by Amelia Penny*1 Introduction and background The ability to build and maintain a skeleton is one of the major innovations in the history of life. During the Cambrian explosion, which began around 540 million years ago, diverse animal (metazoan) skeletons appeared suddenly in the fossil record. This is also when we first see evidence for predation, the ability to move around and most of the animal body plans we would recognize today. The ability to grow a resistant skeleton was a major factor in the evolutionary arms races of the Phanerozoic eon — the time since the Cambrian explosion — and it made possible the dizzying variety of shells, bones and teeth scattered throughout the Phanerozoic fossil record. But the origin of skeletons has a much deeper root, in the Proterozoic eon (2,500 m
by Janet Burke*1 Introduction and background: Although the microscopic creatures called planktonic foraminifera are still around today, most people have not heard of them. They don’t come to mind when the words "palaeontologist" or "fossil" are mentioned. They don’t have scales or claws, or big sharp teeth. They don’t even have mouths. If you were to visit the lab I work in, you wouldn’t see the specimens, just a row of compound microscopes and funny metal trays, slides and boxes of glass vials a little bigger than a pinky finger. If you look closer at those vials, each one contains hundreds upon hundreds of fossils, and each of those fossils has a story to tell. Etched into the nooks of its chambers and the very molecules of its calcite are facts about the ocean at a brief moment in tim
by The Palaeontology [online] editorial board*1 Introduction Every now and then at Palaeontology [online], we like to take a look at the world of palaeontology and reflect on what is happening in the field. Contrary to stereotypes, we believe that palaeontology and associated disciplines represent a fast-moving and exciting area of science. To highlight this, the members of the editorial board have each chosen a favourite paper from 2017. Picking just one paper was difficult for all of us, and it means that we have highlighted just five articles out of the many hundreds published in the past 12 months. Nevertheless, we hope that our choices reflect the breadth and depth of palaeobiological research in the twenty-first century. The papers include incredibly small and ancient invertebrates...
by Aodhán O'Gogain*1 Introduction and background During the Pennsylvanian subperiod (roughly 318 million to 299 million years ago), lush tropical rainforests covered much of what is now North America and Europe, but were then near Earth’s Equator. These tropical forests were teeming with animals, from 2-metre-long millipedes that scurried along among the roots to fish with fangs 10 centimetres in length that inhabited the associated rivers and estuaries. Living among these giants was a diverse group of small (less than 1 metre) vertebrates that resembled newts, lizards and snakes. These were the Lepospondyli, a sub-class of tetrapods that are characterized by having hourglass-shaped centrums, the central parts of their vertebrae. They had elongated, small bodies and short limbs, with one
by Lukáš Laibl*1 Introduction: Trilobites are an iconic group of ancient animals, with a fossil record that dates back more than 500 million years and consists of some 17,000 species. These extinct arthropods are characterized by a hard, mineralized exoskeleton, which greatly enhances their chances of being preserved as fossils. The exoskeleton is thought to have been mineralised soon after they hatched from eggs, and so we can find various growth stages of trilobites in the fossil record, including individuals less than half a millimetre long. That makes it possible to study the entire post-embryonic development (that is, the development after they hatch from the egg) of numerous species. This is important because work on the development of ancient organisms provides data crucial for ou
by Szymon Górnicki*1 Introduction: Non-avian dinosaurs are iconic animals that dominated life on land for 170 million years during the Mesozoic era, and have captured the imagination of scientists and non-scientists alike for as long as we have known about them. As a result, dinosaurs have also dominated palaeoart — artistic representations of past life. Palaeoart is closely linked to the science of palaeontology, resulting from the desire to reconstruct what extinct organisms looked like when they were alive, and is increasingly informed by the latest scientific discoveries. This article provides a brief historical account of dinosaur palaeoart, explaining how this work has changed as our understanding of the anatomy and biology of dinosaurs has improved. Scaled-up lizards: The first
by Robert Brocklehurst*1 Introduction and background Dinosaurs fascinate people more than almost any other group of fossil animals, and the general public is interested in many open questions on dinosaur biology. How fast could dinosaurs run? Were they warm blooded? If they had feathers, does that mean they could fly? These questions focus on dinosaur metabolism and movement, both of which are intimately linked with the respiratory system, because breathing — the ability to take in air, extract oxygen from it and then expel it from the body along with waste carbon dioxide— sets a fundamental upper limit on how much activity an organism is capable of. How did dinosaurs breathe? That’s probably not a question palaeontologists get asked as often as the others. Breathing is something we a
by Brittney Stoneburg*1 Introduction: Natural history museums are not just exhibit space: a lot of scientific research is conducted behind the scenes. This is the nature of almost any museum. It is often not logistically or financially possible to exhibit every object, and not every fossil is suitable to go on display. The fossils that the public doesn’t see are still important for research, but this is a part of museum work that is often hidden from the public at large. I work at the Western Science Center in Hemet, California. Visitors have no access to our repository, and are often amazed when they learn that less than 5% of our palaeontology collections can currently be seen. Through an upcoming exhibition and scientific workshop, we are endeavouring to use exhibit space and the I
by Thomas W. Hearing*1 Introduction: Shimmering curtains of sunlight stream down through the waters of a shallow sea that has been advancing landwards for several million years. This transgression has formed wide areas of shallow continental shelf seas. The sea bed teems with life — some of it familiar, some much less so. The oddities begin on the floor of this tropical sea: a reef built not of corals, but by carbonate-producing microbes and the strange archaeocyathan sponges, alongside creatures that look more conventionally sponge-like but probably aren’t. Streams of seaweed drift on the currents; closer examination reveals small, snail-like shelled molluscs on some of the tendrils. A trilobite scuttles for cover, startled by the flickering shadow passing overhead, and narrowly avoids
by Martin Smith*1 Introduction: Five hundred and fifty million years ago, few (if any) organisms on Earth were much more complex than seaweed. But this would not be the case for long: during a profound evolutionary event dubbed the Cambrian Explosion, natural selection generated the raw material of all the body plans we see in the oceans today. Fossil sites from midway through the Cambrian period (541 million to 485 million years ago) preserve organisms that could almost be mistaken for modern eels, jellyfish, shrimp and squid, along with members of most other major animal groupings (phyla) recognized by biologists today. But the exceptional fossil deposits of the Cambrian period, some of which preserve fleshy bodies as well as the skeletons and bones that make up a typical fossil, al...