Plastic reptile brains

Want more brain power in your life? I sure do, so I’m super pleased to announce that we found out that our Australian Research Council Discovery Project grant was funded last week! The project title is: Plastic brains: Neural adaptations to changing environments in reptiles, and we have three years of funding to complete the project.

BUT ALICE, I may hear you ask, these are not fish? No, you are quite correct, these are not fish (or just very highly derived fish), but I’m really interested in trying to understand brain evolution in all of the so-called “lower” vertebrates and particularly see how they change over major environmental shifts.

The project is really the “brain child” of the incredible Jenna Crowe-Riddell (La Trobe) and I’m stoked to be involved (we are pictured above enjoying some home-grown veggies in the sunshine). I’m also looking forward to working with all of our co-investigators Mike Lee (Flinders), Shaun Collin (La Trobe), Kate Sanders (University of Adelaide) and Alison Davis-Rabosky (University of Michigan).

We’ll be exploring macroevolutionary and ontogenetic patterns of brain evolution in reptiles, quantifying neuronal densities, and investigating the effects of temperature on brain development with a focus on some key Australian radiations such as elapids (snakes) and agamids (dragon lizards).

They may not be fish, but I’m very excited to investigate how the brains of Aussie snakes and lizards have evolved in response to past and ongoing environmental change using some cool techniques like DiceCT (for imaging soft tissue anatomy), Geometric Morphometrics (to capture complex shape) and some cool phylogenetic analyses courtesy of the phylo master (Mike).

Protocol to diceCT scan including a comparison of CT-scan pre & post iodine staining and 3D render of neuroanatomy showing specific digitally dissected brain regions (Callahan, Crowe-Riddell, et al., 2021).

Commiserations to all who missed out on DP grants this round. With a success rate consistently lower than 20% there are many fantastic and worthy projects that fail to secure funding. Total funding (in real terms, not due to inflation) is the lowest in years this round (at least the last 8 years, see graph on left below). I think Australia can, and needs to do better in funding more research and development to keep up with other (particularly OECD) countries. Additionally, as a female EMCR lead investigator (red line in graph on the right), Jenna is here kicking the trend of most funding being awarded to male level E Professors (aqua line) and so this effort is particularly impressive! Exciting times ahead for Jenna and for reptile brains!

IPC6 in Thailand

I’ve just returned from a week away in Khon Kaen in northeastern Thailand where I attended the 6th International Palaeontological Congress (IPC6). The IPC meetings are held every four years since the first meeting in Australia in 2002. I wasn’t at that meeting, but I’ve been lucky enough to attend the previous three meetings prior to Thailand this year (IPC3 London, IPC4 Mendoza, and IPC5 Paris).

IPC brings together all sorts of palaeontologists, those who work on plants, trace fossils, micro fossils, invertebrates and vertebrates, to communicate their latest research and findings. The theme of the meetings was “From Gondwana to Laurasia” reflecting the great geological and palaeontological diversity of Thailand’s terranes. (Gondwana and Laurasia were the southern and northern supercontinents respectively that formed Pangaea during the late Paleozoic and early Mesozoic).

The “fish” people at IPC6 2022 in Khon Kaen, Thailand.

There were more than 400 participants from 40 countries participating in over 30 differently themed sessions. The disappointingly low representation of women (let alone non-binary) keynote and plenary talks was noted (only 2 out of 18! Do better palaeo!), and some insensitive remarks at the final conference dinner highlighted that we still have far to go to reach gender equality in palaeontology.

However, I’m very pleased to say that I had the honour of giving the keynote for the “Digital Palaeontology” session, as well as giving a second talk about coelacanths in the “Palaeozoic Fish and Early Tetrapods” session.

Aside from all the talks and posters, we were kept busy with conference dinners and music performances and optional mid-conference daytrips to see nearby Khmer temple ruins (spectacular Phimai) and attend the local Loy Krathong (Lantern Festival) celebrations in Khon Kaen.

As always, it was fantastic to meet up with old colleagues and meet new ones. There were many projects discussed over breakfast, lunch and pre-dinner drinks throughout the week which can be surprisingly productive! I’m very much looking forward to the next meeting in Cape Town 2026 (thanks Anusuya!)

Living fossils

Do you have a favourite “living fossil“? The term was coined by Charles Darwin in his book On The Origin of Species in 1859 to describe living organisms that appeared unchanged from their extinct fossil relatives. He was describing animals such as the Nautilus (cephalopod) and Lingula (brachiopod) that he observed were “some of the most ancient […] animals do not differ much from living species.”

The term has gone on to describe organisms that seemed to have stopped evolving either in their genes (molecular) or form (morphological), or those with particularly long lineages. The term can also be somewhat problematic when used to describe animals that appear to have stopped evolving, but may just be doing so at a slowed pace, or in ways not visible to the human eye.

I wrote an article published this week in The Conversation, From coelacanths to crinoids: these 9 ‘living fossils’ haven’t changed in millions of years, listing my nine favourite marine living fossils. Top of the list is the enigmatic and beautiful coelacanth, of course!

I’ve had a few radio interviews in response to the article, and it has even been translated into Japanese on the Arkive 4 Ones website. Sugoi desu ne!

This article was all about curious “living fossil” sea creatures, but I’d love to follow up with a freshwater and terrestrial version one day. What would make your list?

Fossilised body organs in fish

How old do you think the oldest fossilised heart is? 1 million years? 100 million? More? We found a 380 million year old fossilised heart, as well as stomach, intestine and liver in ancient jawed fishes, published today in the journal Science. (Previously the oldest known fossilised heart was described from a measly 100 million years ago…)

Finding soft tissue preserved in fossils is rare, and finding 3D preserved fossils is remarkable, so the combination of these in 380 million year old animals is mind-boggling! These fish are the ancient armoured placoderms from the famous Devonian (359-419 million years ago) Gogo reef lagerstätten (meaning site of exceptional preservation) in northern Western Australia.

Gogo fish diorama at WA Museum Boola Bardip. Credit: Curtin University

Powerful imaging techniques such as synchrotron scanning by the European Synchrotron Radiation Facility in France, and neutron tomography at the Australian Nuclear and Science Technology Organisation (ANSTO) in Sydney (Australia) enabled us to see inside the specimens while they were still embedded in limestone and construct 3D models of the bones and soft tissues inside. I still remember the day sitting at ANSTO with lead author Prof. Kate Trinajstic and beam scientist Dr Joseph Bevitt looking through the latest neutron scans when we found one of the heart specimens in a placoderm called Compagopiscis.

Joseph Bevitt, Alice Clement and Kate Trinajstic at the ANSTO neutron facility in Sydney.

Importantly, the shape and position of the heart (the oldest ever found!) signifies an important step in evolution of the vertebrate body plan, and the lack of lungs suggests these organs only evolved once later on in the bony fishes.

It was so exciting to be included in this project with a kick-ass team spanning Australia, Sweden, and France with my co-authors Kate Trinajstic, John Long, Sophie Sanchez, Catherine Boisvert, Daniel Snitting, Paul Tafforeau, Vincent Dupret, Peter Currie, Brett Roelofs, Joseph Bevitt, Mike Lee and Per Ahlberg.

These Gogo fossils just keep on giving! If you would like to learn more, you can read an article by Kate and John in The Conversation or this one from Cosmos Magazine (complete with a few extra dorky pics of me “science-ing”.

Palaeo Jam!

Haven’t had your palaeo fill this National Science Week yet? Come along on August 25th for the inaugural recording of PALAEO JAM, a new Australian palaeontology podcast from Michael Mills of Heaps Good Productions.

“Palaeo Jam is a podcast exploring a range of issues in science and the community, through the multidisciplinary aspects of, and public fascination with, palaeontology. It is an Australian based palaeo podcast with this initial launch and live record at Flinders University. For the live record, two episodes will be recorded in front of a live audience, followed by a QandA.”

Episode 1- “What’s the point of palaeontology?” featuring Dr Aaron Camens, and PhD Candidate Phoebe McInerney.

Episode 2- “Life as a palaeo mum” with Dr Alice Clement and Dr Vera Weisbecker.

***LISTEN ON PODBEAN HERE***

Drinks and other goodies available on the night. Register your attendance here: https://www.eventbrite.ca/e/palaeo-jam-podcast-launch-tickets-376247826377?aff=ebdssbdestsearch&keep_tld=1


Fossil lungfish “brains” in eLife

Our latest article “Morphometric analysis of lungfish endocasts elucidates early dipnoan palaeoneurological evolution” was published yesterday in eLife.

In the way that many projects tend to go, the work for this article is several years in the making. I developed the seed of the idea during my time at Uppsala University (Sweden), and have been collaborating closely with Dr Tom Challands (University of Edinburgh) for several years to bring it to fruition. Together, Tom and I pooled our lungfish endocrania to more than double the number of those with “endocasts” known.

A cranial endocast is the internal space within the skull where the brain sits. As only the hard, bony parts of animals tend to fossilise we rely on the shape of these spaces to make inferences about the (now long gone) brain within.

Using synchrotron and micro-CT scanning technology, we were able to scan six new lungfish fossils to create virtual models of their endocasts. The fossils need to be exceptionally-preserved in 3D to be able to conduct these analyses. The fossils came from different sites from around the world (Australia, USA, Russia and Germany), but all hailed from the lungfish “heyday” of the Devonian Period (359-419 million years ago).

By combining these six new fossil models with all of the other lungfish endocasts known were were able to compile a dataset of 12 taxa which we then measured. The skulls of Devonian lungfish are highly variable in shape, and so we predicted that different endocast (brain) regions would undergo elongation as the external skulls changed shape.

Figure 12 from the eLife paper showing 10 fossil lungfish endocasts.

Along comes our heroic collaborator, Prof. Richard Cloutier (UQAR), who then had the unenviable task of making sense of our messy measurements and conducting some impressive morphometric analyses (a way of quantifying shape) despite our dataset having several missing variables (something not usually accommodated well in many morphometric analyses). We used several methods, including Bayesian Principal Component Analyses (BPCA) and PCA for incomplete data (InDaPCA) to untangle how the shapes of the endocasts differed from one another.

Figure 10 from the eLife paper showing a BPCA plot.

Our findings showed that contrary to our hypothesis where we thought different brain regions would tend to elongate within long skulls, most of the elongation (regardless of skull shape) tended to happen in the olfactory (sense of smell) region. We consider that sense of smell has remained an important sense throughout lungfish evolution.

We also uncovered some interesting things happening within the labyrinths (inner ears). The shape of inner ears can give a lot of information about an animal related to its sense of hearing, but also how it moves (locomotion). More investigation needs to be done but this may point to differing sensory requirements as lungfish evolved from deep sea animals to those living closer to shorelines in freshwater environments.

Ultimately we are continuing to learn more about brain evolution in this most fascinating group, the lungfish, which can in turn aid our interpretation of other groups -including our earliest fishy ancestors as they took the leap from water to land. Big thanks are due to all co-authors Tom Challands, Richard Cloutier, Laurent Houle, Per Ahlberg, Shaun Collin, John Long, as well as the editorial and reviewing team at eLife. If you would like to know more then I encourage you to read the article directly from eLife. All scan data is freely available for download from MorphoSource or Dryad.

Palaeo-matrescence

I’m not sure that I have much wisdom to impart as I’m only writing this as a very new “parent in palaeo”. My son is just 9 months old and I’m imminently returning to work following maternity leave. It has been, as everyone says, a life-changing time and I have (mostly) enjoyed my days at home with the little one.

Before going on maternity leave I expressed some concerns about how being a mother in palaeontology/science/academia might potentially impact my career trajectory. I knew I worked in a male-dominated field, but it never felt more apparent than when I became pregnant. I wanted to seek advice from colleagues who had navigated the same journey as me, but it was difficult to find people in the same boat. I could see plenty of “parents in palaeo”, but looking for mothers (in the traditional, biological sense) was a harder task. Where are they all?

Alice at ~8 months pregnant (2021)

Unfortunately the career stage when most people become parents is during the vulnerable EMCR (Early – Mid Career Researcher) years when the majority of researchers are still navigating short-term, insecure contracts. It is no surprise then that it is during the EMCR stage we see the greatest effects of the “leaky pipeline”. (And relatedly, the numbers of women progressing from junior to senior levels suffers from what I’ll call the dreaded “scissor graph disappearing act”). I have no doubt that any time away from work compounds differences in output in our very competitive funding landscape and can therefore influence potential future success. The recent mothers I could see in STEM (in Australia particularly) were few and far between, and most of them continued to juggle insecure work.

Furthermore, years of insecure work throughout one’s late 20s and 30s can influence the decision about when to start a family. This was certainly the case for me, I had hoped for some job security prior to becoming a mother, but in the end I felt like I couldn’t wait much longer. I had my first child at age 37 and I don’t know if we will have any more. I do consider that if I had had secure work earlier in my career I might have started child-bearing younger and potentially had more children. In this way, a choice to pursue a career in science can directly impact one’s fertility.

Alice at home with baby Edvin

Similarly, academia often requires workers to relocate to new cities, new countries, new continents, taking people away from their traditional support networks such as extended families. This may influence when, and in what capacity, a parent might return to work after the birth or adoption of a child. Our families are based in Melbourne and Sweden respectively which renders our “village” pretty distant when we might otherwise call upon their help.  

Many people told me that I would “feel differently” about work once I became a mother (I note that no one ever said this to my partner, Niels). In some ways I think I was lucky that my work is a passion of mine, and being able to remain connected was a positive for me. Being a full time parent at home with a baby can be isolating and relentless in the day-to-day, and being able to check in occasionally with students and colleagues gave my brain a welcome escape from nappies, tantrums and breastfeeding. However, there were also times when I felt overwhelmed and frustrated to not be able to contribute as I would have liked, either due to the lack of time or headspace (usually both). Science is a highly collaborative pursuit, and the cycles of grant deadlines, student projects, and research papers doesn’t take a pause just because you do.

Alice with Edvin (6 months)

I’m lucky to have good support from my supervisor, colleagues and university so I feel positive about my immediate future. The long-term effects of choosing to have a family remain to be seen but I’m hopeful that our government and institutions can better accommodate working parents in the years to come.

I lived and worked in Scandinavia for a few years early in my career and saw how their more generous parental leave policies, with time allocated to both parents, and highly subsidized/universal childcare supported families and careers. I believe that Australia can do a lot better in this respect to improve equality at home and in the workplace. It is time for fathers and other non-birthing parents to take more time out of their careers to care for children too.

However, far from “changing priorities” and “feeling differently” about my career, I absolutely relish the idea of returning to work. I hope that by writing this piece I am increasing the visibility of at least one mother in STEM who is doing her best to (hopefully!) thrive as a “parent in palaeontology”.

Gogo grant funded!

Father Christmas came early this year! Our Discovery Grant “The Devonian Gogo Fauna: Diversity, Palaeoecology and Global Significance” from the Australian Research Council (ARC) was funded! This grant gives us three years of funding for research and to support students and other staff associated with the project.

John Long (Flinders Uni), Kate Trinajstic (Curtin Uni) and I are Chief Investigators, and we’ll be collaborating with a fantastically diverse range of international partner investigators including Carole Burrow (Queensland Museum), Per Ahlberg (Uppsala University), Derek Briggs (Yale University), Zerina Johanson (Natural History Museum London), Christian Klug (University of Zurich) and Richard Cloutier (University of Quebec).

Prof. John Long, Dr. Alice Clement, and Prof. Kate Trinajstic attending the International Symposium of Early and Lower Vertebrates in Poland, 2017.

The Late Devonian Gogo Fm. in Western Australia (380 myo) is one of the richest and best-preserved assemblages of fossil fishes & invertebrates on Earth. We will reconstruct the trophic relationships of the reef and test the resilience of the ancient reef ecosystem.

Additionally, we will work with local indigenous stakeholders to assess the heritage significance of the site. We aim to develop a long-term management plan to protect and conserve this amazing site and help to grow geotourism in the region.

I believe that Gogo is the best fossil fish site in the world and I can’t wait to get back there in the coming years with our collaborators, and see what we can achieve with this crack team of researchers we’ve assembled. Merry Christmas to us, indeed!

Dr. Alice Clement with a fossil find at Gogo in 2008.

New paper on tetrapod-like fish from Queensland

Hello! I’m taking a brief break from my maternity leave to tell you about my latest paper, published last week in the Journal, PeerJ; A fresh look at Cladarosymblema narrienense, a tetrapodomorph fish (Sarcopterygii: Megalichthyidae) from the Carboniferous of Australia, illuminated via X-ray tomography.

Four panels: a photo of the specimen, a radiograph of the specimen, a tomogram (slice) of the specimen, and a 3D model of the specimen. Image credit: Alice Clement.

In my paper we use microCT and synchrotron technology to image some spectacular 3D fossils of a fish known as Cladarosymblema from about 330 million years ago in what is today known as Queensland, Australia.

Cladarosyblema was a type of tetrapod-like fish known as a ‘megalichthyid‘. These fish grew to large sizes, lived in freshwater environments, and would have been fearsome predators. They were one of the few tetrapodomorph groups that survived the end Devonian extinctions, and persisted up until the Permian Period (299-252 mya). Cladarosymblema is the only megalichthyid known from Australia, and one of just two known from the ancient southern supercontinent, Gondwana.

Cladarosymblema was originally described in 1995 from several specimens, but using scanning technology we were able to uncover much of its internal anatomy that had until now remained hidden. In particular we could describe the gill arch skeleton, parts of the shoulder girdle, vertebrae and upper roof of the mouth bones (palate).

Additionally, we were also able to isolate the cranial endocast from Cladarosymblema, which gives insights into the size and shape of the brain of this animal. The area for the pituitary gland (so-called the master gland) is relatively large, suggesting a significant role in regulating various important endocrine glands. The overall shape of the endocast is more similar to that of early terrestrial vertebrates (tetrapods) than to most of the fish left living in the water. Was it some of these adaptations that enabled Cladarosymblema’s relatives to colonise land?

Furthermore, the membership of the ‘megalichthyids’ has been controversial, with several recent studies finding conflicting results. We ran a phylogenetic analysis (analysis of relationships) and found that the megalichthyids form a natural clade (are monophyletic).

Section of the evolutionary family tree showing that megalichthyid fishes form a natural clade.

I want to thank the Queensland Museum for allowing us access to the beautiful specimens, as well as all of my co-authors, reviewers, and the editor who handled the paper at PeerJ. All of the scan data and 3D models are available at MorphoSource, and the phylogenetic matrix can be accessed on MorphoBank.

Cladarosymblema narrienense head restoration in right lateral view. Image: John Long.

A different kind of project

I’ll be stepping back from my monthly updates a bit as I prepare to go on maternity leave next week. It’s exciting, terrifying & overwhelming, and I understand it will change the life of me and my partner forever. Bubba is due in just over two weeks!

This is what a scientist looks like (8 months pregnant).

I’m all too painfully aware of what the statistics say and how the penalty of motherhood continues to impact women disproportionately compared to their male counterparts (fathers get promoted, while women are pushed out via the #leakypipeline).

Figure 1. Academic profiles by gender; natural and physical sciences 2007.
Source: DEEWR Selected Higher Education Student Statistics 2007; Department of Education,
Science and Training, Special Report, FTE Staff in AOU Groups, 2007.

Even today, it was confronting to look around and struggle to find role models who had become mothers and managed to succeed to senior levels in STEM #WomeninSTEM (although I’m inspired by the few exceptions I do see).

I did also manage to be #PregnantInTheField relatively early on. Very doable (with a few extra toilet breaks and early nights to bed, and some extra loose pants!) I did miss being able to enjoy a glass or two of red by the campfire at the end of the day, however.

Dr Clement, pregnant in the field, holding a fossil find.

I am really hopeful that things continue to improve and that my career isn’t too negatively impacted by choosing to have children. Sometimes I can’t help but wonder what is the point of all the initiatives to encourage girls into STEM if we don’t retain women in STEM?