www.palaeontologyonline.com

Author: Russell Garwood

Fossil Focus: The Archosaur Respiratory System — Or — Breathing Life into Dinosaurs

Fossil Focus: The Archosaur Respiratory System — Or — Breathing Life into Dinosaurs

Fossil Focus
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
Fossil Focus: <i>Hallucigenia</i> and the evolution of animal body plans

Fossil Focus: Hallucigenia and the evolution of animal body plans

Fossil Focus
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...
Perspectives: Fossils and the Law — A Summary

Perspectives: Fossils and the Law — A Summary

Perspectives
by Jack J. Matthews1 Introduction: Geoconservation, also known as Earth Heritage Conservation, is how we protect important examples of Earth’s physical resources. Geological features can be protected for all sorts of reasons, including being important to cultural heritage, geological education and understanding, or the overall aesthetics of an area. A great many designations, management frameworks and legal instruments have been used to govern and protect fossil-rich outcrops in the United Kingdom, but these are poorly publicized and, for example, rarely taught to palaeontologists as part of an undergraduate degree. Field work is an important part of palaeontological research, so it is a good idea for everyone who works with fossils, whether amateur or professional, to have a good und
Patterns in Palaeontology: How and why did the arthropod shed its skin? Moulting in living and fossil arthropods

Patterns in Palaeontology: How and why did the arthropod shed its skin? Moulting in living and fossil arthropods

Patterns in Palaeontology
by Harriet B. Drage*1 Introduction: Arthropods are one of the most successful groups of animals, in the present day and the fossil record. There are more than 1 million described arthropod species, and it has been estimated that there are at least 5 million more undescribed alive today (Fig. 1). This makes up more than 80% of all known animal species! Arthropods also have an extremely diverse fossil record, extending back to the Cambrian Explosion 541 million years ago. For much of the Palaeozoic era (541 million to 252 million years ago), arthropods dominated marine ecosystems, and they have been significant components of all environments since then. The phylum Arthropoda encompasses insects (Hexapoda), crustaceans (such as shrimps and lobsters) and arachnids (such as spiders), a...

Fossil Focus – Marrellomorph arthropods

Fossil Focus
by David Legg*1 Introduction: The Palaeozoic era was a time of incredible biological diversification, which saw the origins and establishment of most modern animal body plans and phyla, particularly during the Cambrian explosion, an event which lasted for about 20 million years during the early Cambrian Period (starting about 542 million years ago), and the subsequent Great Ordovician biodiversification event. During this time, there was a lot of ‘evolutionary experimentation’, with many ancient communities dominated by alien-looking creatures unlike any of their modern counterparts. One such peculiar group is the marrellomorph arthropods, roughly 11 species known exclusively from the lower Cambrian (starting about 542 million years ago) to the lower Devonian period (ending about 393 mil

Fossil Focus: Ammonoids

Fossil Focus
by Kenneth De Baets1, René Hoffmann2, Jocelyn A. Sessa3 and Christian Klug4. Introduction: Ammonoids (Ammonoidea) are an extinct group of marine invertebrates with an external shell. They were cephalopods, and hence closely related to modern cuttlefish, squid, octopuses and the pearly nautilus. In a non-scientific context, they are commonly called ammonites, but that term really includes only Jurassic and Cretaceous forms in its stricter scientific sense. The Ammonoidea as a whole lived from the Early Devonian to the earliest Palaeogene period, covering a timespan of about 350 million years. Normally, only their shells, also called conchs, or their internal moulds are found in the fossil record. Conchs from adult ammonoids range from about 5 millimetres to 2 metres in diameter. Due to

Perspectives: 2015 in Palaeontology

Perspectives
by the Palaeontology [online] team Introduction: We’re now into our sixth volume — and calendar year — at Palaeontology [online]. Over the years, we have introduced a lot of fossil groups, concepts from palaeontology and overviews of different parts of our field. An intention when we started was also to provide the occasional overview of happenings in the world of palaeontology: to reflect new developments and highlight some current ideas. To that end, we have chosen to start 2016 by looking back over the past year, and forward into the next. In this article, members of the Palaeontology [online] team have chosen their favourite papers from 2015, and indicated what they hope to be up to over the next 12 months. So without further ado, here is team Palaeontology [online]! Imran Rahman:

Fossil Focus: The place of small shelly fossils in the Cambrian explosion, and the origin of Animals

Fossil Focus
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

Fossil Focus: Cambrian arthropods

Fossil Focus
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

Fossil Focus: Annelids

Fossil Focus
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