The Fossil Files

Part 2: Around 66 million years ago an enormous asteroid barrelled into the earth and wiped out ichthyosaurs, pterosaurs, and dinosaurs*. Debate has raged back and forth as to whether the dinosaurs were already in decline before this mass extinction or were still going strong. This week, Susie and Rob are joined by Prof. Steve Brusatte to take a look at what vertebrates were doing just before the asteroid hit. In part 2 we discuss what would have happened if the asteroid had missed, Steve's new upcoming book, Jurassic World, and Nannotyrannus.

*except birds of course.

Widescreen artwork by Natalia Jagielska

Around 66 million years ago an enormous asteroid barreled into the earth and wiped out icthyosaurs, pterosaurs, and dinosaurs*. Debate has raged back and forth as to whether the dinosaurs were already in decline before this mass extinction or were still going strong. This week, Susie and Rob are joined by Prof. Steve Brusatte to take a look at what vertebrates were doing just before the asteroid hit. We discuss his new paper on fossil vertebrates from New Mexico, its implications for scenarios of dinosaur evolution and extinction, and what is life is like for a working palaeontologist, digging up Cretaceous fossils.

This week's paper is "Late-surviving New Mexican dinosaurs illuminate high end-Cretaceous diversity and provinciality" by Andrew Flynn, Steve Brusatte and colleagues, published in Science in October 2025. https://doi.org/10.1126/science.adw3282

*except birds of course.

Widescreen artwork by Natalia Jagielska

Artificial Intelligence seems to be changing everything, everywhere, all at once. But how will the science of studying the very old be transformed by the technology of the new? In this episode Susie and Rob take a look at the risks and opportunities for palaeontology with the application of AI: palAIontology. Can we use AI to find, identify, and classify fossils?

The paper's discussed this week are: "Artificial intelligence in paleontology" by Congyu Yu and colleagues published in Earth Science Reviews May 2024 https://doi.org/10.1016/j.earscirev.2024.104765 and "Early humans and the balance of power: Homo habilis as prey" by Marina Vegara-Riquelme and colleagues published in Annals of the New York Academy of Sciences in September 2025 https://doi.org/10.1111/nyas.15321

In the last of our series from the massive Society of Vertebrate Paleontology meeting, Susie and Rob finally manage to catch up for a gossip. In this episode with get a disgusting taste of rotting crocodile experiments with Stephanie Drumheller of the University of Tennessee, an insight into the Dinosaur battle bus education project that has been travelling the Mongolian steppe with Bolor Minjin of the American Museum of Natural History and the Institute for the Study of Mongolian Dinosaurs, and finally how engineering approaches can help us figure out what fossil organisms were up to long after their death with Emily Rayfield, University of Bristol.

New fossil discoveries keep coming thick and fast, but we managed to sit down with the researchers as they present them. In this episode Susie and Rob catch up (in person!) on their second day in Birmingham and talk to the researchers tackling important transitions in vertebrate evolution: the transitions of moving onto land, into the sea, into the air. This includes Emily Hillan of University of Chicago and her discovery of a new specimen of the walking fish (?) Tiktaalik, Dave Hone of Queen Mary University London on his new research on pterosaurs and spinosaurs, Dean Lomax about his new research on ichthyosaurs and his latest book, and Luke Muscutt of Imperial on his swimming plesiosaur robot.

The Fossils Files are on Tour! Susie and Rob are in Birmingham for the massive Society of Vertebrate Paleontology conference which has made a rare trip to Europe. We will be meeting and chatting with palaeontologists from all over the world and bringing you the latest discoveries and hot gossip. On day 1 we join the Nanotyrannus craze and chat to co-author of that study, James Napoli of Stoney Brook NY. The amazing "Duelling Dinos" specimen has been released the world by the North Carolina Museum of Natural Sciences and has sent dinosaur fans aflutter with its implications for tyrannosaurs. We also catch with Yara Haridy of the University of Chicago. She has been revealing lots of new insights into vertebrate origins and evolution with high powered synchrotron analyses. With also catch up Steve Brussatte of the University of Edinburgh as a preview of a longer episode coming up.

For more information on Nanaotyrannus: https://naturalsciences.org/calendar/news/nanotyrannus-confirmed/

And for more information on vertebrate origins, check out our earlier episode "Our deep origins and the vertebrate that wasn't"

A newly discovered fossil from the Cretaceous of Mongolia tells us an interesting story about the purported head butting behaviour of dinosaurs. Pachycephalosaurs are famous for their thick domed heads but it has been disputed how or when this evolved. The beautifully preserved Zavacephale rinpoche has a well preserved skull and dome but also loads of details of the body and tail as well. What is suprising is that this individual is much smaller, and occurs much earlier, than other pachycephalosaurs. We take a look at this new fossil and what this means for interpreting the evolution of dinosaur behaviour.

This week's paper is "A domed pachycephalosaur from the early Cretaceous of Mongolia" by Tsogtbaatar Chinzorig and colleagues from Mongolia and North Carolina, published in Nature in September 2025. https://doi.org/10.1038/s41586-025-09213-6

Wide screen palaeoart by Masaya Hattori.

Cordyceps is a weird fungus that can take over the brain of ants and spiders causing them to go zombie and commit suicide in order to spread disease. Weirder still, some new fossils from the Cretaceous have directly captured this nightmarish behaviour for the first time. We take a look at these interesting fossils, their potentially shady origin story, and their implications for reconstructing evolution of this unsual parasitic behaviour. Side-note: did fungus cause the extinction of dinosaurs?

The main paper discussed this week is by Yuhui Zhuang and colleagues "Cretaceous entomopathogenic fungi illuminate the early evolution of insect–fungal associations" published in Proceedings of the Royal Soceiy B in June 2025, (https://doi.org/10.1098/rspb.2025.0407), free version here.

Discovery of the smallest ever dinosaur acheived quite a splash when it was publised on the front cover of Nature in 2020. The new critter, Oculodentavis, was the size of a hummingbird and reconstructed as close to Archaeopteryx on the lineage to birds. In this episode, Susie and Rob take a look at how this story quickly started to unravel as it turned out Oculodentavis might been something else altogether. This how episode also shed some light on a dark underbelly of an ethical problem for palaeontologists - what if your fossils are coming from a war zone and potentially funding ethic violence?

The main paper discussed this week is by Lida Xing and Jingmai O'Connor and colleagues "Hummingbird-sized dinosaur from the Cretaceous period of Myanmar" published in Nature in 2020, now retracted (https://doi.org/10.1038/s41586-020-2068-4).

A brief accessible summary of what happened afterwards can be found here by Krister Smith in Current Biology "It's a bird, it's a plane, it's Oculudentavis!" (https://doi.org/10.1016/j.cub.2021.06.017).

A summary of the situation with Myanmar amber fossils including discussion of the paper by Emma Dunne and colleagues can be found in Science "Violent conflict in Myanmar linked to boom in fossil amber research, study claims" by Rodrigo Pérez Ortega (doi:10.1126/science.adf0973)

Wide screen palaeoart by Stephanie Abramowicz.

In the first of two episodes on notorious fossil fails, Rob and Susie take a look at how a serious case of mistaken identify unfolded for some Ediacaran 'fossils'. Herein lies a cautionary tail for all relating to pareidolia: our very human tendency to perceive patterns in random shapes and lines, or why we might see jesus is a piece of toast or a smiley face in a cut pepper. This takes us to unexpected destination for hunting for dinosaur fossils: the moon!

Image 1: A look at some 'Ediacaran fossils' from the Bhimbetka cave in India and some other structures found there.

Image 2: "Fossilised embryo of a dinosaur inside the egg on the moon". Yes you read that right.

The main papers discussed this week is by Greg Retallack and colleagues "Dickinsonia discovered in India and late Ediacaran biogeography" published in Gondwana Research in 2021 (https://doi.org/10.1016/j.gr.2020.11.008) with follow up articles by Joseph Meert and colleagues "Stinging News: 'Dickinsonia' discovered in the Upper Vindhyan of India not worth the buzz" published in Gondwana Research in 2023 (https://doi.org/10.1016/j.gr.2023.01.003) and SK Pandey and colleagues "Dickinsonia tenuis reported by Retallack et al. 2021 is not a fossil, instead an impression of an extant 'fallen beehive'" published in 2023 in the Journal of the Geological Society of India (https://doi.org/10.1007/s12594-023-2312-2).

The final paper is by Hari Mohan Saxena and Jagmohan Saxena "Dinosaur eggs with fossilized embryos on the moon" 'published' in the New York Science Journal (http://www.dx.doi.org/10.7537/marsnys160823.030).

Wide screen Ediacaran image by John Sibbeck.