by Aodhan Butler *1 Introduction: Darwin, the Cambrian explosion and the origin of animals. The small shelly fossils (or SSFs) of the early Cambrian period (approximately 541 million to 509 million years ago) could in many ways be described as the world’s worst jigsaw puzzle. This article will attempt to give a brief tour of the significance, history and biology of this humble yet potentially hugely important group of fossil organisms and how they may help in answering fundamental questions about how and when the major groups of animals evolved on Earth. A palaeontological mystery… “To the question why we do not find rich fossiliferous deposits belonging to these assumed earliest periods prior to the Cambrian system, I can give no satisfactory answer.” Charles Darwin, On the Origin of
by Joshua Ludtke*1 Introduction: Oreodonts make up an extinct group of small, medium and large hoofed mammals. They are among the most commonly represented mammals in more than 40 million years of the North American fossil record; among completely extinct groups, the oreodonts may be the most abundantly preserved group of fossil mammals. This abundance has allowed them, after their extinction, to spread across the globe. Since at least the 1840s, fossil collectors from around the world have visited the North American west to excavate oreodonts, and their fossils have ended up in both public museums and private collections worldwide (see Fig. 1). What is an oreodont? Oreodont is the informal term for any member of the taxon Merycoidodontoidea. Oreodonts are placental mammals; some f...
by Marc Laflamme*1 and Paul A. E. Piunno1 Introduction: Scientific research is becoming increasingly interdisciplinary, drawing together experts from a range of fields to generate knowledge and address major problems. This is particularly true for palaeontology, which stands at the intersection of a wide array of disciplines including geology, biology, chemistry, materials science, statistics and biomechanics. Although scientific innovation is principally driven by trained scientists, research opportunities often present themselves to others — in palaeontology, this can tie into the strong public interest in famous extinct animals such as dinosaurs and mammoths. Indeed, palaeontology has an extensive history of important contributions by people without formal training, from Mary Anning’s
by David A. Legg*1 Introduction: The arthropods make up a major and highly successful group of animals that includes insects and their kin (hexapods); arachnids and their kin (chelicerates); millipedes and centipedes (myriapods); crabs, lobsters, shrimp and their relatives (crustaceans); and the extinct trilobites. In fact, arthropods are the most diverse, abundant and ubiquitous animal phylum. Members of the group outnumber those of all other phyla on Earth, both in terms of species, with more than 1,200,000 currently described (and a potential 10,000,000 remaining to be described), and in terms of abundance. For example, if you gathered all the world’s Arctic krill in one place, it has been estimated that they would weigh 500 million tonnes! Arthropods are found in all oceans and on al
by Ellen Currano1 “It’s a dangerous business, Frodo, going out of your door,” he used to say. “You step into the road, and if you don’t keep your feet, there is no knowing where you might be swept off to.” — J. R. R. Tolkien The Fellowship of the Ring (Ballantine Books, 1954). Introduction: It was never part of my plan to become the (sometimes bearded) face of women in palaeontology. I was that first grader who fell in love with dinosaurs and set her heart on becoming a palaeontologist. Since I started college, my dream has been to work at the University of Wyoming, travel the world digging up fossils, publish papers in scientific journals and, if I was lucky, be asked to give public lectures on my work. In other words, I wanted to emulate the professors at the top-tier research insti
by Sven Sachs1 and Benjamin P. Kear2 Introduction: Elasmosaurs were a group of marine reptiles that lived during the Cretaceous period (about 145 million to 66 million years ago). They were fully adapted to an aquatic lifestyle, and had a distinctive body plan comprising a compact, streamlined body, long, paddle-like limbs and an extremely elongated neck with a large number of vertebrae (Fig. 1). The first named elasmosaur was Elasmosaurus platyurus from the Late Cretaceous (Campanian stage, about 83.6 million to 72.1 million years ago). It was found in Kansas and described by the famous US scientist Edward Drinker Cope (1840–97, Fig. 2), who, when he first wrote about it in 1868, believed that the almost complete series of 72 neck vertebrae came from a massively long tail. Today, many
by Stephen F. Poropat*1,2 Introduction: Ask the average person in the street to name an Australian dinosaur, and you will be lucky if you get a correct answer. If they say crocodile, they are in the right postcode but have the wrong address. If they say emu, then they are correct, strictly speaking, but they are either lucky or being smart. If they say kangaroo, back away slowly and avoid eye contact. If they say koala bear, run home and take a few Panadol. I could forgive most people for not being able to identify any Australian dinosaurs. First and foremost, there are not many to know: only 18 Australian dinosaurs (including one bird, Nanantius) from the Mesozoic era (251 million to 66 million years ago) have been officially named. And yet, the first discovery of Mesozoic dinosaur r...
by Dave Hone(1) Introduction: Thanks to Tyrannosaurus rex, the tyrannosaurs are among the most famous of the extinct dinosaur groups. They receive a disproportionate amount of attention in the media and hold a firm place in the public imagination. However, this also means that more misconceptions and out-of-date ideas are promoted for this group than any other, and the excess of attention detracts from the fact that they are a genuinely interesting clade of animals. In fact, thanks to a great deal of research effort, we may know more about tyrannosaurs than any other group of dinosaurs from the Mesozoic era (252 million to 66 million years ago). This alone makes them a key part of palaeontology. All tyrannosaurs were carnivores, and although the most famous forms from the last part o...
by Luke Parry*1 Introduction: Annelids, whose name comes from the Latin meaning ‘little ring’, make up a phylum of invertebrates with a unique segmented body plan. They are important components of terrestrial and marine ecosystems, and form one of the most diverse invertebrate groups, including as many as 15,000 described species (Fig. 1). Their closest living relatives are the molluscs, brachiopods and nemerteans (proboscis worms). Annelids can broadly be split into two groups, the polychaetes and clitellates. These groups share many features, such as segmented bodies and paired bundles of bristles made of chitin, called chaetae or setae. The most familiar annelids are the clitellates — the earthworms, leeches and their relatives — which have become adapted to a terrestrial lifestyle
by Rachel A. Racicot*1 Introduction Porpoises are among the smallest of modern whales, but they are one of the most amazing groups. They use specialized high-frequency hearing and sound production, and they have one of the best fossil records of any marine mammal. Thanks to modern imaging technology, we have been able to learn about how porpoises are able to sense their environment through echolocation and how they evolved. I will be telling you a bit about a particularly interesting porpoise from the fossil record, Semirostrum ceruttii (‘Cerutti’s half-nose’), and using it as an example of how CT scans help scientists to explore ancient and modern anatomy. What are porpoises? People sometimes use ‘porpoise’ interchangeably with ‘dolphin’, but scientists use the term to refer to a dist