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Western Australian Museum

Country: Australia
2 Projects, page 1 of 1
  • Funder: UKRI Project Code: ST/F003072/1
    Funder Contribution: 300,619 GBP
    Partners: Western Australian Museum, Academy of Science of the Czech Republic, Imperial College London, Natural History Museum, OU, Exscitec Ltd

    A spatial context to aid interpretation is fundamental to all sample analysis: whether those samples are rocks, medical tests, or police evidence, we need to know where they came from to interpret the results. Meteorites are our only samples of a protoplanetary disk; the only surviving physical record of the formation of our own Solar System (including the variety of local stellar sources that contributed to our disk, and the chemical processes that occurred within it); the only record of how differentiation and core formation occurs in planetesimals. And yet we have virtually no constraint on where they come from. Until we get sample-return missions to numbers of asteroids, what we need are orbits for specific meteorites. Unfortunately, out of tens of thousands of meteorites, we have good orbits for only four, and reasonable orbits for a couple more. The aim of this project is to determine orbits for numbers of meteorites. The results potentially have implications for every area of meteorite study, just as a knowledge of spatial context of any other sample has implications for all subsequent analyses of it. Meteoroids produce a bright fireball as they transit our atmosphere. By photographing the fireball from different angles, the atmospheric track of the object can be determined with great accuracy. If material survives to the surface as a meteorite, this allows us to work out what its orbit was before it entered the atmosphere, and also where it landed on the Earth's surface. This technique has been employed a number of times over the last 50 years, all in temperate regions of the northern hemisphere, but although hundreds meteorite falls have been observed, only four were recovered. The poor success rate is down to the difficulty in recovering a small rock in an area of several square kilometres when there is significant undergrowth. Our solution was rather simple. Over the last few decades, tens of thousands of meteorites have been found in the world's deserts. Put a fireball network in a desert and it should be much easier samples. We have designed a fireball observatory that can operate automatically in the harsh environment of the Australian desert. Based on previous fieldwork in this area, looking for old weathered meteorites, we should have about a 70% chance of finding meteorites that we see land. Our first grant, to put a small network of 3 observatories out in the desert, and test both the technology and concept, began June 2005. Two years on, fireball observatories have been built, deployed in the Australian desert, and successfully integrated with satellite internet and solar power. In addition to fully-functioning autonomous observatories, logistics to maintain them in operation, and support regular fieldwork, are in place. The UK now has a fireball camera network operating in the Australian desert. Orbits have been calculated from 22 fireballs - the first orbits to be determined from southern hemisphere fireballs. And most important: at least one of these fireballs has produced a meteorite on the ground. An expedition to recover this sample - and any others that fall in the meantime - will be mounted in the next field season. Our initial trial network has proven a success. We now need the support that will let us translate this success into a growing collection of meteorites with orbits, finally providing meteorite scientists with that most basic information: a knowledge of where their samples come from.

  • Funder: UKRI Project Code: NE/P013090/1
    Funder Contribution: 419,180 GBP
    Partners: Swedish Museum of Natural History, RAS, University of Cambridge, SIA, AUSTRALIAN NATIONAL UNIVERSITY, Western Australian Museum, RVC, The Great North Museum: Hancock, University of Bristol, University of Ottawa...

    Our proposal brings together world class expertise and cutting-edge methods to answer a key question in the history of life: how did vertebrates conquer the land? We address this question by testing four key hypotheses derived from long-standing assertions that selection acted upon the skull to drive adaptations for improved terrestrial feeding during the water to land transition. Our methods offer a means to shift away from analogy-driven assertions of evolutionary history towards rigorous testable hypotheses founded upon mechanical principles, and will set a benchmark for future studies in evolutionary biomechanics. For the first 200 million years of their history, vertebrates lived an aquatic existence. Between 385 and 350 million years ago they evolved a host of anatomical features that ultimately enabled vertebrates to conquer land. This reorganization of the vertebrate skeleton created the basic tetrapod body plan of a consolidated head with mobile neck, arms and legs with digits and air breathing lungs. This plan has persisted, subject to modification, ever since and is shared by all terrestrial vertebrates. It was proposed over 50 years ago that tetrapods modified their skull bones and jaw muscles to create a stronger and 'more efficient' structure, capable of forceful biting for feeding on land. This reorganization is seen as key to their subsequent radiations, enabling tetrapods to expand into new ecological niches by feeding on terrestrial plants, large prey and hard or tough food. It has been proposed that these modifications came at the cost of reduced hydrodynamic efficiency and a slower bite, and could only be achieved by the loss of suction feeding and the evolution of rib-based breathing, thus freeing the skull from its roles in aquatic locomotion, drawing prey into the mouth and pumping air into the lungs. These ideas have been perpetuated in textbooks for decades, yet are based on out-dated simple line drawings of skulls and jaw closing muscles, and remain to be tested. We now have a rich and informative fossil record that documents changes in skull shape across the water to land transition. However, until now, we have lacked the means to test these hypotheses in a quantitative, rigorous way. In this proposal we will determine how changes in skull form and function enabled vertebrates to feed in a terrestrial environment and document the sequence of evolutionary changes and trade-offs that lead to their conquering of land. We will integrate principles from palaeontology and biology to reconstruct skull anatomy in 14 fossil tetrapods. Mathematical and mechanical principles will then be used to test the hypothesis that changes to skull anatomy resulted in tetrapod skulls evolving from hydrodynamically streamlined broad, flat skulls that could deliver a rapid (but weak) bite to strongly built skulls that could produce a more effective, forceful bite. New evolutionary modelling methods will assess how selection for skull strength or hydrodynamic efficiency shaped the evolution of the tetrapod skull. Our project will produce methodological advances that can be applied more broadly to evolutionary transitions and radiations, and to address long standing questions linking form and function. Palaeontologists, anatomists, biomechanists, evolutionary and developmental biologists and engineers will benefit from this work, which will establish new international collaborations. Its visual aspect and focus on early tetrapods will appeal to the general public, offering engagement opportunities and generating media interest. Members of our team are leaders in developing and validating methods for reconstructing and simulating the musculoskeletal anatomy and function of fossil organisms and have been involved in developing new methods for modelling how function has shaped form in deep time. The time is therefore ripe to apply our knowledge and skills to one of the key events in the history of life and our ow