Palaeocast

One of the factors that makes palaeontology such a popular science is its constant ability to surprise us. It seems almost every week that a new study is released that significantly adds to our understanding of ancient life. This could be in relation to a new species, a new analysis or new fossil locality. In this episode, we discuss a new discovery that not only yields a new species, but also provides direct dietary evidence and has us re-evaluating the potential for food to be preserved in coprolites (fossilised droppings).

Joining us for this interview are Drs Martin Qvarnström and Martin Fikáček of Uppsala University and National Sun Yat-sen University, respectively. Both were part of a team that identified and described a new species of beetle preserved within a dinosaur coprolite!

In this first part of the interview, we provide the context for the discovery, discussing the study of coprolites and of beetles. Part 2 of the interview will be released soon.

In this episode, we talk to our very own Dr Elsa Panciroli about her new book Beasts Before Us. In it, she tells the untold story of mammalian evolution, tracing the origin of synapsids back to the Carboniferous. You’ll be taken to fossil sites around the world to meet some of these pioneering animals and some of the palaeontologists that discovered them.

For this interview, we’ll give you an overview of the early evolution of synapsids and dispel many of the misconceptions about what our ancestors were really like.

We’ve got a couple of copies of the book to give away, so look out on our social media channels for details of the competition! For everyone else, Beasts Before Us is available to buy online and in all good book shops.

Crocodiles are often referred to as “living fossils”, but if we compare modern and ancient species, does that label hold up? What different kind of morphologies (shapes) did past crocs have and how did they live? How quickly did this past diversity arise and why are we left with so few species today? What’s to stop them from diversifying again?

In this episode, we speak to Dr Tom Stubbs, University of Bristol, about his recent work analysing changes in crocodylomorph disparity through time. We look at some of the weird and wonderful crocs of the past and work through his methods for calculating their rates of evolutionary innovation. Part 2 of 2

Crocodiles are often referred to as “living fossils”, but if we compare modern and ancient species, does that label hold up? What different kind of morphologies (shapes) did past crocs have and how did they live? How quickly did this past diversity arise and why are we left with so few species today? What’s to stop them from diversifying again?

In this episode, we speak to Dr Tom Stubbs, University of Bristol, about his recent work analysing changes in crocodylomorph disparity through time. We look at some of the weird and wonderful crocs of the past and work through his methods for calculating their rates of evolutionary innovation.

Part 1 of 2

Terrestrial life as we know it couldn’t exist without soil. Soil, as we know it today, is a layer of minerals, organic matter, liquids, gasses and organisms that not only provides a medium for plant growth, but also modifies the atmosphere, provides a habitat for animals and retains and purifies water.

This kind of soil hasn’t always existed, so in order to understand early conditions on land, we first need to understand what can be constituted as a soil and when these first appeared. Is there soil on the Moon? Can soil fossilise?

Since most terrestrial ecosystems are rooted in soil, if we want to understand how life established itself on land, we first need to know how soils form, how they have changed over geological time and which kinds of plants and fungi can live without it.

Joining us in this episode is Dr Ria Mitchell, Experimental Officer in X-ray Computed Tomography at the University of Sheffield, UK.

Part two of our interview with Dr Larisa DeSantis of Vanderbilt University on the 'dietary ecology' of Smilodon.

Smilodon is probably one of the most iconic mammalian apex predators with its extended upper canines and robustly-built forearms. In fact, when we compare Smilodon to modern cats (felids), we don't see these same characteristics. So what were they used for? Was Smilodon specialised for any particular behaviour?

Owing to the unique preservation of the tar seeps at Rancho La Brea, Los Angeles, USA, we can find an overabundance of predators, including Smilodon fatalis, Canis dirus, Panthera atrox and Puma concolor. This allows researchers to reconstruct the predatory landscape of the area in the Pleistocene. Who was eating what? Was there any competition between predators?

Smilodon is probably one of the most iconic mammalian apex predators with its extended upper canines and robustly-built forearms. In fact, when we compare Smilodon to modern cats (felids), we don’t see these same characteristics. So what were they used for? Was Smilodon specialised for any particular behaviour?

Owing to the unique preservation of the tar seeps at Rancho La Brea, Los Angeles, USA, we can find an overabundance of predators, including Smilodon fatalis, Canis dirus, Panthera atrox and Puma concolor. This allows researchers to reconstruct the predatory landscape of the area in the Pleistocene. Who was eating what? Was there any competition between predators?

All of these questions feed in to the ‘dietary ecology’ of Smilodon and here to discuss that, and more, is Dr Larisa DeSantis of Vanderbilt University.

It wouldn’t be outlandish to state that many a fossil collection has started with the acquisition of an ammonite. Their planispiral shells (termed a conch) are instantly recognisable and since that conch was originally composed of the relatively hard mineral aragonite, they better lend themselves to the fossilisation process.

But how much do we actually know about the animal that produces the conch? We might be able to make superficial inferences based on comparisons with the modern Nautilus, but ammonites are actually closer related to squid and octopuses.

So could you recognise an ammonite without its shell?

Prof. Christian Klug of the University of Zurich has recently described just that: a naked ammonite. In this episode, we learn about ammonite soft body anatomy and sink our teeth into the mystery of how this ammonite lost its shell.

The Soom Shale is an Ordovician lagerstätte in the Western Cape of South Africa. Whilst it lacks the diversity of organisms seen in other lagerstätten, such as the Burgess Shale or Chengjiang, it more than makes up for it in the fidelity of preservation.

The taphonomic pathway to the fantastic preservation in the Soom Shale is long and complex, reliant not only on local conditions, but also ties into global climatic events. It’s vitally important when interpreting fossils to understand the taphonomy as it provides so much context as to what you can see in fossils and, as equally important, what you can’t.

Joining us for this episode is Prof. Sarah Gabbott, a taphonomist from the University of Leicester, UK.

Piecing together the early lives of dinosaurs is difficult due to a lack of fossils from juvenile and embryonic stages. In this episode, Elsa Panciroli talks to Dr Kimi Chappelle, a postdoctoral fellow at the Evolutionary Studies Institute, part of the University of Witwatersrand in Johannesburg, South Africa. Chappelle specialises in sauropodomorphs – the precursors of the giant sauropod dinosaurs like Diplodocus. Her recent work is helping build a picture of their growth and development.

Chappelle is a champion of South African palaeontology and nominated as one of the Mail and Guardian’s top 200 young South Africans in Science and Technology. With her colleagues she has published a stunning new study of sauropodomorph embryos from a fossil nest site in South Africa. This new paper visualises and describes their tiny skulls using synchrotron scan data. These fossils provide new information on dinosaur developmental processes, and places South African fossils at the heart of our understanding of their early evolution. Chappelle also talks about the latest work she’s involved with in Zimbabwe, and future research into the growth patterns of the largest dinosaurs to have ever lived.

Lack of diversity is one of the major issues in the sciences in recent times. We’ve discussed diversity in palaeontology in previous podcasts, but in this episode Elsa takes a look at the legacy of racism and colonialism in palaeontology and museum collections, and what efforts are being made to address these issues.

Colonial attitudes towards people of non-European descent have meant that their natural heritage was often plundered and sent back to Europe and the United States to fill museum shelves. Researchers continue to benefit from these resources. How should we change our scientific practice to recognise this legacy and avoid making the same mistakes now and in the future?

In the first part of the episode, Elsa speaks to Christa Kuljian, a historian of science and author of Darwin’s Hunch, based at the University of the Witwatersrand in Johannesburg. She’ll examine the legacy of racism in science, focusing on palaeoanthropology in South Africa, including figures like Robert Broom and Raymond Dart. We’ll hear how attitudes toward different races shaped the research and conclusions of past generations of scientists.

In the second part, Rob Theodore, Exhibitions and Displays Coodinator at the Sedgewick Museum in England, talks about the legacy of colonialism in museum collections. We’ll find out about the ways in which specimens were collected in the past, and how this was related to contemporary events and attitudes. We’ll also find out what moves being taken to decolonise museums and refocus public outreach to recognise the past and move positively into the future.

When we think about the Ice Age or the Pleistocene, we generally think of large animals: wooly mammoths trudging through snow, sabre-tooth tigers taking down their next meal, and big bison out on the steppes. These are really interesting things to think about, but what else can we learn from the Pleistocene other big animals and their extinction?

We can also use the Pleistocene (which is relatively similar to the modern world in terms of continental layout, landscapes, and ecological niche availability) to explore questions of palaeoecology, biotic interactions and how changes in the environment can affect the local fauna. The relatively young age of the Pleistocene means that the available data is very different to palaeoecological studies of the Cretaceous or Eocene. This means that it is more appropriate for drawing comparisons to what's happening today or what might happen in the future with climate change.

Joining us in this interview is Dr Jacquelyn Gill, an Associate Professor at the University of Maine, who works in palaeoecology. We talk about the different data available, the importance of understanding palaeoecology, including a recent paper from her group on seabird ecology in the Falklands, and what this might mean for the future.

Part 2.

Diatoms are a major group of algae found in waters all around the world. As photosynthetic phytoplankton, they are hugely important ‘primary producers’, integral to nearly every aquatic food chain. They are responsible for a large proportion of the world’s oxygen production, with estimates ranging between 20 and 50%.

Diatoms are unicellular plants that produce their cell walls, termed frustules, out of silica. These intricate frustules are what we find preserved in the fossil record and they can contain an absolute wealth of information.

In this interview, Prof. Anson Mackay, University College London, joins to discuss his work on the diatoms from Lake Baikal, Siberia. We learn why lakes are such special ecosystems and what diatoms can tell us about the world through studies of their palaeoproductivity over thousands of years.

Diatoms are a major group of algae found in waters all around the world. As photosynthetic phytoplankton, they are hugely important ‘primary producers’, integral to nearly every aquatic food chain. They are responsible for a large proportion of the world’s oxygen production, with estimates ranging between 20 and 50%.

Diatoms are unicellular plants that produce their cell walls, termed frustules, out of silica. These intricate frustules are what we find preserved in the fossil record and they can contain an absolute wealth of information.

In this interview, Prof. Anson Mackay, University College London, joins to discuss his work on the diatoms from Lake Baikal, Siberia. We learn why lakes are such special ecosystems and what diatoms can tell us about the world through studies of their palaeoproductivity over thousands of years.

Part 2 of 2.

The horseshoe crabs (Xiphosura) are a group of large aquatic arthropods known from the East coast of the USA, and the Southern and Eastern coasts of Asia. Despite their name, they are not actually crabs at all, but are chelicerates (the group containing spiders and scorpions). As a group, the horseshoe crabs possess an extremely long fossil record, reaching as far back as the Ordovician Period, some 480 million years ago. Since that time, they would appear to have undergone very little change, leading the horseshoe crabs to become the archetypal ‘living fossils’.

Joining us for this two-part episode is Dr Russell Bicknell, University of New England, Australia. We discuss what makes a horseshoe crab, before taking questions from our listeners as to all aspects of horseshoe crab ecology and what we can infer from them about other extinct arthropods.

The horseshoe crabs (Xiphosura) are a group of large aquatic arthropods known from the East coast of the USA, and the Southern and Eastern coasts of Asia. Despite their name, they are not actually crabs at all, but are chelicerates (the group containing spiders and scorpions). As a group, the horseshoe crabs possess an extremely long fossil record, reaching as far back as the Ordovician Period, some 480 million years ago. Since that time, they would appear to have undergone very little change, leading the horseshoe crabs to become the archetypal 'living fossils'.

Joining us for this two-part episode is Dr Russell Bicknell, University of New England, Australia. We discuss what makes a horseshoe crab, before taking questions from our listeners as to all aspects of horseshoe crab ecology and what we can infer from them about other extinct arthropods.

With palaeontology as popular as it is you will never be short of content online, whether that be articles, blogs, podcasts (of which there are now many others you should also be listening to) or videos. This allows you, the public, to enjoy learning about past life on demand and in a format that best suits you. The only issue with having so many sources of information/entertainment is that the quality can be highly variable and it can be difficult to determine whether any given outlet/channel values more the accurate communication of palaeontological science or the number of viewers/ad revenue they get.

Amongst some notable exceptions to this issue is the YouTube channel PBS Eons, who have produced a hugely successful series that also stands up to scientific scrutiny. In this interview, we're joined by Eons host Kallie Moore who discusses everything to do with the show, from how it is researched and shot, to the benefits of using YouTube for outreach.

The end-Cretaceous (or K-Pg) extinction is one of the best known mass extinctions in Earth's history, primarily because that is when non-avian dinosaurs disappeared. Although the popular idea is that an asteroid impact was what caused the extinction, the science hasn't actually been that clear. More recently, a second hypothesis has challenged the idea asteroid as the main culprit, suggesting that huge volcanic eruptions in what is now India called the Deccan Traps was responsible. It has also been suggested that dinosaurs were already in decline when these things happened, speeding up the inevitable.

In this interview, we speak with Dr Alessandro Chiarenza, a research associate at University College London about his new paper published today in PNAS showing that it really was the asteroid impact that killed the dinosaurs. This new study, based on research he did during his PhD at Imperial College London, uses a large amount of data put into climatic models to analyse different scenarios caused by an asteroid impact, the Deccan Traps volcanism, and a combination of the two. This study showed that the asteroid caused a prolonged impact winter, causing the extinction of the dinosaurs.

In this episode, in conjunction with the Society of Vertebrate Paleontology (SVP), we investigate issues of diversity in palaeontology, through interviews with Jann Nassif (PhD student at Ohio University, USA) on being transgender in palaeontology; Professor Taissa Rodrigues (Universidade Federal do Espírito Santo, Brazil) and Dr Femke Holwerda (Dr Betsy Nicholls Postdoctoral Research Fellow at the Royal Tyrrell Museum of Palaeontology, Canada) about women in palaeontology; and Gabriel-Philip Santos (Collections Manager and Outreach Coordinator at the Raymond M. Alf Museum of Paleontology at The Webb Schools) about racial diversity. We also spoke with Professor Jessica Theodor (University of Calgary), the Vice President of SVP about what they are doing to increase diversity and address these issues. This episode was recorded in 2019 at the SVP meeting in Brisbane, Australia, but for several reasons has taken us a little while to complete. Given the current discussions and anti-racism activism going on around the world, we thought this was a good time to reflect on some of the issues within our science and the ways in which they are being addressed.

One of the great themes in palaeobiology is the water-land transition, or how and when the ancestors of today’s four-legged terrestrial animals moved to land. Lines of questioning have included understanding the anatomy and biomechanics of the axial skeleton- head and vertebrae (focusing on biting and swallowing) and the appendicular skeleton (focusing on how the earliest tetrapods walked or swam). Our picture of this story has drastically changed in the last three decades, as new fossils have filled in crucial gaps in the tetrapod evolutionary tree. This changing picture really came to the fore with the work of the late Professor Jenny clack, who’s work at Cambridge in early tetrapods from Greenland and elsewhere  brought the water land question back in fashion. 

Joining us to discuss Jenny Clack's Legacy in this episode are Prof. Mike Coates and Ben Otoo both of the University of Chicago.