Palaeocast

Ostracods are tiny crustaceans (relatives of shrimps, crabs and water-fleas), distinguished by having a shell that is easily fossilised. As microfossils, by virtue of a long and rich fossil record, ostracods are extremely useful for determining the age of the sedimentary strata in which they are found, as well as providing clues to the nature of the environments and climates in which those deposits were formed. The first ostracods lived in shallow continental shelf seas during the early Ordovician period nearly 500 million years ago, later spreading and diversifying into deep oceanic as well as continental environments such as lakes and rivers.  Today, as living organisms, they are globally widespread and diverse, inhabiting almost every kind of aquatic environment from the abyssal depths of the oceans to freshwater ponds.

Welcome to the final day of our coverage of the 4th International Palaeontological Congress (IPC4) from Mendoza, Argentina. 

Welcome to the third day of our coverage of the 4th International Palaeontological Congress (IPC4) from Mendoza, Argentina. 

Welcome to the second day of our coverage of the 4th International Palaeontological Congress (IPC4) from Mendoza, Argentina. 

Welcome to our coverage of the 4th International Palaeontological Congress (IPC4) from Mendoza, Argentina. The International Palaeontological Congress is a global meeting devoted to Palaeontology throughout the world. It convenes every four years under the aegis of the International Palaeontological Association. Following tree previous editions in Sydney (2002), Beijing (2006) and London (2010), it now comes to the American continent for the first time. This conference is one of the most important events on any palaeontologist's calendar and so draws in delegates from all corners of the globe. Over the next few days we're going to have a fantastic opportunity to hear about the latest research in the field with more of a focus on the Southern Hemisphere. 

Planktonic foraminifera are single celled organisms that are highly abundant in modern oceans and a hugely important part of the Earth’s carbon cycle. Each cell builds a hard calcite ‘test’ around itself in a huge variety of shapes. These tests continuously rain down on to the ocean floor leaving continuous records of how these organisms have changed over millions of years. They form the most complete fossil record we have, and are a very useful tool in everything from the oil industry to understanding how evolution works.

Planktonic foraminifera are single celled organisms that are highly abundant in modern oceans and a hugely important part of the Earth's carbon cycle. Each cell builds a hard calcite 'test' around itself in a huge variety of shapes. These tests continuously rain down on to the ocean floor leaving continuous records of how these organisms have changed over millions of years. They form the most complete fossil record we have, and are a very useful tool in everything from the oil industry to understanding how evolution works. In this episode we talk to Dr Tracy Aze from the University of Leeds about her research using planktonic forams to understand macroevolutionary change, as well as decoding their record to map major climate events and temperatures throughout geological history.

We now find ourselves embarking upon our third year, but before we do so, we're going to take a look back at last year and see what we've all been up to.

We’re all familiar with canines (dogs, wolves, jackals, foxes, etc), but these are just only one of three sub-families of the larger canid family to survive to the present day. There were also the Hesperocyoninae and Borophaginae, but what did these other canids look like and why did they go extinct? The canid family also falls within the larger suborder Caniformia which includes skunks, bears and seals, but how are all these related?

We're all familiar with canines (dogs, wolves, jackals, foxs, etc), but these are just only one of three sub-families of the larger canid family to survive to the present day. There were also the Hesperocyoninae and Borophaginae, but what did these other canids look like and why did they go extinct? The canid family also falls within the larger suborder Caniformia which includes skunks, bears and seals, but how are all these related? We've therefore quite a lot of history of the group to cover before we eventually see Canis lupus familiaris become man's best friend. To talk us through their evolution is Dr Xiaoming Wang of the Natural History Museum, Los Angeles.

Anomalocaridids are iconic Cambrian animals, originally found in the Burgess Shale deposits in Canada. From the Genus Anomalocaris, their name translates as 'strange shrimp' owing to their initial misidentification from incomplete remains. In fact, it took until 1985 to realise that three different animals were all actually disarticulated parts of the same animal! Our knowledge of these enigmatic creatures has increased exponentially in recent years owing to many exciting new fossil discoveries, as well as reanalysis of old specimens using new technologies. Researchers are  building up a picture of a group of animals  far more diverse than previously expected, including apex predators as well as possible filter feeders and scavengers. Their temporal range is surprising too - they survived the end Cambrian extinctions when many other taxa died out, and many questions about their ecology, relationships and extinction remain to be answered.

The celebrate the launch of 'The Paleoart of Julius Csotonyi' from Titan Books we take a look at the field of palaeoart. In this episode, we're joined by Julius himself and ask how his images are produced, why they're produced and to discuss the value of palaeoart. We also run our first competition, please follow using #palaeocastart  

One of the longest-ranging and outwardly primitive-looking groups of animals on the planet are the Medusozoa. In consisting of around 95% water, it may be surprising to know that there is a fossil record of jellyfish, however how does one differentiate their fossils from other abiotic sedimentary structures when both look like sub-spherical blobs?   In this episode we speak to Graham Young, Curator of Geology and Paleontology at The Manitoba Museum, Canada, who addressed the identification of jellyfish fossils in a recent paper Young & Hagadorn 2010 The fossil record of cnidarian medusae.

One of the longest-ranging and outwardly primitive-looking groups of animals on the planet are the Medusozoa. In consisting of around 95% water, it may be surprising to know that there is a fossil record of jellyfish, however how does one differentiate their fossils from other abiotic sedimentary structures when both look like sub-spherical blobs? In this episode we speak to Graham Young, Curator of Geology and Paleontology at The Manitoba Museum, Canada, who addressed the identification of jellyfish fossils in a recent paper Young & Hagadorn 2010 The fossil record of cnidarian medusae.

Echinoderms are characterised by a mineralised skeleton, specialised water vascular system and five-fold symmetry. It is this unusual body plane symmetry that gives the starfish its star-shape. None of these features, however, are possessed by the closest living relatives of echinoderms – the hemichordates. Palaeontology offers a unique perspective into the early evolution of echinoderms, revealing that echinoderm characteristics were acquired in a step-wise fashion from a bilaterally symmetrical ancestor. We speak to Dr Imran Rahman, a postdoctoral researcher at the University of Bristol, about the early evolution of echinoderms, from worms to stars.

One of the most iconic animals to ever have gone extinct is the dodo, Raphus cucullatus. Endemic to Mauritius, this flightless bird was last seen around 1662 and is thought to have been driven to extinction by invasive species brought along by humans. Despite their relatively recent extinction, few dodo specimens remain. Discovering new material is therefore vital for our better understanding of this bird. One dodo-bearing locality is the 'Mare aux Songes', a marsh on the South-East of the island. Here Dr Hanneke Meijer, Institut Català de Paleontologia, has been excavating bones as part of the Dodo Research Programme.

Mammals are an incredibly diverse and highly successful group of animals. They include some of the tallest, heaviest and fastest animals around today, as well as our own species. For over 100 years, biologists have attempted to build mammal evolutionary trees using anatomical data. This work has provided the basis for our understanding of mammal relationships. Within the last 30 years, new technologies have enabled scientists to cheaply sequence molecular data (e.g. DNA and amino acid sequences) from thousands of mammal species. Interestingly, molecular trees reveal close relationships between some very different looking mammals. To guide us through this mammal renaissance, we are joined by Dr Robert Asher from the Department of Zoology at the University of Cambridge, UK.

Continuing our look at Australia's marsupials, we speak to Dr. Karen Black, also of the University of New South Wales. Here, we discuss Riversleigh fossil site, what fossils it contains, how they preserved and what's it takes to excavate them.

Marsupials are a group of mammals best known from Australia, but are also present in South America and up to the southern and eastern parts of the USA. Despite their current geographical distribution, metatherians (the group containing marsupials and other marsupial-like mammals) were once much more cosmopolitan; the earliest fossil evidence being from the Cretaceous of China, in the Northern Hemisphere. The story of marsupial evolution is therefore much more complex than is first apparent: When did metatherians and eutherians (placental mammals) diverge? Why are eutherians much more common? Why are metatherians restricted to the Southern Hemisphere? To answer some of these questions we spoke to Dr. Robin Beck, an expert on marsupial and metatherian phylogenetics, from the University of New South Wales, Sydney, Australia.

What are Mass extinctions, how are they quantified, what are the driving forces behind them, how bad were the ones in the past and will we have more in the future? To answer these questions we are joined by mass extinctions specialist Prof. Paul Wignall of the University of Leeds, UK.