poses on the floor, I circulated a bag of cards to draw from randomly, and these told them if they became a fossil or not, and why. We then looked at how representative the remaining fossils were of the original animal assemblage, and the ‘best’ ways to become a fossil. 

I adapted a fossilisation game I found online to make it Jurassic Skye themed.

Anyone who does regular outreach work in schools will know how intense and exhausting it is. Between visits we spent hours on the road, often only able to pick up basic food from petrol stations or supermarkets and eating it in the car on the way to our next location. But the results, and the excitement of the pupils, were more than enough reward for the effort.

‘Yes! It’s fab for kids here to experience visits like this! We’re so far away from cities!’ - Teacher

‘Thank you! The kids all LOVED the workshops – please come again soon!’ - Teacher 

In the following months pupils entered our Scottish Fossil Art Competition. We received 127 entries, and there were four winners and 18 highly commended entries, chosen in consultation with the Natural Sciences department at NMS. The prizes included books, stickers, and postcards of extinct animals, and a ‘Palaeontologist’s Starter Kit’, with hand lens, notebook, and identification guides. As well as this, one overall winner received a rock collection for their school to learn from, containing the main rock types found in Scotland (generously donated by Angus Miller of the Scottish Geodiversity Forum).

The winners of the Scottish Fossil Art Competition.

Winners received this pack of prizes.

The overall winner also won a Scottish rock collection for the whole school to enjoy.

It was an amazing experience, made possible by PalAss funding (grant number PA-OE201801). I couldn’t have done it without the generous support and donations from NMS, SNH (especially Colin MacFadyen), the Scottish Geodiversity Forum, the STEM team at the University of the Highlands and Islands (esp. Mairi Stewart),  Dunedin Academic Press (esp. Anthony Kinahan), and the British Geological Survey in Edinburgh. Thanks to Roger Benson and Steve Brusatte for providing additional Skye fossils to print. I’m so grateful to everyone who supported me, and of course to Matt Humpage for helping design the content and deliver the workshops.

With an increased interest in Scotland’s fossils, it’s important to share the science of palaeontology with as many people as possible. It would be amazing if the workshops could continue, ideally expanding to reach the rest of Scotland. Hopefully more of us will take our research back into communities—who knows, maybe it will inspire the next generation of citizen scientists to pursue careers in research and conservation?