PALAEONTOLOGY[online]

Jul12013

Patterns in Palaeontology: Exceptional Preservation of Fossils in Concretions

by Victoria McCoy*1 Introduction: Have you ever seen a geode — a boring-looking ball-shaped rock that, when split open, reveals a remarkable crystalline interior? For most people, the first reaction to the dazzling crystal interior is to marvel at its beauty. But for some — and perhaps you fall into this group, since you are reading this article — the second and more important reaction is to wonder how it got that way. The people who ask this question understand that the beauty of nature is far greater when we understand it deeply and see it more fully; in short, they are scientists at heart. If you are a scientist at heart, I have very good news for you. There is something out there that is like a geode, but perhaps even more interesting, at least to fossil lovers: the curious rocks ...

Jun12013

Patterns in Palaeontology: Development in the Fossil Record

Patterns in Palaeontology

By Jo Wolfe*1 Introduction: Development, the process by which a single egg cell transforms into a complex adult organism, has fascinated biologists for more than 200 years. In the mid-nineteenth century, before and during the time when Charles Darwin was uncovering the principles of natural selection, a number of biologists who wondered what caused evolutionary relationships among organisms looked to development for answers. The German zoologist Ernst Haeckel popularized the phrase “Ontogeny recapitulates phylogeny” — where ontogeny is an organism’s development and phylogeny is its evolutionary relationships. You may have seen a version of his famous diagram in biology textbooks (Fig. 1). Haeckel suggested that, during each successive stage of development, an animal would pass through a ...

May12013

Fossil Focus: Trilobites

Fossil Focus

by Mark Bell*1 Introduction: Trilobites make up one of the most fascinating and diverse groups in the fossil record. Over the course of their long history — which dates back to near the beginning of the Cambrian period, around 520 million years ago — they have inhabited a wide range of marine environments, from reefs to abyssal depths. In addition, trilobites have evolved several different life strategies, from burrowing to swimming; these are reflected in their varied appearances, or morphologies (Fig. 1). Several species, famously those from the Devonian period of Morocco (about 420 million to 360 million years ago), developed a rich array of protective spines, which has made them a popular choice among fossil collectors and dealers. The earliest scientific report of a...

Apr12013

Patterns in Palaeontology: Who’s there and who’s missing?

Patterns in Palaeontology

by Simon Darroch*1 Introduction: Sitting in the sweltering heat of southern Japan, I’m faced with a conundrum. The limestone cliff in front of me preserves the boundary between the Permian and Triassic periods, a point in time around 250 million years ago that witnessed the greatest mass extinction of the Phanerozoic eon. I’m collecting rock and fossil samples from around this boundary to study how the make-up of fossil communities changed in response to this extinction event: this is palaeoecology. The boundary itself couldn’t be easier to spot — the lower (and older) part of the cliff is composed of a pale white-yellow limestone packed full of fossils of shelled marine invertebrates including brachiopods, bivalves and gastropods, as well as microscopic sea-floor-dwelling (benthic) crea...

Mar12013

Fossil Focus: The evolution of tree-kangaroos

Fossil Focus

by Christine Janis1 Ladies and gentlemen, I give you tree-kangaroos. These wonderful animals can, in myriad ways, demonstrate the power of evolutionary biology and geology in explaining the patterns we see in modern ecosystems. Here, I want to show how palaeontologists can piece together multiple lines of evidence to understand the evolutionary relationships of fossil and living organisms. Introduction First, a little introduction to the tree-kangaroos (genus Dendrolagus). These small, tree-dwelling (‘arboreal’) marsupials live in the rainforests of Australia and New Guinea, and belong to the macropod family of animals, which also includes ground-dwelling kangaroos and wallabies. They grow up to about 80 centimetres long, not including the tail, and mainly eat vegetation (see Fig...

Feb12013

Patterns in Palaeontology: Old shapes, new tricks — The study of fossil morphology

Patterns in Palaeontology

by Verity Bennett1 Introduction: The size and shape of an organism is the product of genetics and environment. It is the raw material on which the process of natural selection (survival of particular animals over others) acts, and so is of central interest in studies of the evolution of ancient forms of life for which DNA information is not available. Fossil morphology, or shape, is the basis of most palaeontological studies, be they describing new species or making deductions about the animal’s lifestyle. Phylogenetic studies, those that place species in groups depending on how closely they are related to each other, are based on the presence and absence of particular features. This works on the theory that the more closely related two animals are, the more features they are likely to h...

Jan12013

Life as a Palaeontologist: Going solo and making a living out of working with fossils

Life as a Palaeontologist

by Leyla Seyfullah*1 Introduction: In an article on Palaeontology [online] last year, Sarah King explained how undertaking a PhD can help you to launch an academic career in palaeontology. Obtaining that PhD can be a frustrating yet ultimately rewarding experience, but it is only the beginning for many palaeontologists — and it is worth pointing out that a PhD isn't a prerequisite for certain jobs in palaeontology (for example, dealing fossils). Here, I hope to give you a sense of what might happen after the PhD, and how this could lead to a wide range of new challenges and take you down previously unimagined paths. You didn't think that getting a job in palaeontology would be straightforward, did you?! As a PhD (Doctor of Philosophy) student, you are dedicated to working on your doct...

Dec22012

Life as a Palaeontologist: Academia, the Internet and Creative Commons

Life as a Palaeontologist

by Ross Mounce*1 Introduction: The results of scientific research can be of interest to experts and non-experts alike. This is perhaps especially true for palaeontology, which captures public interest — but obtaining access to this information is sometimes difficult, even for scientists. Taking a rather different tack from previous Palaeontology [online] articles, I'm going to provide a brief overview of how the Internet has changed and is significantly changing palaeontology and academia in general, helping to open up research for the greater benefit of science and society. Figure 1 — Sir Tim Berners-Lee sends a message at the London 2012 Olympics. When Sir Tim Berners-Lee helped to invent the World Wide Web more than 20 years ago, he did it 'for ever...

Nov12012

Patterns in Palaeontology: The first 3 billion years of evolution

Patterns in Palaeontology

by Russell Garwood *1 Introduction: Breathe in. Breathe out. It’s a good bet that you’re currently sitting in front of a computer, reading; I’m going to go ahead and assume that you’re breathing, too. In, and out. You probably weren’t even thinking about breathing until I mentioned it, but all the same, it’s keeping you alive. Oxygen from the air is being transported into the cells of your body, which are using it to create energy. So far, so good. But what you may not realize is that the cellular machinery performing this process so integral to our existence (Fig. 1) has roots buried deep in the geological past. It’s a story that begins before the origin of organized cells, in an ancient, alien world. But if we’re going back that far, we might as well go all the way back, to the very be...

Oct12012

Fossil Focus: Marsupial evolution – A limited story?

Fossil Focus

by Verity Bennett*1 Introduction: There are three groups of mammals alive today: the egg-laying monotremes (echidnas and platypuses); the marsupials (those with pouches); and the placentals (those that develop a placenta in the womb and give birth to comparatively developed young). Marsupials and placentals are sister groups, more closely related to each other than to monotremes. Along with their closest fossil ancestors, marsupials belong to the clade metatheria, whereas placentals belong to the clade eutheria. Together, metatheria and eutheria comprise the therian mammals. Marsupials are much less diverse than placental mammals in terms of numbers of different groups, range of lifestyles, range of body shapes and where they live. Why this is the case is still not well understood, and a...