Palaeocast

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.

Perhaps one of the most overlooked areas of palaeontology, within the public eye, is micropalaeontology. Micropalaeontology is an umbrella discipline, covering a diverse range of organisms, with representatives from many of the highest level biological groupings. Although small in size, microfossils prove invaluable for research into palaeoclimatology and are also one of the most commercially applicable groups of fossils.

In this interview we speak to Dr. Giles Miller, Senior Curator of Micropalaeontology at the Natural History Museum (NHM). As each individual group of microfossils could warrant an entire series, this episode serves as an introduction to micropalaeontology. We discuss what it is and some of its applications, all within the context of how the micropalaeontology collection at the NHM is used.

Ichnology is the study of trace fossils (also termed ichnofossils). Opposed to body fossils, the physical remains of an organism, trace fossils are the fossilised interactions between an organism and the substrate/sediment and include such things as trackways, excrement, burrows, bite marks and borings. Both body fossils and trace fossils are important when studying an organism and especially so in determining palaeoecology (how an organism interacted with its immediate environment). Body fossils can only inform us of the anatomy of the dead organism and its physical constraints, from which we can infer modes of life. Trace fossils, on the other hand, record the activity of organisms in life; it can be possible to see evidence of how certain communities functioned, or how an organism interacted with its environment. However one drawback is that the producer of a trace fossil is not always known, or we can't be certain that any one organism produced a specific trace.

In the second part of this two-part episode, we speak to Prof. Anthony Martin from Emory Euniversity, USA, archosaur burrows, the feasibility of dinosaurs over-wintering on the South Pole and Paleo-Barbie.

Ichnology is the study of trace fossils (also termed ichnofossils). Opposed to body fossils, the physical remains of an organism, trace fossils are the fossilised interactions between an organism and the substrate/sediment and include such things as trackways, excrement, burrows, bite marks and borings. Both body fossils and trace fossils are important when studying an organism and especially so in determining palaeoecology (how an organism interacted with its immediate environment). Body fossils can only inform us of the anatomy of the dead organism and its physical constraints, from which we can infer modes of life. Trace fossils, on the other hand, record the activity of organisms in life; it can be possible to see evidence of how certain communities functioned, or how an organism interacted with its environment. However one draw back is that the producer of a trace fossil is not always known, or we can't be certain that any one organism produced a specific trace.

In this first of a two-part episode, we speak to Prof. Anthony Martin from Emory Euniversity, USA, all about trace fossils, why they are important and how they can be used.

Every palaeontologist needs to put their feet up once in a while, and what better place to do so that the Best Western Denver Southwest? This hotel is located just a stone's-throw away from Dinosaur Ridge, one of the world's most famous fossil sites. It was here that many of the house-hold dinosaur names such as Apatosaurus (formerly Brontosaurus) and Stegosaurus were first discovered during the 'Bone Wars' between Edward Drinker Cope and Othniel Charles Marsh in the late 19th century. The hotel is currently being re-branded, by science-advocate owners Greg and Meredith Tally, as a celebration of the rich paleontological history of the local area, both recent and ancient. Museum displays, fossil replicas and even a swimming pool shaped like the Western Interior Seaway are all planned, not only to excite the inner-child in each of us, but also to educate. We managed to catch up with Greg and Meredith, on a break from the construction, to talk all about their designs and the inspiration behind their re-branding, a story that strangely begins with Physicist Nicolai Tesla and a cartoon on theoatmeal.com.

Fossils, at the best of times, are difficult to interpret. Palaeontologists attempt to reconstruct organisms from what little remains are left. This can be relatively simple for groups that we are familiar with today; you can easily make comparisons between a fossil lobster and a living one. But how do you interpret a fossil that has no modern counterpart and is not clearly related to any other organism? We speak to Dr Jakob Vinther of the University of Bristol about his experience of interpreting some of the oldest and most cryptic specimens in the fossil record. We look at molluscs, worms, worm-like molluscs and mollusc-like worms.

Sexual selection is responsible for much of the astounding diversity in morphology and behaviour that we can see in animals and plants today, but how can we reliably recognise it in the fossil record? We speak to Dr. Rob Knell of Queen Mary University of London.

The first animals came onto land sometime before 425 Ma. These early colonizers were members of a group called the arthropods - probably early relatives of the millipedes first. However, early land animals - especially those from the Palaeozoic era (542 - 252 Ma) - are relatively rarely preserved as fossils. The Carboniferous period (350-299 Ma) is an exception to this rule. During the Late Carboniferous, there is a window in which land animals are found preserved within the iron carbonate mineral siderite. This kind of preservation allows palaeontologists to use 3D reconstruction techniques - such as high resolution CT scanning - to investigate this unique insight into early land-based ecosystems. We talk to Dr. Russell Garwood - an 1851 research fellow at the University of Manchester - about the Carboniferous, the land animals which were around at the time, and the techniques he uses to study these.

The 16th to the 18th December 2012 saw University College Dublin host The Palaeontological Association (PalAss) 56th annual general meeting. Palaeocast were present at the conference for quite a few reasons: firstly, it's always good to try and keep on top of the latest research in the field and conferences are the places to be for hearing a lot of ideas, covering a diverse array of topics, in a short period of time; secondly, we wanted to promote ourselves to the delegate in the hope of securing further interviews for the coming year; and thirdly, we wanted to drum up support for our 'Palaeo101' initiative which should finally be taking off this year.

The Mesozoic Era saw the spectacular rise and fall of many groups, particularly in terrestrial vertebrates. These include birds, squamates, crocodiles, and pterosaurs, who wove a complex tapestry of evolution through the 185 million years of the Mesozoic, some even persisting until now. Dave Hone, now of Queen Mary in London, has extensively studied the ecology of many of these now-extinct organisms, especially theropod dinosaurs, to gain rare insights into how they would have lived millions of years ago. You can keep track of his research by following his blogs at the Guardian and Archosaur Musings webpages.