Palaeocast1 Touko 2013

Episode 16: Multicellularity in cyanobacteria

One of the most significant events in Earth’s history has been the oxygenation of its atmosphere 2.45–2.32 billion years ago. This accumulation of molecular oxygen in Earth’s atmosphere was so significant that it is now commonly known as the Great Oxidation Event (GOE). The long-reaching effects of the GOE were literally world-changing; the compositions of the atmosphere and hydrosphere were altered, and through various redox reactions (where atoms have their oxidation state changed), the nature of the continents and global climate changed too. However, and perhaps from an anthropocentric viewpoint, the most important effect would be upon the biosphere: the GOE paved the way for the evolution of aerobic (oxygen respiring) organisms, including our earliest ancestors.

It is possible to track the GOE through geochemical traces left in the rock record. However, one thing we're still uncertain about is whether or not this event represents either a sharp increase in oxygen production or a reduction in oxygen sinks - the jury is still out on that one. With this level of ambiguity over the dynamics of the GOE, it may be a little surprising to know that there has been a long-standing consensus on how the oxygen was actually produced: photosynthetic organisms called cyanobacteria (blue-green algae, so named after the pigment they produce).

In this episode we discuss with Dr. Bettina Schirrmeister (University of Bristol) about the evolution of cyanobacteria and the role they played in the GOE.

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Episode 176: Insect Gigantism Pt2

The Carboniferous period is host to some of the largest arthropods to have ever lived. Giant taxa such as the griffenfly Meganuera and the millipede Arthropleura are almost talismanic and are often de...

13 Touko 48min

Episode 175: Insect Gigantism Pt1

2 Touko 39min

Episode 174: A History of Dinosaurs in 50 Fossils

Prof. Paul Barrett of the Natural History Museum, London, recently authored A History of Dinosaurs in 50 Fossils. We took this as an opportunity to get an overview of what we really know about dinosau...

15 Huhti 58min

Episode 173: Petrified Forest

Petrified Forest National Park in northeastern Arizona, USA is a hub for Triassic palaeontology and has exposures representing 20 million years of the Late Triassic Chinle Formation. Visitors marvel a...

17 Maalis 49min

Episode 172: Rhynchocephalians

Today, there is only one living species of rhynchocephalian: the tuatara of Aotearoa/New Zealand. Despite today's paucity of species, this was once a diverse group of reptiles, with a wide range of li...

5 Helmi 52min

Episode 171: Freshwater Mosasaurs

We've been given exclusive access to a brand new study examining the chemistry of a mosasaur tooth found within the Late Cretaceous Hell Creek Formation, North Dakota. The remarkable circumstances of ...

12 Joulu 20251h 34min

SVP 2025

3 Joulu 202557min

Episode 170: Cariocecus bocagei

The iguanodontians were an incredibly successful group within the Cretaceous. They could reach incredible sizes, with the largest species even matching the proportions of some sauropods, and they also...

19 Syys 20251h 50min