The Fossil Files

Fossilised vomit can provide direct, yet disgusting, evidence of past ecosystems and interactions between long extinct organisms. This week we take a look at "the earliest terrestrial regurgitalite" from the early Permian of Germany. This prehistoric puke helps us to reconstruct who was eating what, including the Dimetrodon, the famous sail-backed synapsid.

This week's paper is "Early Permian terrestrial apex predator regurgitalite indicates opportunistic feeding behaviour" by Arnaud Rebillard and colleagues, published in Scientific Reports in February 2026. https://doi.org/10.1038/s41559-025-02929-8

Another 'paper' we mention is "Unusual Arrangement of Bones at Ichthyosaur State Park in Nevada" by Mark McMenamin published in 21st Century Science & Technology in 2012 (no doi). Another that we mention but couldn't remember the title of was "Carboniferous recumbirostran elucidates the origins of terrestrial herbivory" by Arjun Mann and colleagues https://doi.org/10.1038/s41559-025-02929-8

Wide screen art by Sophie Fernandez.

Getting a fossil species named after you is an unsual way to acheive quasi immortality, especially so for a species of human. In this preview of our second bonus episode we take a look at the weird, and often tragic lives of 5 people who have given their names to species of fossil humans, ranging from mad Austro-Hungarian aristrocrats to rampant imperialists and German pastors. Along the way we ask if we can learn some lessons from this ecletic bunch, and explore the fascinating new science revealing the face of human ancestors.

The full episode is available via our Patreon.

The paper tangentially discussed this week is "Denisovan mitochondrial DNA from dental calculus of the >146,000-year-old Harbin cranium" by Qiaomei Fu and colleagues published in Cell in July 2025 https://doi.org/10.1016/j.cell.2025.05.040.

Wide screen art by Australian Museum.

How and when did mammoths go extinct? This week we take a look at two bizarre mammoth related "fossil fails". The first is some unexpected results from from the "adopt-a-mammoth" scheme, a fascinating citizen science project trying to find the youngest mammoth fossil to date their extinction. In the second, we take some time to consider the most bizarre hypothesis of mammoth extinction yet: did they sneeze themselves to death as a result of horrible allergies and then get "snuffed out"? Get your skepticism at the ready. The papers we discuss this week are "Adopted mammoths from Alaska turn out to be a whale's tale" by Matthew Wooller and colleagues published in the Journal of Quaternary Science in December 2025 https://doi.org/10.1002/jqs.70040 and "Sense of smell reduction as factor for mammoth's and other mammals extinction" by Gleb Zilberstein and colleagues published in Earth History and Biodiversity in September 2024 https://doi.org/10.1016/j.hisbio.2024.100008.

Relevant past episodes of The Fossil Files are #10 "Fossil Fails: A Precambrian beehive and dinosaurs on the moon" and #3 "Is de-extinction a scam?".

Wide screen art by James Havens.

How and when and why do you become a palaeontologist? Biology, Geology, something else? Childhood, undergraduate, PhD? Susie and Rob discuss the different routes and offer their advice and experiences. This is a preview of our first bonus episode. To hear the rest of the episode, support us on our Patreon https://patreon.com/FossilFiles

The idea that dinosaurs were all scaley beasts got a massive challenge in 2000s when a variety of feather-like structures were found in fossils in China and other places. An even greater diversity of weird coverings have been found since then, most recently an iguanodontian covered in spines. This week we take a look at the porcupine looking Haolong dongi and what this means for dinosaur evolution. We also take a look some amazing trace fossils from the Permian of Germany, so detailed they even show the scales of an early reptile, including its cloaca. That's right, an improbable fossil butthole. Two tales of suprising scales.

This week's papers are "Cellular-level preservation of cutaneous spikes in an Early Cretaceous iguanodontian dinosaur" by Jiandong Huang and colleagues published in Nature Ecology & Evolution in February 2026 https://doi.org/10.1038/s41559-025-02960-9 and "The earliest reptile body impressions with scaly skin" by Lorenzo Marchetti and colleagues published in Current Biology in March 2026.

Wide screen artwork by Fabio Manucci.

What (and when) is an animal? They are thought to have first arrived about 500 million years ago and immediately underwent an explosive diversifcation at the beginning of the Cambrian. When and how this important event took place has always been hard evolutionary problem to solve: fossils with the necessary preservation of soft-tissues are rare and limited. Two finds from China blow open new windows into this episode.

The first is a new site from just before the Cambrian. It yields all sorts of typical Ediacaran weirdos, but preserved in a way that we don't usually get to see them. This not only sheds new light on what was going on before the Cambrian, but also means we can begin to look at the origin of animals in a new way.

The second is a new site from 27 million years after Cambrian began. The quality and diversity of the new fossil finds is massive, so much so that it could be considered a new "Burgess Shale", the archetypal and famous Cambrian deposit with exceptional preservation.

In a final after-thought, we take a look at sponges and their evolutionary relationships. A new phylogeny helps us to understand why we have such a limited fossil record of early animals: they were likely completely squishy and devoid of a skeleton.

Together a more complete picture of our distant animal origins is emerging and how palaeontology can help us, even through the limited windows that we have.

The first paper is "The terminal Ediacaran Tongshan Lagerstätte from South China" by Jin-bo Hou and colleagues published in Nature Ecology and Evolution in November 2025. https://doi.org/10.1038/s41467-025-65176-2

The second paper is "A Cambrian soft-bodied biota after the first Phanerozoic mass extinction" by Han Zeng and colleagues published in Nature in Janaury 2026 https://doi.org/10.1038/s41586-025-10030-0

The final paper is "Independent origins of spicules reconcile paleontological and molecular evidence of sponge evolutionary history" by Maria Eleonora Rossi and colleagues published in Science Advances in January 2026 DOI: 10.1126/sciadv.adx1754

Wide screen art by Dinghua Yang.

Sometimes the answer to palaeontological mysteries can actually be right in front of our faces, if only we know how, or where, to look. This week we take a look a two cases by the Fossils Files' own Susie, Rob and Jane. Firstly, we reveal how the eyes and skeletons of early vertebrates were right in front of us, hidden in Silurian Scottish fish fossils, but only observable when we applied high powered X-ray analysis to them. Secondly, we look at the mystery of the missing European ceratopsian dinosaurs. Turns out these horned dinosaurs were there all along after a new discovery from the Cretaceous of Hungary shook up the family tree.

So this week the Fossil Files gets a bit self-involved as we discuss about our own research. The first paper was by Jane Reeves (behind the scenes contributor to The Fossil Files), with Rob Sansom and colleauges in Manchester and California, published in Proceedings of the Royal Society B in January 2026 "Early vertebrate biomineralization and eye structure determined by synchrotron X-ray analyses of Silurian jawless fish" https://doi.org/10.1098/rspb.2025.2248

The second paper was by Susie Maidment, Richad Butler, Steve Brusatte, Luke Meade, and colleauges in Hungary, Germany and Romania published in Nature in January 2026 "A hidden diversity of ceratopsian dinosaurs in Late Cretaceous Europe" https://doi.org/10.1038/s41586-025-09897-w

Another paper we mention when talking about fossil fish came out the same week of Jane's paper in Nature by Xiangton Lei and colleagues published in Nature in January 2026 "Four camera-type eyes in the earliest vertebrates from the Cambrian Period" https://doi.org/10.1038/s41586-025-09966-0

Wide screen art by Matt Dempsey.

Life nearly died 252 million years ago in a mass extinction at the end of the Permian. It was long thought that it took 10s of millions of years into the Triassic for life to recover and get back to a 'new normal'. That was until a new and very muddy fossil site from the high Arctic revealed a staggering diversity of predators and tetrapods in the earliest Triassic seas. This week we take a look at the new findings and its implications for life's ability to recover from major extinctions.

This week's paper is "Earliest oceanic tetrapod ecosystem reveals rapid complexification of Triassic marine communities" by Aubrey Roberts, published in Science in November 2025 DOI: 10.1126/science.adx739

An accessible summary can be found here.

You can see lots of nice pictures and get some extra context from some slides by Jørn Hurum here

Wide screen art by Robert Back.

Lead is a well known pollutant affecting human health over the course of our urbanisation and industrialisation. But what about before this? Analysis of a range of fossil hominid teeth from the Pleistocene reveals that lead poisoning might have been a ubiquitious part of our deep evolutionary history. Furthermore, lab experiments looking at the effect of lead exposure on human and neanderthal brain development reveals the interplay between this pollutant and 'the language gene' (FOXP2). Together, this suggests that the development of language, socialisation and ultimate evolutionary success of humans might be related to our ability to overcome lead poisoning.

This week's paper is "Impact of intermittent lead exposure on hominid brain evolution" by Renaud Joannes-Boyau and colleagues published in Science Advances, October 2025. https://doi.org/10.1126/sciadv.adr1524

Wide screen art by Mark Witton

Having large body sizes conferred all sorts of advantages on dinosaurs, but it potentially made breeding a bit complicated. This week we take a look at some weird pathologies in fossil hadrosaurs (duck billed dinosaurs and friends) and what they might tell us about their amourous habits - do broken backs provide evidence of rough housing in the bedroom?

This week's paper is "Deciphering causes and behaviors: A recurrent pattern of tail injuries in hadrosaurid dinosaurs" by Filippo Bertozzo and colleagues, published in IScience November 2025 https://doi.org/10.1016/j.isci.2025.113739

The widescreen artwork is by Troco.