The Fossil Files

The Fossil Files needs YOU to tell us what you think! Please take 5 minutes to fill out the survey here 
https://www.qualtrics.manchester.ac.uk/jfe/form/SV_8J77u7ENVOaDPNk
For this week's episode, we dive into a baffling array of interweaving palaeo-controversies. Where should scientifically important fossils be homed in this globalised and commercialised world? Who gets access to fossils if we need to check on someone else's potentially mistaken interpretations? Susie and Rob take a look at the fascinating story of a new filter-feeding pterosaur called Bakiribu found inside a fossilised vomit from the Cretaceous of Brazil. But was it actually a pterosaur? Another team on the other side of the world came to the conclusion that it might in fact be a fish. Who is right and how to we sort this out? What does this tell us about palaeontology, colonialism, and reproducibility? How does a holotype specimen end up for sale on the private market? And do we have a new edition to add to our pantheon of infamous "Fossil Fails"? 
The papers discussed this week are "A regurgitalite reveals a new filter-feeding pterosaur from the Santana Group" by RV Pêgas and colleagues published in Scientific Reports in November 2025 https://doi.org/10.1038/s41598-025-22983-3
And "Reinterpretation of Bakiribu waridza from the Romualdo Formation (Lower Cretaceous) of Brazil: a fish not a pterosaur" by David Unwin and colleagues published in Anais da Academia Brasileira de Ciências in April 2026 https://doi.org/10.1590/0001-3765202620251374
With the associated editorial "Scientific errors in paleontology - the case of Bakiribu: pterosaur or fish?" by Alexander Kellner https://doi.org/10.1590/0001-3765202620269802
We also get into the issue of illegal export of Brazilian fossils including the controversial case of the fossil 'snake' Tetrapodophis
https://www.estadao.com.br/ciencia/herton-escobar/author-of-4-legged-snake-paper-defies-brazilian-fossil-laws/
As well as the baffling circumstances that led to a fossil holotype of a dinosaur in the collections of a famous Paris museum to be put up for sale https://www.nationalgeographic.com/newsletters/article/stones-bones-french-auction-dubreuillosaurus
You can support at our Patreon where you can get access to exclusive bonus content https://www.patreon.com/cw/FossilFiles
Wide Screen art by Julio Lacerda.

Were dinosaurs to big to walk? In last episode we looked at some of the science of whether large dinosaurs such as sauropods could cross oceans. This week we look at some of the perhaps… less scientific approaches to dinosaurs swimming; The Aquatic Dinosaur hypothesis contends that dinosaurs would have been too big to walk on land and must have been swimmers. We poor some scorn on this with the help of Dr Darren Naish. We also take a look at some palaeo-drama over interpretations of skin colour in sauropods using fossil melanosomes (i.e. tiny subcellular organelles that contain pigments).
The papers discussed this week are "The response to and rejection of Brian Ford's Too Big to Walk, a 21st century effort to reinstate the aquatic dinosaur hypothesis" by Darren Naish published June 2024 in Historical Biology  https://doi.org/10.1080/08912963.2024.2421268
And for the sauropod colour "Fossilized melanosomes reveal colour patterning of a sauropod dinosaur" by Tess Gallagher and colleagues published in Royal Society Open Science December 2025 https://doi.org/10.1098/rsos.251232 and the response paper by Valentina Rossi and Maria McNamara "The colour of sauropod skin. A comment on: 'Fossilized melanosomes reveal colour patterning of a sauropod dinosaur', (2025) by Gallagher et al." published in September 2026 https://doi.org/10.1098/rsos.260429
And for those that are really interested, the paper that we didn't have time to get into can be found here https://doi.org/10.1038/srep21138
Wide screen art by Sante Mazzei

This is a preview of a bonus episode. Full bonus episodes are available to our Patreon members via https://www.patreon.com/cw/FossilFiles
 
Scientists have a responsibility to get their research into the wider world via the media and the press. This is especially true to palaeontologists as we have fortune of working in a field that sparks the imagination of the wider public. But how is this done? In this bonus episode we take a look at the process of how palaeontologists get their work out there, and the relative responsibilities of scientists, press officers and journalists. Along the way we take a look at some remarkable failures of public communication of science and try to learn lessons from them.
Some of the news stories we discuss, including the Metro, Daily Mail, and The Telegraph,are linked below
https://metro.co.uk/2017/10/11/this-strange-walrus-lizard-dog-pig-may-hold-the-key-to-saving-us-all-scientists-claim-6992095/amp/
https://www.dailymail.com/sciencetech/article-2589969/The-520-million-year-old-gentle-giant-Fossil-reveals-bizarre-new-species-whale-ancestor-filtered-plankton.html
https://www.telegraph.co.uk/science/2016/04/24/dino-brexit-bizarre-migration-saw-dinosaurs-flood-out-of-europe/
https://bsky.app/profile/newscientist.com/post/3mi4i4jeuwk2i
We also took a look at the reporting of this paper from 2009 about the fossil primate Darwinius
https://doi.org/10.1371/journal.pone.0005723
Wide screen art includes palaeoart of Kongonaphon by Frank Ippolito

Dinosaurs were massive. No cap. They spread all over the world, but how did they cross oceans? In this episode we ask the question: how far could a dinosaur swim? This isn't just an esoteric question, but one that has a big impact on how we try to reconstruct palaeobiogeography of the Mesozoic and how diversification happens. To do so we look at some new fossil finds from Spain and some weird maths based on rare footage of ostriches swimming and how much fat was on a sauropod. 
This week's papers are 
"Intercontinental evidence of the iconic genus Diplodocus Marsh, 1878 (Dinosauria, Sauropoda)" by Sergio Sánchez-Fenollosa and colleagues published in Journal of Vertebrate Paleontology in Jan 2026 http://dx.doi.org/10.1080/02724634.2026.2718423 and 
"ENHYDROSS: A New Mechanistic Model Supports the Trans-Oceanic Dispersal Capability of Terrestrial Vertebrates" by Alexandros Pantelides and colleagues published in Ecology and Evolution in March 2026 https://doi.org/10.1002/ece3.73280 
Wide screen art by Sante Mazzei

How and when did mammals transition from laying eggs to live birth? The fossil record doesn't typically preserve soft tissues like embryos and placentas making this a tough problem. This week we take a look at two new fossil discoveries that begin to answer the question of mammal evolution, and challenge orthodoxy. A cute baby dicynodont fossil from the Triassic of South Africa is the first mammal to be captured 'in ovo' i.e. inside its egg. Secondly, we discuss a new fossil cynodont from the Triassic of Argentina that might have recorded its growth and birth in its bone histology. Using this we begin to piece together our own evolutionary history and estimate when placental mammals 'got cracking'. Along we way we ask if viviparity evolved twice and whether teenagers can be trusted to go to the shops to get eggs.
The papers discussed this week are "The first non-mammalian synapsid embryo from the Triassic of South Africa" by Julien Benoit and colleagues published in PLoS One in April 2026 https://doi.org/10.1371/journal.pone.0345016 and "Early origin of viviparity in the mammalian lineage" by Leandro Carlos Gaetano and colleagues published in Frontiers in Mammal Science https://doi.org/10.3389/fmamm.2026.1845319
Palaeoart by Sophie Vrard.