Palaeocast

The ‘Crystal Palace Dinosaurs’ are a series of sculptures of extinct animals including dinosaurs, other extinct reptiles and mammals, which can be found in the grounds of the Crystal Palace in London. Commissioned in 1852, these are the earliest examples of dinosaur sculptures in the world. In fact, the first dinosaurs had only recently been discovered some 30 years earlier. Why were these models built? And what do they tell us about early scientific hypotheses of dinosaurs and other extinct animals? To answer these questions we talk Joe Cain, Professor of History and Philosophy of Biology at University College London.

Ankylosaurs are a group of non-avian dinosaurs best known for their armour, tank-like bodies, and sometimes large tail clubs. First appearing in the Jurassic, they were common in Late Cretaceous ecosystems, with several species known from around the world. But how different were these species really? And just where did they evolve from? What was that tail for?

Dr. Victoria Arbour of the North Carolina Museum of Natural Sciences is one of the leading experts on ankylosaurs, and has published a number of papers, including a recent study on how the tail club evolved. We spoke with Victoria about these dinosaurs and she answered some of these questions for us.

Melanin is a pigment that is found across the animal kingdom. Melanosomes, the organelles that contain melanin, have been found preserved in fossil feathers and melanosome shape has been used to infer the original colors of birds and dinosaurs. Today we’re talking to Caitlin Colleary whose paper - on her Masters research at the University of Bristol - delves into detail regarding the structural and chemical preservation of melanin and describes the color of a fossil mammal for the first time.

The Symposium of Vertebrate Palaeontology and Comparative Anatomy (SVPCA) annual conference was held at the University of Southampton National Oceanography Centre at the beginning of September. This is the first year we've covered this event, and covered a wide range of topics in vertebrate palaeontology. We spoke to several people, which you can listen to here, including information on Romanian and Hungarian fossils, ceratopsian dinosaurs, ankylosaur histology, sesamoid bones, and more.

Eurypterids, or ‘sea-scorpions’ are an extinct group of chelicerates: the group containing the terrestrial arachnids (such as spiders and scorpions) and the aquatic ‘merostomes’ (represented today solely by the horseshoe crabs). They bear a gross-morphological resemblance to scorpions (hence the informal name) but, in being aquatic, may have shared more in common with horseshoe crabs. They inhabited the waters of the Paleozoic Era and were typically scavengers or predators. Most eurypterids were quite small and unremarkable, but some genera, such as Pterygotus and Jaekelopterus grew to incredible sizes; the latter reached an estimated 2.5m (8’ 2”) and is still the world’s largest-known arthropod.

Described today in BMC- Evolutionary Biology is the oldest-yet-described eurypterid Pentecopterus decorahensis and we've got lead author Dr James Lamsdell, Yale University, to introduce us to the eurypterids and to discuss the significance of this new genus.

On today's episode we're revisiting Mistaken Point, Newfoundland, Canada. At this lagerstätte it is possible to find large bedding planes full of Precambrian organisms called rangeomorphs. These are an enigmatic group, which still can't be placed on the 'tree of life'.

We are joined by Dr Emily Mitchell of the University of Cambridge, who's recent paper in Nature was able to show that you don't need to be able to fully understand the anatomy of an organism to discern some of its most intricate details.

Synapsids are one of the major groups of terrestrial vertebrates. They first appear in the Carboniferous period and since that time have gone through many radiation and extinction events. But what did these first stem-mammals look like, how did they live and how do they differ from modern mammals? These may sound like simple questions, but there is an underrepresentation of terrestial deposits from the Permian. How then can we understand larger-scale evolutionary patterns when so much data is missing?

The Burgess Shale is probably the world's most famous lagerstätte (site of special preservation). Discovered in 1909 on Mt. Stephen, in the Canadian Rockies of British Colombia, Canada, this locality provided an early representation of the true biodiversity of the Cambrian Period. For decades, discoveries from this site have helped palaeontologists better understand the 'Cambrian Explosion' and the origins of modern lineages. Since that time, many more early lagerstätten have been discovered, so we asked Prof. Simon Conway Morris, from the University of Cambridge, if this well-studied locality still holds its relevance to modern palaeontology.

It's been quite a week for lobopodians!

First off, we've had the redescription of Hallucigenia by Dr Martin Smith. This enigmatic fossil from the Burgess Shale typifies the difficulty palaeontologists have had in interpreting some of the earliest animals in the fossil record. It has famously been reconstructed upside-down and is now shown to also have been back-to-front too! Dr Smith joins us to tell us about the observations, including some new anatomical characters, that put an end to the uncertainty of the orientation of this animal.

Secondly, there's a older and more heavily-armoured lobopodian from the early Cambrian Xiaoshiba biota of China that we've got the exclusive on. Collinsium ciliosum is described today and we're also joined by one of the lead authors Dr Javier Ortega-­Hernández.

The world is currently undergoing a massive biodiversity crisis, and many people have said that we are in the next major mass extinction event, with species going extinct each day. Unfortunately, we don't currently understand what aspects control biodiversity, and how the past can help us understand the present and the future.

Associate Professor Lindsey Leighton of the University of Alberta discusses his work combining research of modern invertebrate marine fauna related to biodiversity and ecosystems with studies of the fossil record in order to further understand this problem.