Showing posts with label evolutionary biology. Show all posts
Showing posts with label evolutionary biology. Show all posts

Monday, 16 September 2019

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 schoolwhich at its zenith had about nineteen pupils in totalrarely 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 materialparticular dinosaur footprintsfound 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 mammalalong 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 employincluding 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 communitieswho knows, maybe it will inspire the next generation of citizen scientists to pursue careers in research and conservation?

 

Friday, 19 July 2019

Say hyoid to the latest Jurassic mammaliaform from China


China continues to amaze us with its fossil treasures. The latest is a 165 million year old Jurassic mammal, belonging to my favourite group, the docodontans. Docodontans are one of the earliest branches of mammaliaforms, the wider group that includes Mammalia. They are our cousins, and in the last twenty years they’ve transformed our understanding of mammal ecological diversity in deep time, because they’ve basically done it all before. This group includes the first mammal specialist diggers, swimmers and tree-climbers, occupying these niches long before modern mammals were on the scene. Their teeth were complex, with a triangular arrangement of cusps and troughs that later convergently evolved in modern mammals. In other words, docodontans are the trend-setters of the mammal world.

The docodontans were incredibly ecologically diverse in the Jurassic. They include climbers like Agilodocodon, swimmers like Castorocauda, and diggers like Docofossor. Amazing palaeoart by April I Neander, University of Chicago.

This new genus and species is called Microdocodon gracilis. The name says it all: this creature was tiny and slender. With an estimated body mass of just 5-9 grams, it’s on a par with the modern shrews, Sorex. Unlike them, it has an elongate face and limbs and a long tail, suggesting it may have been a competent tree-climber as well as ground-scurryer (this combination is also known as being scansorial). What’s really stunning about this wee beastie is something common to many of the spectacular fossils of China: it is exquisitely preserved with almost every bone in articulation. This includes bones that are usually too small and fragile to survive fossilisation, such as the hyoid.




So what is a hyoid? You may know it from crime dramas like CSI; it’s the bone in the throat that is often damaged when a murder victim has been strangled. If you locate your larynx (the ‘Adam’s apple’) in your own throat, then feel upward to the area where your chin meets your neck, you can feel it in there. It’s not in contact with other bones, but floats there, anchored in place with muscles and ligaments. The hyoid is where your tongue and the other muscles in the floor of your mouth attach, and it is intrinsic to swallowing and moving the tongue.

Position of the hyoid in humans (red). From Wikipedia

When you’re looking at mammal skeletons in museums, the hyoid bone is often conspicuous by its absence – it’s a tricky wee blighter, and I suppose that it is often lost or too fiddly to make it to the skeletal mount. However, it is an important and unique part of the skeleton, inherited by vertebrates from their common ancestor over 375 million years ago. The hyoid originates from the same embryonic structure that becomes the second gill arch of fishes; those loops of bone that support the fish breathing apparatus. In mammals it has taken on a special significance, because it’s thanks to the hyoid that mammals literally suck.

Mammals use the control provided by the hyoid to suckle and feed on liquefied food, often processed by their complex teeth, but also including milk from their mothers. Mammals are not the only animals that suck of course. There are other vertebrates that use the hyoid to create a vacuum for feeding. The turtle Chelus fimbriata, or mata mata, for example, has a large hyoid and a pair of flappy cheeks, which it opens suddenly to draw-in passing fish by suction. As well as suction, this bone allows for special movement of the tongue: lizards and snakes carry out their characteristic tongue-flicking thanks to their hyoid bone and attachments.

Embryology reveals the origin of the structures of the face. Source

Due to its role in swallowing, the hyoid can provide clues about the kind of food being eaten by the earliest mammals. Microdocodon has a saddle-shaped and complex hyoid that is the clear predecessor of later mammalian hyoid bones. This tells us that this animal had a muscular throat with good control of the ability to swallow. The authors suggest that the very modern structure of Microdocodon’s hyoid is linked to the ability of early mammals with complex teeth to chew their food until it was well liquefied. This required a sophisticated and controlled ability to swallow the food. We also infer from the tooth replacement patterns of the first mammals that they likely fed milk to their young (they had 'milk teeth' followed by adult teeth), which would also require controlled ability to suck and swallow. Therefore it is likely that this complex hyoid structure appeared in the common ancestor of docodontans and the rest of the mammals, and not in earlier mammal relatives, because the latter didn’t have such complex food processing abilities.

More amazing artwork by April I Neander

Unlike modern mammals, docodontans still had their middle ear bones attached to their jaws. In modern mammals these bones have become the malleus and incus, and help provide our extra-sensitive hearing capabilities. This new Chinese fossil gives us previously unknown information about how the hyoid was positioned in ancient mammals – and therefore the larger patterns of its evolution and function. The only other Jurassic hyoid known belongs to Vilevolodon, a haramiyidan mammal. Because there is an ongoing disagreement about whether haramiyidans are an early branch of mammaliaforms, or a much more derived group belonging to crown Mammalia (that’s a blog for another time), the evidence from Vilevolodon comes with baggage. Microdocodon however, is a safe phylogenetic bet, and so uncontroversially clarifies the structure of this feature in the earliest mammals.

Such a great fossil, and continued proof that docodontans are among the most exciting group of mammals from the Mesozoic. 




References

Lemell, P, Beisser, C, Gumpenberger, M, Snelderwaard, P, Gemel, R, Weisgram, J. 2010. The feeding apparatus of Chelus fimbriatus (Pleurodira; Chelidae) – adaptation perfected? Amphibia-Reptilia. 31: 97-107.

Luo, Z-X,  Meng, Q-J, Grossnickle, DM, Liu, D, Neander, AI, Zhang, YG, Ji, Q. 2017. New evidence fo rmammaliaform ear evolution and feeding adaptation in a Jurassic ecosystem. Nature 548, 326–329.

Zhou, C-F, Bhullar, B-AS, Neander, AI, Martin, T, Luo, Z-X. 2019. New Jurassic mammaliaform sheds light on earlyevolution of mammal-like hyoid bones. Science, 365:276-279.