The colour of dinosaur feathers
Melanin is a key colouring agent in the skin and hair of modern mammals and the feathers of modern birds. The characteristic melanin-bearing organelles called melanosomes have now been reported in the feathers of fossil birds and dinosaurs, including some of the earliest birds, as well as a broad range of flesh-eating dinosaurs, from the famous Jehol deposits of China, some 125 million years old. These structures have also been reported from other deposits, including the Cretaceous of Brazil and the Eocene (c. 50 million years ago) of Germany. Because feathers are such a key feature of birds, these discoveries will alow us to understand more about the origin of birds and the behaviour of dinosaurs and early birds. This theme is being explored actively in Bristol, in teams led by Professor Michael Benton and Dr Jakob Vinther, who is also exploring the wider question of original colours in a wide range of fossil organisms.
Vertebrate Biomechanics
Understanding the interaction of organisms with their environment is crucial to deciphering the selective pressures shaping their evolutionary history. As structure and function are governed by physical principles, the study of biomechanics can tell us much about the behaviour and evolution of both living and extinct animals. Research into evolutionary biomechanics in the Department of Earth Sciences is led by Dr Emily Rayfield and we currently employ a range of techniques such as CT, laser and neutron scanning, Finite Element Analysis (FEA), morphometrics and 'classic biomechanics' to address biomechanical problems in fossil vertebrates. Examples of current work underway include FE and morphometric studies on feeding and cranial construction in theropod dinosaurs, morphological disparity and function in extant and extinct crocodilians, the relationship between histology and function in extant mammals and its functional significance in extinct 'mammal-like-reptiles'.
Fossil Embryos
The Fossil Embryo Research Group is led by Professor Phil Donoghue. It looks at questions of evolutionary significance to the emergence of metazoans in the Ediacaran and Cambrian. A range of techniques are employed by the group, ranging from traditional palaeontology to developmental biology to particle physics. In collaboration with others, we are involved both with uncovering the piecemeal assembly of body plans, in the genetic controls on the embryology of living groups, and combining these two sources of information together to understand the how changes in the genetic regulation of embryology have led to changes in embryological programs, the origin of new body parts and the establishment of new groups of organisms. The group has strong links with other researchers with similar interests, placing it at the forefront of research in this area, in the world.
End-Permian Mass Extinction
The end-Permian mass extinction (EPME), 252 million years ago, was the largest mass extinction of all time. Some 80-95% of all species were wiped out, and yet the causes are still debated. Most evidence suggests that the killing was initiated by massive volcanic eruptions in Siberia which caused extreme global warming. In research led by Professor Michael Benton, we have been studying the nature of the event on land in the spectacular Permo-Triassic red bed sedimentary successions around the Ural Mountains in Russia. Following substantial funding from the National Geographic Society, the Royal Society, and NERC (2006-2011), we carried out field work from south to north, traversing into Arctic Russia. More recently, we have extended work on the EPME and Triassic recovery in the spectacular successions of marine sediments through the latest Permian continuously to the Late Triassic in South China.
Macroevolution
Palaeontologists make key contributions to our understanding of evolution in exploring the coming and going of major clades through time. These themes address fundamental questions of interest to many: why do groups appear and disappear through time, why do some groups become very species-rich and others do not, and is evolution progressive? New tools allow us to explore changes in diversity (taxon richness), relative abundance (ecological significance), and disparity (morphospace occupation; range of adaptation). Palaeobiologists have focussed on mass extinctions, but clade origins are more important for an understanding of evolution: they shape the bulk of biodiversity, and they are often associated with novelties, or remarkable sets of morphological adaptations. Our special contribution is to combine cladistic phylogenetic information with classic stratigraphic and statistical approaches to drill deep into the major events of the past. New work extends these palaeontological insights to combinations with phylogenomics in work led by Dr Davide Pisani that explores the deep origins of animals and their sensory systems.
Ocean acidification
The palaeontology and chemistry of the oceans today and in the past is part of wider research on palaeoceanographic and palaeoclimatic changes and the ecology and evolution of marine plankton, led by Dr Daniela Schmidt. Main research themes are evolutionary, ecological and mineralogical influences on the reliability of foraminifers as a recorder of proxies of past climate change, the influence of foraminiferal evolution on marine biogeochemical cycles such as long-term carbon storage in the deep sea and the effect of abrupt climate change on the extinction and evolution of plankton. Many techniques are used to tackle these questions, such as morphometrics, in-situ geochemical techniques to link morphology to isotopic and trace element changes, but also classical micropalaeontology. Current research is on the effect of environmental perturbations, such as ocean acidification and changes in ocean stratification, on foraminiferal carbonate production and hence the ocean's ability to absorb atmospheric CO2.
The Bristol Dinosaur Project
The Bristol Dinosaur was found in 1834, and named Thecodontosaurus antiquus. This was the first dinosaur in the world to be described from the Triassic, and only the fourth dinosaur ever named. During the 1830s, many more bones were found in old quarries in Clifton, Bristol. These quarries are now defunct, but in 1985 a further five tonnes of fossiliferous sediments with abundant Thecodontosaurus bones were found in a quarry near Bristol, and these are currently under study. This is perhaps the oldest reasonably complete herbivorous dinosaur in the world, and it will shed light on the origin of Dinosauria as a whole. We are carefully extracting the bones from the rock, a long and painstaking process that is being completed by technical staff in the Palaeo. Lab., and by student volunteers. Our long-term aims are scientific and educational: with substantial funding from the Heritage Lottery Fund, we are studying the anatomy and relationships of the beast and we plan to produce an interactive exhibit, displaying the dinosaur and its environment.
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