A tale of two Joshuas…

Nope, I am not about to talk about figures from the Hebrew Bible (you’re certainly in the wrong place if that is what you’re after), but instead some fantastic student-led work that was published recently by two of my students.

Firstly, Joshua Bland, who was an Honours student of mine at Flinders University during 2022-23, has published a paper in the mulitidisciplinary journal iScience with the title “Comparison of diverse mandibular mechanics during biting in Devonian lungfishes“.

He worked on fossil lungfishes from the Late Devonian Gogo Formation, of northern Western Australia, which are beautifully preserved in 3D. Gogo is an interesting site for lungfishes, as this ancient tropical reef preserves the most diverse assemblage of lungfish species in any space or time from throughout their 400 million year history.

Graphical abstract from Bland et al. (2025) https://www.sciencedirect.com/science/article/pii/S2589004225012313

The lungfish at Gogo are taxonomically diverse (many species), but also morphologically disparate (anatomically different from each other). We wondered how this may impact function, did their jaws work biomechanically differently from one another?

To answer this question, Josh used a technique adapted from engineering, called Finite Element Analysis (FEA). FEA is a computer-based method used to predict how structures respond to external forces by calculating the stress and strain within small, divided elements of the object. The first use of FEA in palaeontology was by Emily Rayfield and colleagues on the skull of a large theropod dinosaur in 2001, so its use remains quite recent for the field, and our study is the most comprehensive application to fossil fishes published thus far (yay!).

Generalised methods figure from Bland et al. (2025) showing stepwise
process to solve Finite Element Models of fossil lungfish mandibles (lower jaws) during biting.

Together with our co-authors, Hugo Dutel, John A. Long, Matteo Fabbri, Joseph Bevitt, and Kate Trinajstic, and our very own FEA guru, Olga Panagiotopoulou, we found a diversity of stress and strain experienced by our lower jaw models, with some surprising results. This diversity of jaw morphology and biomechanics seen among the lungfish at Gogo may have been one of the reasons driving their great success. Different lungfish were adapted for eating very different things and so weren’t in resource competition with each other.

Our comprehensive dataset offers the most detailed quantification of biting performance in any fossil fish thus far, providing biomechanical evidence for diverse feeding adaptations and niche partitioning within Gogo lungfishes.

And then to add to the excitement, another paper was published in the same week from another Joshua! This time it was current PhD student, Joshua Batt, publishing his first peer-reviewed paper in the Journal of Vertebrate Paleontology with “New rhizodontid (Tetrapodomorpha, Sarcopterygii) material from Romer’s gap (Tournaisian) of the Ballagan Formation (Scotland, UK).”

Working together with Dr Tom Challands, from the University of Edinburgh, researchers at Flinders University have been busy preparing and describing a real beast of a fish from the Early Carboniferous of the UK. The specimen was extracted by Tom and colleagues from Burnmouth in Scotland, but 10 or so large blocks of material came to Australia in 2020 for further study. Painstaking mechanical preparation has been done by Carey Burke and revealed what is likely to be one of, if not the most, complete articulated rhizodont fish known.

John Long, Carey Burke and Josh Batt inspect a specimen of fossil rhizodont at Flinders University.

Rhizodonts were large predatory lobe-finned fishes that lived throughout the Devonian and Carboniferous periods, usually in freshwater or estuarine environments. Some are thought to have grown as big as seven meters in length and they had very big teeth. Not a fish I would like to swim with!

Josh started working on this material for his Honours project during 2024, and there still remains a lot of it to be formally described, especially post-cranial material, but this first “rapid communication” paper presents the “main skull block”. Is this thing more beauty or beast… (perhaps beauty really is in the eye of the beholder?)

Image from Batt et al. (2025) JVP showing the dorsal view of NMS G.2025.10.1.1.

Needless to say, I felt very proud seeing two of my students have their first peer-reviewed publications come out. I expect more good things to come from both of them.

Want more? You can find both of these fantastic papers via the links below:

Canowindra Capers

I have just returned from a week in NSW central west with ~25 students from Flinders University. Our fieldtrip visited two significant vertebrate palaeontology sites in the area, the Wellington Caves, which have captured the bones of mega (and mini-) fauna over the last few million years in an ancient limestone cave complete with sparkling geological “Cathedral” features.

Just 90 minutes from Wellington lies the township of Canowindra, a site of exceptional preservation (lagerstätte) from the Late Devonian (Famennian) age. I’ve known about this site since I first started studying fossil fish, but had somehow never visited before now.

An ancient meandering river system is thought to have captured a mass of fish in a channel cutoff from the main river, which eventually dried up capturing thousands of fish in a shrinking drying billabong 363 million years ago. Evidence of the site was first recognised when a slab of rock was upended revealing curious marks underneath during the 1950s. A Canowindra local, and then the curator at the Australian Museum in Sydney could see these were unusual curious fossil fish from days gone by.

Later, Palaeontologist Dr Alex Ritchie of the Australian Museum, conducted an excavation in 1993, at that time he and his team collected approximately ~3000 fish specimens from a single layer within the Upper Devonian Mandagery Sandstone. Many of these specimens are now on display in the FANTASTIC Age of Fishes Museum.

The site itself is Late Devonian (Famennian) in age, capturing a moment in time ~363 million years ago. More than ~3000 fossils have been unearthed from a single rock layer within the Upper Devonian Mandagery Sandstone.

The accumulation of fish fossils from drought conditions points to a single palaeocommunity, with trace fossils such as ripple marks suggesting a fluviatile (billabong) environment. The preservation of the Canowindra fauna indicates that the fish became isolated in a temporary pool of water, which rapidly dried up. The concentration of all the fish packed upon one another in the layer suggests a mass mortality event due to these dry conditions.

The original fossil fish dig site.

So far there are eight species of fossil fish recognised from the Canowindra site, with one of those still awaiting formal description. The fauna is dominated by the two named species of antiarch placoderms (jawed, armoured fishes), Bothriolepis and Remigolepis, comprising some 97% of the fauna! The other placoderm, Groenlandaspis, an arthrodiran placoderm, is much rarer, with just ~50 specimens recovered. The sarcopterygians (lobe-finned fishes) are even rarer still, with the remains of approximately 20 individuals across five genera, found so far.

We were warmly welcomed to Canowindra by the new owners of the property containing the original fossil fish site, David and Aleysha McGrath, as well as by the staff of the Age of Fishes Museum. We kicked the week off with a public talk held at the bowling club where I spoke about “The Devonian Age of Fishes, from an Australian Perspective”. It was fabulous to see so many locals turn up for the event and there were many good questions and curiosity about the future of the site (I believe it is in very good hands).

David, Aleysha and Alice on site at the original fossil fish dig site.

It was a delight to take the students out into the field to see the site of the original dig and even identify a few previously undiscovered fossils from big blocks of the sandstone. The site is dominated in abundance by the placoderms, but we were shown an enigmatic new specimen that looked decidedly lobe-y. There are five species of lobe-finned fish known from the site, but these are rare occurrences. At first, we thought it might be a large individual of a long-snouted lungfish, but after taking a silicone impression of the specimen (using a special putty) we could identify it as a large individual of Mandageria fairfaxi, the biggest beast from the ancient waters of Canowindra. Mandageria holds the special honour as being the state fossil emblem of NSW!

Read more: Incidentally, do you know your own state fossil emblem?

ACT NSW QLD SA VIC WA (get your act together TAS & NT!)

Austin, Alice and Ramon taking a silicone mould of a fossil still encased in the rock.

After a morning in the field, we took the students for an afternoon at the fantastic Age of Fishes Museum. This is a really fabulous local museum where real specimens are on display showing the exceptional preservation of hundreds of whole fish bodies preserved jam-packed upon one another in their final moments. The high quality of the interpretive material and exhibits, truly welcoming staff, and sunny picnic spot outside make it well worth a visit! Our students perused the gallery and we learnt to identify and distinguish the different fish known from Canowindra. We spoke about the distribution and relative abundance of the various groups, and what palaeoecological and biogeographical implications could be drawn from that. We rounded out our afternoon with a look through the additional slabs held in the storage shed, with a surface scanning demonstration and practise session.