Brains, brains, brains! (New paper out today)

Our latest paper was published yesterday in the journal Royal Society Open Science. This work was co-authored by myself with Tom Challands (University of Edinburgh) and Jason Pardo (University of Calgary), and has the title: “Mandibular musculature constrains brain–endocast disparity between sarcopterygians.”

In this work we applied a method developed in a previous paper to quantify and visualise the spatial relationship between the brain and its surrounding braincase in several animals. We investigated the living lobe-finned fishes (the coelacanth, Australian and African lungfish), as well as two salamanders (the axolotl and a newt).

Why did we do this? Firstly, brains are soft organs and so rarely fossilise and instead we are often only left with the hard, bony remains of an animal. This means that we must rely on the shape of the internal mould of the skull (an ‘endocast’) as a proxy for brain size and shape.

However, while birds and mammals typically have brains that nearly completely fill their brain cavities, those in fish, amphibians and reptiles are usually not so tightly constrained. This means that when we try to interpret the endocasts of fossils of extinct fish and early tetrapods (backboned animals with four limbs bearing fingers and toes) we don’t know with how much confidence we can infer how large certain brain regions were.

We found that the coelacanth is doing something very strange and has an absolutely tiny brain contained within a huge braincase (similar findings have recently been reported elsewhere). However, the lungfish and salamanders have brains that are filling their braincases to a higher degree than previously thought. We suggest that these patterns may potentially be related to the reinforcement in the skull from large jaw muscles, but we do need to examine some other basal tetrapods, such as frogs and caecilians, before we can be completely sure.

Left figures show overlap relationship between brain (grey) and endocast (red).
Right side images show the same information using a “heat-map” approach.
a-c, axolotl; d-f, newt; g-l, African lungfish; m-o, Australian lungfish; p-r, coelacanth.
(Silhouettes from http://phylopic.org/)

By investigating the brain-braincase spatial relationship in these living animals spanning the fish-tetrapod transition, we can use this information to better interpret fossils spanning the same critical juncture.

This approach is guided by something called the Principle of Proper Mass (Jerison 1973) which proposes that the larger a brain region, the more likely it is to be processing more information (remember that growing and maintaining large brains is energetically costly). Thus, if an animal has particularly large optic lobes compared to the olfactory region for example, we can reasonably assume that that animal relied more on its vision that its sense of smell.

It is my hope that this work will help us to pinpoint the origins of new behaviours as fish moved out of the water and began to colonise land over 385 million years ago.

YTP 2020

It was a great honour to receive my Young Tall Poppy award last night from His Excellency the Honourable Hieu Van Le AC in the Eclipse Room at the University of Adelaide.

Dr Alice Clement with her 2020 Young Tall Poppy Award.

“The Tall Poppy Campaign was created in 1998 by the Australian Institute of Policy and Science (AIPS) to recognise and celebrate Australian intellectual and scientific excellence and to encourage younger Australians to follow in the footsteps of our outstanding achievers.”

The award night was held in collaboration with Inspiring South Australia and National Science Week to celebrate both the Young Tall Poppy crop of 2020, but also the Unsung Hero Awards of South Australian science.

In particular, I wish to congratulate Graham Medlin from the South Australian Museum, citizen scientists Robert and Rosalie Lawrence for ‘Wild Orchid Watch’, and Dr Kylie Dunning (ARC Centre of Excellence for Nanoscale BioPhotonics) for their awards.

I feel very lucky to have been nominated by my mentor, Prof. John Long, and it was great to be able to celebrate in person on the night and hear about the varied research and outreach happening here in South Australia.

Dr Alice Clement with Prof. John Long at the 2020 SA Young Tall Poppy & Unsung Hero Science Award night.

Young Tall Poppy

I’m really excited to announce that I’ve been named one of the 2020 SA Young Tall Poppies by the Australian Institute of Policy and Science (AIPS).

The prestigious annual Young Tall Poppy Science Awards aim to recognise the achievements of Australia’s outstanding young scientific researchers and communicators. In particular, the ‘Tall Poppies’ are awarded to those who promote interest in science among school students and teachers, as well as an understanding and appreciation of science in the broader community.

I was one of three researchers from Flinders University recognised for our research and communication efforts, and I feel honoured to be in the company of hydrogeologist Dr Margaret Shanafield and archaeologist Dr Ian Moffat in this year’s cohort.

YTPx3
Photo credit: Tania Bawden, Flinders University

Congratulations to all other awardees, and many thanks to my supporter and nominator, Prof. John Long. There will be an official award ceremony in September held in the Reading Room of the Barr Smith Library with South Australia’s Governor, His Excellency Honourable Hieu Van Le.

Impact Seed Funding

I was fortunate enough to receive Impact Seed Funding from Flinders University in 2018. While in the grand scheme of things it was a relatively small amount of money, for an Early or Mid-Career Researcher (EMCR), awards like this can go a long way.

This funding enabled me to pursue my own line of research into palaeoneurology (fossil brains) and supported a visit to the Berlin Museum für Naturkunde (Natural History Museum) and a trip to the famous Institute of Vertebrate Paleontology & Paleoanthropology (IVPP) in Beijing, China.

Having museum visits funded in this way help me to research how brains evolved in our early fish ancestors, and enable me to try to understand the adaptations and novelties acquired in the brains of the first tetrapods (terrestrial vertebrates). Studies such as these go on to form “pilot studies” for larger funding schemes and projects, and provide me with the opportunity to lead and manage my own projects whilst forming new international collaborative partnerships.

I’m ever so grateful to the donor community and Flinders University for the Impact Seed Funding for Early Career Researchers. Being awarded these funds greatly supports my ongoing development into becoming an independent and competitive researcher.

Thank you.

Congratulations, Petar!

CONGRATULATIONS to Flinders Uni Palaeo group student Petar Tomic who gave his final Honours seminar and viva online today! In his thesis Petar described a new placoderm (early jawed vertebrate) from the Devonian Gogo Formation in northern Western Australia.

Petar had to give an online seminar which must have been difficult, but he put in a lot of work to his thesis and should be proud of what he’s achieved. (And I’m looking forward to seeing his thesis turn into a published paper soon).

I hope you celebrate well tonight, Petar, the Honours experience is intense at the best of times, let alone during a global pandemic!

Tomic

 

A Virtual Congress

Despite this global pandemic raging all around us, during this first fortnight of May I have been taking part in a scientific conference from the comfort and safety of my own home. The 2nd Palaeontological Virtual Congress (PALAEOVC) showcases what I believe will become part of the new normal for scientific meetings.

PALAEOVC is developed exclusively in the virtual environment, meaning it is cheaper to hold (and attend), and can enable a higher number of researchers from every corner of the globe – which is great for those who can’t always travel to attend scientific meetings.

I presented a “virtual poster” which in essence consisted of 5 powerpoint slides showing one element of my research entitled “Endocast Anatomy of the Megalichthyid Tetrapodomorph, Cladarosymblema, Elucidated via Micro-CT” (which is a long-winded way of saying I’m looking inside the skull of a tetrapod-like fish called Cladarosymblema). This fish comes from the Carboniferous (~340 million years ago) of Queensland, Australia, and we’ve scanned two beautiful 3D preserved specimens, enabling me to look inside the fossils at the shape of their braincase.

PalaeoVC

PALAEOVC had several different sessions and different formats for presentations, invited guest presenters and even a virtual field trip to the Dolomites in northern Italy! The online platform provided space for discussion forums and it was great to be able to interact with the meeting and other attendees in your own time zone throughout the two weeks it was online.

I have to thank and congratulate the Scientific and Organising Committee for pulling PALAEOVC together which was particularly valuable during this time of global lockdown. I look forward to participating in the next one and envisage that this kind of virtual platform is likely to become more and more common in the future.

 

Upcoming BCSA talk

I’m looking forward to giving an invited presentation to Butterfly Conservation South Australia (BCSA) next month. The BCSA formed over 20 years ago to promote the conservation of butterflies and moths, and their habitat. Their members hold monthly meetings which begin with a “Butterfly of the Month” presentation, before an invited lecture from a diverse range of scientists (that’s where I come in).

I’ll be talking about one of my absolute favourite topics “Brain evolution of fossil fish and the first tetrapods“. I’ll summarise some of my previous work looking at brains of lungfishes, before moving on to more recent work on other groups more closely related to tetrapods (the first terrestrial vertebrates). There’ll be some spectacular fossils to be celebrated and I’m sure to say the work ‘endocast’ at least 100 times.

I always really enjoy the opportunity to talk about my research with the public so I’m very much looking forward to the night (even though we wont get to meet face-to-face due to current social distancing guidelines). However, if you ever need somewhere to learn about, identify, attract or breed butterflies, then apparently BCSA is the place to go!  

BCSA talk 2020

10 years of Rhinodipterus

Let me tell you about my favourite fossil lungfish.

Rhinodipterus is a long-snouted, tooth-plated lungfish known from the Mid-Late Devonian Period (roughly 390-360 million years ago). There were a handful of species of Rhinodipterus known from throughout Europe described during the mid 20th Century. However, a new specimen unearthed in 2008 from the Gogo Formation in Australia sparked my involvement and interest in this lungfish.

The Gogo Formation is particularly rich in lungfish fossils and this new find represented the 11th described species from this one locality. Most equivalent deposits may have just one or sometimes two species present, but clearly the lungfish were very diverse on the ancient Gogo reef! And interestingly, this European genus (Rhinodipterus) had for the first time appeared in a different part of the world, all the way over in Australia. This is something we refer to as ‘palaeobiogeographic distribution’. I named the new species Rhinodipterus kimberleyensis, to reflect the location where this fossil was found (the Kimberley region of northern Western Australia).

* CLEMENT, A. M. (2012) A new species of long-snouted lungfish from the Late Devonian of Australia, and its functional and biogeographic implications. Palaeontology 55, 51-71.

Aside from being a new species, the most interesting thing about Rhinodipterus are certain features of its skeleton that are missing from other lungfish at Gogo. Rhinodipterus has cranial ribs which suggests it may have been able to breathe air! Cranial ribs are mobilized during the air gulping action in living lungfish and so their presence (as well as a suite of other features) are used to infer this ability in fossil forms. While we know all living lungfish can breathe air, it is finds such as these that help us pinpoint when this feature first evolved in the fossil lineage.

* CLEMENT, A. M. and Long, J. A. (2010a) Air-breathing adaptation in a marine Devonian lungfish. Biology Letters 6, 509-512.

* CLEMENT, A. M., Long, J. A., Tafforeau, P. and Ahlberg, P. E. (2016b) The dipnoan buccal pump reconstructed in 3D and implications for air breathing in Devonian lungfishes. Paleobiology, 42(2), 289-304.

Furthermore, the specimen of Rhinodipterus that I described was so well preserved and uncrushed, it contained a near complete part of the skull called the braincase. As it’s name suggests, the braincase houses the brain inside the skull. Most lungfish fossils younger than the Devonian become more cartilaginous and don’t tend to fossilise particularly well (unlike bone, which is a harder and more durable material), so this is one of the most advanced fossil lungfish braincases known. Via CT-scanning and computer 3D-modelling I was able to create a virtual ‘endocast’ (mould of the internal cavity) of the braincase. These endocasts can give a lot of information about the early brain evolution in this most wonderful group of fishes (I’m not biased at all!) and help us to reconstruct brain morphology in extinct animals.

* CLEMENT, A. M., and Ahlberg, P. E. (2014) The First Virtual Cranial Endocast of a Lungfish (Sarcopterygii: Dipnoi). PloS One, 19 pp.

* CLEMENT, A. M., Strand, R., Nysjö, J., Long, J. A. and Ahlberg, P. E. (2016c) A New Method for Reconstructing Brain Morphology: Applying The Brain-Neurocranial Spatial Relationship In An Extant Lungfish To A Fossil Endocast. Royal Society Open Science, 8 pp.

Rhino_endo_updated_lateralR
A virtual cranial endocast of Rhinodipterus kimberleyensis in right lateral view.

As you can see, this single specimen of Rhinodipterus has been very valuable to my research over the years so I thought the least I could do was commemorate it with a blog post. Thank you, Rhino!

 

Fantastical Fish-a-pod’s Fish Fingers

It’s here, it’s here, Elpistostege is finally here!

What or who is Elpistostege, I hear you ask? Elpistostege is an ancient beastie that roamed the earth some 380 million years ago throughout parts of what is today Quebec in Canada. When fossils were first described it was thought they belonged to an ancient amphibian, before further finds suggested it was in fact a fish. The transition from fish (in the water) to the first land animals (with limbs and digits) was surely one of the greatest ever “steps” in evolution, and Elpistostege is perfectly placed to help us understand it.

KENNY Elpi reconstruction FINAL Aug26
Artwork by Katrina Kenny (https://katrinakennyartist.com.au/)

10 years ago, Prof Richard Cloutier from Université du Québec à Rimouski, discovered a new specimen of Elpistostege, and for the first time a complete skeleton of this animal was uncovered! The fossil is 1.6 m long and preserves a complete head, vertebral column and all the fins right up to the tail.

Richard invited some of the Flinders University Palaeontology group to work with him and his team in Canada on this exciting new fossil, which is where I come in (along with John Long and Mike Lee). The fossil was CT scanned at the University of Texas High-Resolution X-ray Facility so that detailed 3-D modelling of its skeleton could be done.

Alice, John & Richard 2019
Alice, John & Richard celebrating finishing the paper in 2019

Via this painstaking 3-D modelling of the scans (it took me months and months!), we revealed the internal bones of the pectoral skeleton (arm) including the presence of a humerus, radius, ulna, rows of carpal bones (e.g. your wrist bones), and other smaller bones (digits!). We have found the first fish fingers!

Excitingly, the digits are still contained within a fish fin. And as John and Richard put it in their recent Conversation article “This suggests the fingers of vertebrates, including of human hands, first evolved as rows of digit bones in the fins of Elpistostegalian fishes.” So next time you shake hands with someone (will we be doing that again?) or take a sip from a champagne flute (I’ll be doing that tonight), you know who you have to thank.

Read the full article in Nature here: https://www.nature.com/articles/s41586-020-2100-8.pdf

  • Hear my radio interview on The Wire, with Lachlan McPherson here.

Rewriting evolution – our fishy origins

Tonight, Professor John Long, Strategic Professor of Palaeontology, will talk about “Rewriting evolution – our fishy origins” at the Alere Function Centre, Flinders University, as part of the BRAVE lecture series.

BRAVE

Come and hear about how the beginnings of the human body plan first appeared in fishes, deep in geological time. “Professor Long will discuss his thesis that the big steps in human evolution took place well before fishes left the water to invade land. This research provides a new perspective on humans’ evolutionary story; one which comes from looking up from the water’s edge, not looking down from the trees.

I’ll be on the panel for the discussion to follow John’s presentation, alongside Associate Professor Paul Willis (founder and CEO, Media Engagement Services) and Associate Professor Diego Garcia-Bellido (University of Adelaide and South Australian Museum).

IMG_4600
Paul Willis, Diego Garcia-Bellido, Alice Clement & John Long at Flinders BRAVE lecture

Drinks and canapes from 5:20, lecture begins at 6pm.

This event is free to attend but register your attendance here: https://www.eventbrite.com.au/e/brave-rewriting-evolution-our-fishy-origins-tickets-95533279611