Palaeontology [online]

May12017

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

Fossil Focus: Hallucigenia and the evolution of animal body plans

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...

Apr12017

Patterns in Palaeontology: Palaeoproteomics

Patterns in Palaeontology

by Caitlin Colleary*1 Introduction: The fossil record is our only direct window to the history of life on Earth. The ability to find and study the remains of animals, plants and other organisms that lived millions of years ago is extraordinary, and as technology has improved over the past few decades, scientists have realized that fossils contain more information about the stories of extinct life forms than even Charles Darwin could have imagined. Biomolecules (such as DNA, proteins and lipids) that make up modern animals contain information about how their bodies work (physiology — that is, physical and chemical functions), relationships to other animals and their evolutionary histories. With the advances in analytical tools such as high-resolution mass spectroscopy, the study of biomol

Mar12017

Fossil Focus: The First Mammals

Fossil Focus

by Elsa Panciroli1 Introduction: The study of the earliest mammals is an exciting part of palaeontology, telling us not only about strange animals that once lived on Earth, but also about how our own ancestors evolved alongside the dinosaurs. Early mammal fossils are very rare and often we only find a few teeth and bones, but we can tell a lot about the animals’ ecology and evolution from these remains. Discoveries of more-complete skeletons, particularly in China, are now revealing that early mammals were more successful and diverse than anyone had suspected. They specialized to exploit new habitats, diets and ways of living that would lead to their ultimate success. I want to give you an overview of the earliest mammals: mammals from the time of the dinosaurs. We will look at what d

Feb12017

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

Jan12017

Fossil Focus: The Ediacaran Biota

Fossil Focus

by Frances S. Dunn*1 and Alex G. Liu2 Introduction: The Ediacaran period, from 635 million to 541 million years ago, was a time of immense geological and evolutionary change. It witnessed the transition out of an ice-house climate, the break-up of one supercontinent (Rodinia) and the assembly of another (Gondwana), a major meteorite impact (the Acraman event) and unprecedented shifts in global ocean chemistry that included a significant rise in oxygen concentrations (Fig. 1A). Rocks from the Ediacaran also record the appearance of a diverse (species-rich) group of large, morphologically complex lifeforms: the Ediacaran biota. These organisms were globally abundant from about 571 million to 541 million years ago. To our modern eyes, many Ediacaran fossils look strange and unfamiliar, and

Dec12016

Fossil Focus: Sauropodomorpha

Fossil Focus

by David Button1 Introduction The sauropods are some of the most iconic prehistoric vertebrates. Their unique body plan — long neck and tail, bulky body and proportionately tiny head — is perhaps the most famous image of ‘a dinosaur’ and the group includes household names such as Brontosaurus, Diplodocus and Brachiosaurus. Sauropod remains have been found on every continent, and they were one of the most important groups of terrestrial giant plant eaters, or megaherbivores, throughout the Jurassic and Cretaceous periods (201 million to 66 million years ago). The single most notable sauropod trait is their gigantic size: the largest sauropods would have measured more than 40 metres from nose to tail, reached 18 metres tall and tipped the scales in the region of 60–80 tonnes, making them t

Nov12016

Fossil Focus: Acritarchs

Fossil Focus

by Heda Agić*1 Introduction: The acritarchs are a major, long-ranging and successful group of small, capsule-like, organically preserved fossils, which are present in the rock record of most of Earth’s history, dating back 1.8 billion year, or perhaps even as many as 3.4 billion years (Fig. 1). They include mostly single-celled microfossils ranging from a few micrometres (one-millionth of a metre) to one millimetre in size, and each is made up of a sac of organic tissue (vesicle). They are most commonly round, and can be either smooth or covered in spines (Fig. 2). Acritarchs are found in rock deposits that were once marine and terrestrial aquatic environments, and have been described from localities on all continents, as well as from all time periods from the Proterozoic eon (starting 2

Oct12016

Patterns in Palaeontology: From giants to dwarfs – Estimating the body mass of extinct species

Patterns in Palaeontology

by Charlotte Brassey1 Introduction Body mass is so fundamental to an organism that it is often overlooked, yet it has considerable importance in animal biology. It is, quite literally, the amount of matter making up an individual. On a day-to-day basis, we encounter values for body mass as we step onto our bathroom scales and are encouraged to maintain a healthy weight (not too heavy or too light). Veterinarians are interested in body mass for much the same reason: the weight of an animal can provide an indication of its health and is commonly used to plan medical treatments. Body mass is also tied to an animal’s physiology (including speed of metabolism and length of pregnancy), ecology (diet, home-range size) and behaviour (social status, aggression). For these reasons, zoologists are

Sep12016

Education and Outreach: Dinosaurs in the movies

Education and Outreach

by Szymon Górnicki*1 Introduction: Dinosaurs fit perfectly into the role of movie monsters: many were enormous, or had distinctive characteristics such as spikes, horns, claws and big teeth. The fact that they aren’t found in the modern world (except for birds) excites the imagination, and films represent some of the few opportunities to see them as they may have looked when they were alive. It’s not surprising that the history of movies featuring dinosaurs goes back more than 100 years. The cinematographic rise of the dinosaurs: The first moving picture featuring dinosaurs was Prehistoric Peeps (1905), an adaptation of a cartoon with the same name. The film launched the popular trend of showing primitive humans and non-avian dinosaurs living alongside one another, even though the foss

Aug12016

Patterns in Palaeontology: A story of vision

Patterns in Palaeontology

by James Fleming*1 Introduction: Photoreception, the ability to perceive light, is a sense shared by many living organisms on Earth. However, only some can take the step beyond merely detecting light levels, and generate an image. Humans are among the animals that have image-forming vision, and are able to see in colour in the day (polychromatic diurnal vision) and in black and white at night (monochromatic nocturnal vision) — the shades of colour that we pick up on an evening out trigger our diurnal receptors at very low levels. However, this is not the only way in which animals can see the world around them. Some species, such as whales and dolphins, can see only monochromatically no matter the time of day, while others see in colour no matter how dark it gets! The elephant hawk-mot