Russell Garwood, Author at PALAEONTOLOGY[online]

Dec12013

Life as a palaeontologist: Palaeontology for dummies, Part 1

by Russell Garwood *1 pa·lae·on·tol·o·gy / pa·le·on·tol·o·gy noun /ˌpælɪɒnˈtɒlədʒi/ or /ˌpeɪlɪɒnˈtɒlədʒi/ — The scientific study of prehistoric life. Introduction Palaeontology. If you’re reading this, it is likely that you’ve already encountered this particular corner of the scientific world, and know what it involves. If not, welcome: I think palaeontology is awesome and I hope that by the end of this article, you will too. Either way, it never hurts to define terms. As the above definition says, palaeontology is the study of prehistoric life. The discipline is actually rather wide ranging, with many sub-disciplines, but it is fair to say that most forms encompass the study of fossils or their traces. This study allows us to better understand extinct organisms’ biology, evolutionary...

Oct12013

Patterns in palaeontology: An introduction to ancient DNA

Patterns in Palaeontology

By Peter D. Heintzman*1 Introduction: Deoxyribonucleic acid, or DNA for short, is the magical molecule that encodes instructions on how to build organisms, and has been doing so successfully for at least the past 2.5 billion years. Although its function has remained constant throughout this time, the instructions themselves have been slowly modified and upgraded to cope with the changing demands of organisms and the environments in which they live. A modification to DNA is called a mutation, and it is through mutations that we are able to track how organisms have changed, or evolved, through time. In all multicellular organisms, there are two major types of DNA: mitochondrial (mtDNA) and nuclear (nuDNA) (Fig. 1). These have different histories and can therefore tell us different thing...

Aug12013

Patterns in Palaeontology: Why the thunder lizard was really the deceptive lizard.

Patterns in Palaeontology

by Chloe Marquart1 When I tell the average stranger that I'm a palaeontologist, the first question that I'm inevitably asked is: "Like Ross from Friends?" The second is: "Have you named any dinosaurs?" The naming of fossils is actually a very small part of the work that palaeontologists do, but it often garners the most attention from the press and public. It can be difficult for people to understand how scientists can suddenly decide that a well-known, often iconic name has never 'existed' - in a scientific sense, at least. Many grown adults still mourn the loss of their beloved Brontosaurus (more on him later), and in the past few years, campaigns were begun to ‘Save Triceratops’ when it was declared that this dinosaur and Torosaurus might be the same animal (Fig. 2). Although...

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 ...

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...

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...

Aug92012

Patterns in Palaeontology: The Cambrian explosion – Paradoxes and possible worlds

Patterns in Palaeontology

by Jonathan B. Antcliffe1 Introduction: The transition between the Precambrian and the Cambrian period (about 550 million to 500 million years ago) records one of the most important patterns of fossils in all the geological record. Complex animals with a suite of shells, intricate body plans and associated movement traces appeared for the first time, suddenly and unambiguously, in sequences all over the world during this interval. This ‘Cambrian explosion’ remains one of the most controversial areas of research in all of the history of life, and one of the most exciting. Palaeontological data like this is definitive in its support for evolutionary theory, the relative sequence of first appearances in the fossil record over the past several billion years ties very closely with what we wou...

Jun12012

Fossil Focus: Xiphosura

Fossil Focus

by Jason A. Dunlop*1 Introduction: The Xiphosura are commonly known as horseshoe crabs because the front part of their bodies is horseshoe-shaped. They have sometimes been called king crabs, although this name is also used for a group of large true crabs. Despite their various common names, xiphosurans are not crustaceans. Older studies assumed that they were some sort of crab, mostly because they have gills and live in the sea, but careful anatomical studies towards the end of the nineteenth century showed that they are actually more closely related to arachnids. The name Xiphosura means ‘sword tail’ and refers to another obvious feature of these animals: a long, pointed tail spine. Horseshoe crabs — especially earlier fossil ones — also look quite a lot like trilobites. This has led to...

Apr12012

Patterns in Palaeontology: Parsimony and Palaeobiology

Patterns in Palaeontology

by Javier Ortega-Hernández *1 Introduction: The principle of parsimony, also known as Occam’s razor, has been widely attributed to the English Franciscan friar William of Occam (c. 1288–1348). It states Pluralitas non est ponenda sine necessitate, which translates to ‘Plurality is not to be assumed without necessity’. In other words, when one is faced with a problem or question that can have several different answers, the solution that requires the fewest assumptions is most likely to be correct, unless there is evidence that proves that it is false. Parsimony has an enduring influence in most scientific activities, as it allows researchers to make comparisons and choose between different hypotheses that aim to explain a phenomenon using the same body of evidence. The incomplete nature...