Scleromochlus is an animal that has been known for over 100 years, and has been frequently suggested as being an ancestor to pterosaurs. It hails from the Late Triassic of Scotland, and there are fewer than 10 specimens known. Unfortunately the preservation of this small reptile means that it is very difficult to interpret. However, thanks to the wonders of modern technology and CT scanning, new evidence from Scleromochlus reveals new anatomical insights, and further supports Scleromochlus as a lagerpetid, the group most closely related to pterosaurs.

In this episode we discuss these new discoveries with the lead author of the study Dr Davide Foffa who is currently a postdoctoral fellow at Virginia Tech, though this work was part of his previous position at the National Museum of Scotland (NMS). This is part of a larger project looking at the Late Triassic 'Elgin Fauna' along with collaborators Richard Butler (University of Birmingham), Stig Walsh and Nick Fraser (NMS), Steve Brusatte (University of Edinburgh) and Paul Barrett (Natural History Museum, London).

This year marks the 175th anniversary of The Palaeontographical Society. Having been established in 1847, PalSoc is the world’s oldest Society devoted specifically to the advancement of palaeontological knowledge in existence. The primary role of Pal Soc is to promote the description and illustration of British fossils, which it does through monographs.

In the first part of this two-part episode, we speak to Dr Victor Monin a historian of science who specialises in the history of palaeontology, especially palaeoart. How did PalSoc influence how fossils were visually represented in scientific literature?

Bolca is a site of exceptional preservation of fossils (termed a konservat lagerstätte) located close to Verona, Italy. This 50 million year old limestone was deposited in the Eocene Epoch and contains over 500 species of plants, arthropods terrestrial vertebrates and most notably a lot of fish! The preservation at Bolca is so detailed that even the external colouration of the skin and internal anatomy of many of these fossils can be seen.

Exploring the taphonomy (the processes that occur to a body between death and discovery) and palaeoecology (how fossil organisms lived and interacted with other organisms and their surroundings) of some of the fish from Bolca is Dr Valentina Rossi from University College Cork, Ireland. In this episode, we look at how colour patterns are preserved in a fossil moonfish and look at what that can tell us about how the species lived.

In the last few years there has been lots of new work on the iconic Spinosaurus - was it aquatic? What about its relatives? What kind of evidence can we look at to tell us this answer? In this episode we speak with Dr. Matteo Fabbri, from the Field Museum of Chicago, who has been working on Spinosaurus and other relatives and has recently published a detailed study supporting the idea that some spinosaurids were likely a swimming, aquatic dinosaur at least part of the time. He walks us through the evidence for spinosaurids being semi-aquatic and tells us why they think they could swim.

Marrellomorphs are the group of early Paleozoic arthropods that get their name from the well-known Burgess Shale fossil Marrella splendens. They have for a long time been considered to be closely related to the trilobites, based on similarities in their gills, but numerous studies have since suggested they are closer related to mandibulate arthropods (crustaceans, insects & myriapods), although their strange appearance means other relationships might still be plausible.

Since they have a soft exoskeleton, marellomorphs have a very poor fossil record and so the discovery of any new specimens outside of the Burgess Shale can be incredibly significant. In this interview, we speak to Joe Moysiuk of the University of Toronto and Royal Ontario Museum about his newly described species Tomlinsonus dimitrii.

Sloths (or do you pronounce it “sloths”?), are a group of tree-dwelling xenarthrans from South and Central America. They are well known for their sedentary lifestyles where they just hang around and seemingly do fairly little. But has this always been the case? When we look back at the fossil record of sloths, what kinds of ecologies do we see? How far back does their fossil record actually go?

In this episode, we speak to Dr Robert McAfee (Philadelphia College of Osteopathic Medicine) about his research looking into the fossil record of sloths in all of its “beautiful absurdity”. His work has been focussed on the island of Hispaniola (Haiti and the Dominican Republic) and the remarkably rich cave deposits found there.

The end-Cretaceous mass extinction was a cataclysmic asteroid impact that ushered in the end of the non-avian dinosaurs and forever changed the course of evolution on Earth. But what can we say about the timing of the event, other than it happened 66 million years ago?

Well, it turns out that Tanis, a relatively-recently discovered fossil site in North Dakota, is full of lines of evidence that are allowing earth scientists to piece together when the impact occurred.

In this episode, we’re joined by Melanie During, Uppsala University, who has been examining the details of the bones of fish to say more about the world either side of the event.