400 million years ago, before the rise of forests, the land was covered in mossy carpets, loomed over by weird 8 meter tall columns called Prototaxites. These weird giants have long been thought to be some sort of fungus body, slowly digesting rotting matter. A new paper has taken a detailed look at some well preserved fossils from the Devonian of Scotland and reveals that this enigmatic giant wasn't a fungus, wasn't a plant, wasn't an animal, and wasn't a bacterium... it was something else. This week Susie and Rob take a look at the strange world of the Devonian giant Prototaxites and speculate what it might, or might not, have been. In other fungus news, we also take a look at a paper using fungal microfossils to suggests that dinosaur extinction could have been a multi-phase event, before and after the asteroid impact at the end of the Cretaceous.

The main paper discussed this week is "Prototaxites fossils are structurally and chemically distinct from extinct and extant Fungi" by Corentin Loron and colleagues from the University of Edinburgh, published in Science Advances in January 2026 https://doi.org/10.1126/sciadv.aec6277

The other paper is "Fungal proliferation before and after the Cretaceous–Paleogene mass extinction event in North America" by Rosanna Baker and colleagues published in PNAS in May 2026 Fungal proliferation before and after the Cretaceous–Paleogene mass extinction event in North America https://doi.org/10.1073/pnas.2536899123

Wide screen art by M Humpage

Cretaceous oceans have long been accepted as a dangerous place full of massive mosaurs and other predators. Now some new fossils from Japan have upended this with the suggestion that the "top dog" was not any vertebrate, but instead giant octopuses that were far larger than any invertebrates alive today. This has generated a lot of Kraken related headlines (and social media posts), but is everything as it seems? This week Susie and Rob take a look at these claims and ask: were super intelligent giganto-octopuses the top predators in Cretaceous? Get your salt shaker to hand, because you mind need to take it with a pinch of salt.

This weeks paper is "Earliest octopuses were giant top predators in Cretaceous oceans" by Shin Ikegami and colleagues published in Science in April 2026 https://doi.org/10.1126/science.aea6285

Another paper mentioned is "Synchrotron data reveal nautiloid characters in Pohlsepia mazonensis, refuting a Palaeozoic origin for octobrachians" by Thomas Clements and colleagues, published in Proceedings of the Royal Society B in April 2026 https://doi.org/10.1098/rspb.2025.2369

Widescreen art by HodariNundu

Are we alone? For decades a global effort has been made to search for extraterrestrial intelligence (SETI), but have we been looking in the wrong place? A new paper suggests that we should be looking for advanced technological civilizations that had access to coal as this was an important energy rich source enabling industrialisation. In this bonus episode, Susie and Rob take a look at the geological, palaeontolological and evolutionary implications of the seach for coal burning aliens.

This week's paper is "How common are oxygenic photosynthesis and large coal deposits on exoplanets?" by Lincoln Taiz and colleagues, published in the International Journal of Astrobiology in January 2026.

Widescreen art by NASA/SETI.

Smell defines so much of animal's life from finding a mate, to tracking down food sources and avoiding predators. Genetics and behaviour can offer us rich insights for modern organisms, but what about extinct organisms? How did they smell and what was their ecology? This week we take an interesting paper that has found evolutionary links between the endocasts of mammal brains and genetic markers for their 'smellability'. The authors explore how we can use this relationship to infer the smelling habits of sabre toothed cats and giant armadillos, and to reconstruct the evolutionary origins of whales. Get sniffing!

This week's paper is "The olfactory bulb endocast as a proxy for mammalian olfaction" by Quentin Martnez and colleagues published in PNAS in December 2025 https://www.pnas.org/doi/10.1073/pnas.2510575122 We also briefing mention another paper about Cambrian critters in the Ediacaran by Li et al https://www.science.org/doi/10.1126/science.adu2291

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://www.patreon.com/c/FossilFiles