A funded PhD opportunity is available for a project supervised by myself and my colleague Rob Sansom, titled The timing and modes of macroevolutionary change: molecules, morphology, and simulations. If you're interested in real-world data, simulations and evolution, please don't hesitate to get in touch if you have any questions! Deadline for applications is the 21st of January. Click here for more details of this PhD opportunity.
A new paper, led by my colleague Callum McLean at Manchester Metropolitan University, has recently been published. The study investigates shape complexity in the pedipalps (mouthparts) of whip spiders within and across species using elliptical Fourier analysis. Pedipalps are used for hunting, but also used in contest for mates. The paper has several implications, but a key finding is that there may be a trade-off between investment in pedipalp length (for use in sexual selection / contest) v.s. spine length (for use in prey capture). You can read more about it in the (open access) paper, which is linked below:
McLean, C., Garwood, R.J. and Brassey, C. 2021. Assessing the patterns and drivers of shape complexity in the amblypygid pedipalp using elliptical Fourier analysis. Ecology and Evolution. doi: 10.1002/ece3.7882
A new paper, led by Euan Furness, from Imperial, has just been published:
Furness, E.N., Garwood, R.J., Mannion, P. D. & Sutton, M.D. 2021. Productivity, niche availability, species richness and extinction risk: Untangling relationships using individual-based simulations. Ecology and Evolution doi: 10.1002/ece3.7730
This contribution uses the Palaeoware package REvoSim to investigate the impact of productivity on species richness. It shows that species richness scales with productivity – matching some of the predictions of an explanation for this pattern called the more individuals hypothesis. For example, rare species are more extinction prone, as MIH predicts. But, we show that species richness only scales with productivity when species can partition niche space – the relationship doesn't hold when niche partitioning is prevented through saturation. Thus even when neutral explanations do help us understand patterns, we suggest niche theory is also important to consider.
One of the preprints mentioned below has just been published in Proceedings B. Whilst fossils are key to understanding past life, their impact on phylogenetic reconstruction is hard to assess: in real organisms we lack a true evolutionary tree. In this study, led by my colleague Nicolás Mongiardino Koch, we use the Palaeoware package TREvoSim to generate trees and associated character data, benchmark these against empirical datasets, and then evaluate the impact of including fossils in phylogenies. We do so using an analytical pipeline summarised in the graphic below:
The outcome? We show that fossils – irrespective of the levels of missing data or inference method – improve the accuracy of phylogenetic inference, and induce the collapse of highly uncertain relationships that tend to be incorrectly resolved. In our study, tip-dated analyses outperform undated inference methods: we suggest that the age of fossils contains important information that aids phylogenetic analyses. You can learn more in the open access paper linked below:
Mongiardino Koch, N., Garwood, R.J. & Parry, L.A. 2021. Fossils improve phylogenetic analyses of morphological characters. Proceedings of the Royal Society B: 288(1950):20210044. doi: 10.1098/rspb.2021.0044
A few new pieces of work that I've been lucky enough to contribute to have appeared since I last updated this website. The paper linked below, led by Imperial PhD student Euan Furness, uses the Palaeoware package REvoSim to investigate the impact of environmental disturbance on species richness. It shows that a key consideration is the scale of a disturbance, and the spatial heterogeneity of the environment. In a hetrogenous environment, small scale disturbance leads to a decrease in species richniess, but in a homoegeneous one, it increases species richness. In contrast, large scale disurbances always reduce the number of species. You can read more in the open access paper below:
Furness E.N., Garwood R.J., Mannion P.D. & Sutton M.D. 2021. Evolutionary simulations clarify and reconcile biodiversity-disturbance models. Proceedings of the Royal Society B: 288(1949):20210240. doi: 10.1098/rspb.2021.0240
A paper on smell in the sea catfish – for which I assisted with data collection – has also been published in recent weeks:
Cox, M.A., Garwood, R.J., Behnsen, J., Hunt, J.N., Dalby, L.J., Martin, G.S., Maclaine, J.S., Wang, Z. & Cox, J.P. 2021. Olfactory flow in the sea catfish, Ariopsis felis (L.): Origin, regulation, and resampling. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology p.110933. doi: 10.1016/j.cbpa.2021.110933
It's been a long since the last update of this site, in large part because of the COVID19 pandemic. This coincided with a relaunch of the degrees in the Department of Earth and Environmental Sciences. As a result I spent my time since June writing 1.5 course units for the first time, and then delivering them remotely. You can find the results at the two websites linked below:
The first of these sites (EART22101) has seven websites combining videos, quizzes, and other learning materials on topics surrounding evolution, and ancient life. The second (EART27201) has eight sites that focus on invertebrate macrofossils, and include 3D fossil models and the occasional virtual microscope. Materials are generally CC-BY and sources are always provided: they are available here in the hope that they are useful! There are other elements of course delivery provided through Blackboard (more quizzes, achievements to unlock) and via Zoom, which aren't included. Nevertheless, I hope they may be useful!
Early in lockdown, though, there was time for some science – and one of the results is a preprint which has just appeared on bioRxiv. You can find it by clicking on the link below:
In this paper, led by my colleague Nicolás Mongiardino Koch, we asses the impact of adding fossils to phylognies using a simulation based approach, based on the Palaeoware package TREvoSim. We demonstrate that adding extinct species always improves the accuracy of a phylogenetic analysis, even in the presence of missing data. We also show that tip-dated phloygenies – i.e. those which simultaneously infer tree topology and divergence times – outperform all other methods of inference. You can find out more by reading the freely available preprint!
A new paper, led by my colleague Jonathan Cox at the University of Bath, and a follow up to a paper released last year, has just appeared. This one uses CT scanning and CFD to study smell in the pike Esox lucius. As with the last such paper, although I am first author, this reflects authorship conventions in the field. I didn't lead the work, but did have the pleasure of conducting CT data collection. Details of this publication are as follows:
Garwood, R.J., Behnsen, J., Ramsey, A.T., Haysom, H.K., Dalby, L.J., Quilter, S.K., Maclaine, J.S., Wang, Z. & Cox, J.P.* 2020. The functional nasal anatomy of the pike, Esox lucius L. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 244: 110688. doi:10.1016/j.cbpa.2020.110688 (* = corresponding author)
I am pleased to report that a new paper has just appeared, accompanied by two new Palaeoware evolutionary simulation software packages. The paper is:
Keating, J.N., Sansom, R.S.*, Sutton, M.D., Knight, C.G. & Garwood, R.J.* In press. Morphological phylogenetics evaluated using novel evolutionary simulations. Systematic Biology doi:10.1093/sysbio/syaa012 (* = corresponding author)
In it, my colleagues and I use two new evolutionary models to test methods of inferring evolutionary trees. We use the models to simultaneously generate trees and discrete character data, one in a stochastic manner, and one using an individual-based approach which includes selection. We use different approaches to infer trees from the character data, and then comparing how the approaches perform by measuring the distance between the true and inferred trees. There have been a number of recent works that have taken a simulation approach, generating stoachastic data onto a set tree topology, which have generally suggested that Bayesian inference outperforms parsimony. Our study supports this idea, but also suggests this is because of the differences in search strategy and consensus methods used by each, rather than resulting from the optimality criterion they use. Our approach also allows us to demonstrate that stochastic- and selection-generated data behave differently, and that the amount of homoplasy in our datasets are not a good indicator of how methods of inference will perform. Rather morphological coherence (how strongly linked characters differences are to the evolutionary, or branch length distances between taxon paris) is a key consideration, and this is a bigger problem for selection-generated data. Morphology is thought to evolve through selection, and so we suggest that asking whether parsimony or Bayesian is better may not be the best appraoch for the field in future: both methods struggle with selection data. Rather if we can future research on modes of morphological evolution, and then use those to build models for probabilistic inference, we will do a better job of reconstructing trees in the future.
You can find releases of the two software packages/models we created for this paper by clicking the banner below. TREvoSim is our selection-based model. It uses a similar fitness-algorith to REvoSim, but employs a different species concept, does not include sexual reproduction, eschews space, and has variable genome sizes. MBL2017 is a birth-death model, which simulates lineage splitting and extinction, as well as character evolution, in a stochastic manner. Both packages are available as binaries for Windows and Mac OS, and can be built on Linux systems using four lines of bash. We are releasing the two in the hope that they are versatile and useful tools for the community, and would very much welcome feedback, bug reports, and feature requests: these are best achieved using the issues system in GitHiub, or by emailing us at email@example.com.
A new paper, led by my colleague Callum McLean, and in collaboration with Charlotte Brassey, both at Manchester Metropolitan University, has just been published. This reports sexual dimorphism within whip scorpion. These arachnids have spined limbs used to capture prey, but we show that they have also adapted through display contests which are used between males prior to mating in the species. An example of the species studied – Damon variegatus – is shown below (photo copyright Steve Smith).
McLean, C., Garwood, R.J. & Brassey, C. In press. Sexual dimorphism in the size and shape of the raptorial pedipalps of Giant Whip Spiders (Arachnida: Amblypygi). Journal of Zoology. doi:10.1111/jzo.12726
Two papers I've been involved with were published this week. The first is a review paper of the Rhynie Chert – a rock deposit in the north of Scotland which preserves an early terrestrial (land-based) ecosystem in unusually good detail. It represents A ~411 million-year-old hydrothermal system a bit like today's Yellowstone National Park in the USA. Hot water flooded patches of land in a valley within a mountainous area, killing the animals and plants before entombing them in a transluscent chert (a silica-based rock). This preserved the life that was around on land at this time – long before the earliest vertebrates made it from the sea into this new environment – in exquisite detail, sometimes down to a cellular level. The was discovered a century ago, and provides unique insights to early life on land. This paper, in the Geological Magazine, provides an overview of the history of the study of the deposit, its geology, how the fossils were preserved, and the plants, animals and other organisms that have been discovered at the site. The paper was written in collaboration with my colleagues Alan Spencer at Imperial College, and Heather Oliver, a masters graduate from the Department of Earth and Environmental Sciences at the University of Manchester. We hope it provides a useful overview, please do get in touch if you are unable to access a copy at the below link:
Garwood, R.J., Oliver, H. & Spencer, A.R.T. In press. An introduction to the Rhynie chert. The Geological Magazine doi: 10.1017/S0016756819000670
The second paper was led by my colleague Matthew Warke, who is currently at the St Andrews, which fousses on the form and trace element variation of ~2.5 Ga stromatolites, a time of global change shortly after oxygen first appeared in Earth's atmosphere. More details are at the link below:
Warke, M., Edwards, N., Wogelius, R.A., Manning, P., Bergmann, U., Egerton, V., Kimball, K., Garwood, R.J., Beukes, N.J. & Schröder, S. 2019. Decimeter-scale mapping of carbonate-controlled trace element distribution in Neoarchean cuspate stromatolites. Geochimica et Cosmochimica Acta 261: 56-75. doi: 10.1016/j.gca.2019.07.004
A paper conceived and led by my colleague Jonathan Cox at the University of Bath, has just appeared. This study uses CT scanning, 3D printing and computational fluid dynamics to study the mechanism my which stugeon smell. Although I am listed as first author this reflects authorship conventions in the field – I had the pleasure of conducting the CT data collection for the paper, rather than leading the work as being first might imply. Please do check it out:
Garwood, R.J., Behnsen, J., Haysom, H.K., Hunt, J.N., Dalby, L.J., Quilter, S.K., Maclaine, J.S. & Cox, J.P. 2019. Olfactory flow in the sturgeon is externally driven. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. In press. doi: 10.1016/j.cbpa.2019.06.013
A new paper which I was lucky enough to contribute to has just been published — it reports new species of spiders from the Jurassic of China, and places these in a phylogeny.
Selden, P.A., Huang, D. & Garwood, R.J. In press. New spiders (Araneae: Palpimanoidea) from the Jurassic Yanliao Biota of China Journal of Systematic Palaeontology, doi: 10.1080/14772019.2019.1584831
I'm very pleased to report that after a decade in development – off and on – my colleagues Mark Sutton, Alan Spencer, and I have published a paper documenting a model for simulating evolution, and a software implementation of this. The program is called REvoSim. The software employs digital organisms, and incorporates spatial relationships, spatial and temporal environmental variation, and recombinant reproduction. The software is highly efficient, and thus can simulate evolution over long time scales, with large population numbers. As such, it can model macro- as well as microevolution: for example, isolation of gene-pools (i.e. speciation) emerges naturally from simulations under appropriate conditions. We're releasing it in the hope that it can act as a multipurpose platform for the study of many evolutionary phenomena; while it was designed with macroevolutionary studies in mind, it is also applicable to microevolutionary problems. A full description of the model is available in the paper, published in the journal Palaeontology:
Garwood, R.J., Spencer, A.R.T. & Sutton, M.D. In press. REvoSim: Organism-level simulation of macro- and microevolution. Palaeontology. doi:10.1111/pala.12420
In order to release the source code for this, and other software, we have also created a GitHub organisation called Palaeoware. This hosts the code, and features Windows and Mac builds for the software, as well as simple instructions for Linux. The package also comprises a utility program called EnviroGen for creating REvoSim environments. More information is available on the Palaeoware GitHub REvoSim repository, and documentation is available through ReadTheDocs. A release candidate for v3.0.0 of the tomographic reconstruction software SPIERS has also been released recently in a Palaeoware GitHub repository.
Several further software packages are currently in development. Please do follow Palaeoware on twitter for updates.
I'm pleased to report that a new paper has appeared, led by colleagues in Material Sciences at the University of Manchester. In it the team, which I was fortunate enough to be a member of, use very high resolution CT scanning to understand how cracks grow in the exoskeleton of arthropods (in this case a beetle), and how the microstructure slows this process. The publication details, and a graphical abstract, are below.
Sykes, D., Hartwell, R., Bradley, R.S., Burnett, T.L., Hornberger, B., Garwood, R.J. & Withers, P.J. 2019. Time-lapse three-dimensional imaging of crack propagation in beetle cuticle. Acta Biomaterialia 86: 109-116. doi: 10.1016/j.actbio.2019.01.031
Interesting times are afoot when it comes to how we try and work out the evolutionary relationships between living groups of organisms. I've written an overview of what is happening for Palaeontology [online]. This explains how we build evolutionary trees, and how this has changed, and is changing now. Please do check it out.
Garwood, R. J. 2018. Patterns in Palaeontology – Deducing the tree of life. Palaeontology Online 8(12):1-10.
It's been a couple of months since I updated my website. In this time, two papers to which I have contributed have been published. The first assess the potential impact of neutron tomography – which we tried at the beamline IMAT – for studying fossils and other life sciences samples:
Burca, G., Nagella, S., Clark, T., Tasev, D., Rahman, I.A., Garwood, R.J., Spencer, A.R.T., Turner, M.J. & Kelleher, J.F. In press. Exploring the potential of neutron imaging for life sciences on IMAT. Journal of microscopy. doi:10.1111/jmi.12761
The second paper is one led by Callum McLean, who has previously completed an MPhil at the University of Manchester, and is now a PhD student at Manchester Metropolitan University. It provides an overview of sexual dimorphism within the arachnids:
McLean C.J., Garwood R.J. & Brassey C.A. 2018. Sexual dimorphism in the Arachnid orders. PeerJ 6:e5751 doi:10.7717/peerj.575
It's been a great pleasure to be involved in both these studies and to work with such talented colleagues. Also since my last update, two PhD projects supervised, or co-supervised, by myself have been advertised as part of the University of Manchester BBSRC Doctoral Training Partnership. Further details are available via the links below:
Please do email me if you are interested in either.
I recently had the pleasure of collaborating on a paper with two of my colleagues from the School of Earth and Environmental Sciences at the Uniersity of Manchester. In it we report the chemistry and structure (using tomography) of some 492 million-year-old, chrome-rich rocks from Shetland, which are also have high concentrations of platinum and palladium. The paper has now appeared in print, details below:
O’Driscoll, B., Garwood, R. J., Day, J. M. D. and Wogelius, R. 2018. Platinum-group element remobilisation and concentration in the Cliff chromitites of the Shetland Ophiolite Complex, Scotland. Mineralogical Magazine. 82(3): 471-490. doi:10.1180/minmag.2017.081.108
This is something else a bit different from my previous work – and also really interesting. Please do email me if you would like a copy.
A new paper I've been lucky enough to contribute to has just appeared, and it's a little bit different. For this publication my colleagues and I have filmed the leaps of jumping spiders in slow motion, and used the resulting videos to calculate the physics of their jumps. You can find more information about this work in the video below:
Details of the paper are as follows:
Nabawy, M. R., Sivalingam, G., Garwood, R.J., Crowther, W.J. and Sellers, W.I. 2018. Energy and time optimal trajectories in exploratory jumps of the spider Phidippus regius. Scientific reports, 8(1): 7142. doi: 10.1038/s41598-018-25227-9 (More information: 1, 2, 3, 4, 5, 6, 7).
I am pleased to report that a paper to which I contributed that describes a 127-million-year-old juvenile bird, has just been published. I got to play with a rather large synchrotron CT dataset for this paper, in which we showed that the baby bird’s sternum (breast bone) was still largely made of cartilage. This fills in a number of blanks regarding the development of this early group of birds. You can find an accessible introduction to the findings here. The full details of the publication, are as follows:
Knoll, F., Chiappe, L. M., Sanchez, S., Garwood, R. J., Edwards, N. P., Wogelius, R. A., Sellers, W. I., Manning, P. L., Ortega, F., Serrano, F. J. and Marugán-Lobón, J. 2018. A diminutive perinate European Enantiornithes reveals an asynchronous ossification pattern in early birds. Nature Communications, 9(1):937. doi:10.1038/s41467-018-03295-9 (More information: 1, 2, 3, 4).
In the summer of 2017 I was fortunate enough to contribute to the study of a remarkable fossil arachnid, which has just been published. The paper, led by Bo Wang of the Chinese Academy of Sciences, features a 100 million year old new arachnid species, Chimerarachne yingi. What makes this fossil quite remarkable is that it very spider-like (it even has spinnerets to spin silk), but retains a flagellum, or tail, at the back of the body. The survival of such a lineage, which must have split from the spider line more than 300 million years ago and then survived for a further 200 million, is totally unexpected. The full reference for the paper is as follows:
Wang, B., Dunlop, J. A., Selden, P. A., Garwood, R. J., Shear, W. A., Müller, P. & Lei, X-J. 2018. Cretaceous arachnid Chimerarachne yingi gen. et sp. nov. illuminates spider origins. Nature Ecology & Evolution. doi: 10.1038/s41559-017-0449-3 (More information: 1, 2, 3, 4, 5).
Here is a reconstruction of the fossil showing what it might have been like in life, with a link to the paper:
Towards the end of last year I gave two talks in quick succession on the research of several colleagues and myself on simulating evolution using custom built software:
Garwood R. J., Sutton, M. D., Knight, C., Gomez, G, Sansom, R. S., Keating, J. N. & Spencer, A. R. T. 2017. Simulating evolution in space and time. (Talk; Invited Speaker). Annual Meeting of the Palaeontological
Association, Imperial College, London.
Garwood R. J., Sutton, M. D., Knight, C., Gomez, G, Sansom, R. S., Keating, J. N. & Spencer, A. R. T. 2017. Modelling evolution in deep time. (Talk; Invited Speaker). Manchester Evolution Symposium.
My very talented friend and cartoonist DrJones of RatBot comics has kindly summarised these with the panel below, which I wanted to share:
You can find a wide range of other cool comics on her website. Also, the deadline for the PhDs available in palaeobiology topics (including those supervised by me, listed below) is in a couple of weeks. You can find more details about these, and other postgraduate, study opportunities here. Do get in touch if you are interested.
Earlier this year there was a meeting at the Royal Society, in London, titled The Rhynie Chert – our earliest terrestrial ecosystem revisited, organised by Professor Dianne Edwards CBE FRS, Professor Liam Dolan FRS and Dr Paul Kenrick. As part of this, I co-authored a talk, which went on to become a paper – that was released today:
Dunlop, J. & Garwood, R.J. 2018. Terrestrial invertebrates in the Rhynie chert ecosystem. Philosophical Transactions of the Royal Society B 373(1739): 20160493. doi: 10.1098/rstb.2016.0493
This is a review of the land-based animals from this fossil site, focussing in addition on the possible ecological strategies and interactions within this ecosystem. Please do email me if you would like a PDF.
Another paper to which I have contributed has just appeared. This one was led by Luke Parry, from the Royal Ontario Museum, and reports some trace fossils (burrows) more than 542 million years old. We have reconstructed these using CT (shown in the image below), and propose that they were created by some of the first organisms capable of moving through the sediment (leaving these sedimentary structures in the process). This is particularly of note because of their age – they are found in rock layers older than any known fossils of complex creatures like animals. DNA studies (which can be used to estimate how long ago a group originated) suggest the origin of animals may well date from before these burrows were formed. We suggest in the paper that the burrows – which are really small – are evidence that there were animals with muscle control around before their fossils appear in the fossil record, and the reason we have missed them to date is that they are so small. Hence the deepest splits in the animal tree may well have occurred in really small organisms living in sediments >550 million years ago. The full citation of the paper is below; do email me if you would like a copy.
Parry, L.A., Boggiani, P.C., Condon, D.J., Garwood, R.J., de M. Leme, J., McIlroy, D., Brasier, M.D., Trindade, R., Campanha, G.A.C. Pacheco, M.L.A.F., Diniz, C.Q.C, Liu, A.G. 2017. Ichnological evidence for meiofaunal bilaterians from the terminal Ediacaran and earliest Cambrian of Brazil. Nature Ecology and Evolution. In press. doi: 10.1038/s41559-017-0301-9
Also, I'm offering a number of PhD projects next year at the University of Manchester, if you would like to come and work with us here. Topics include:
If any of these sound of interest, please do get in touch. Full descriptions will be posted when available. You would be joining part a thriving cross-disciplinary research area at the University of Manchester. There are a large group of academic staff and associated researchers here addressing evolutionary and palaeobiology questions through studying ancient life. This is supported by Manchester’s Interdisciplinary Centre for Ancient Life and the Computational Biology group in the Evolution, Systems and Genomics Domain.
A new paper, led by Alan Spencer of Imperial College, has just been published. This work uses synchrotron tomography and digital visualisation (shown below) to investiages a ~143 million year old seed from the UK's Oxford Clay. The full details for the paper are as follows:
Spencer, A.R., Garwood, R.J., Rees, A.R., Raine, R.J., Rothwell, G.W., Hollingworth, N.T., & Hilton, J. 2017. New insights into Mesozoic cycad evolution: an exploration of anatomically preserved Cycadaceae seeds from the Jurassic Oxford Clay biota. PeerJ, 5, e3723. doi: 10.7717/peerj.3723
Four of the papers mentioned below have recently appeared in their final form, with the publication of Geological Society, London, Special Publication 448 – Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier. The fossils featured cover more than 3000 million years of life history, and multiple groups of organisms, from early potential bacteria, through to insects and dinosaurs in the relatively recent geological past. They represent the breadth of topics in which Martin Brasier — a very supportive colleague, with whom I had the great pleasure of working — was interested.
Brasier, A. T., Cotton, L. J., Garwood, R. J., Baker-Brian, J., Howlett, E. & Brasier, M. D. 2017. Earliest Cretaceous cocoons or plant seed structures from the Wealden Group, Hastings, UK. Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier. Geological Society, London, Special Publications. 448 (1): 399–411. doi: 10.1144/SP448.21
Brasier, M.D., Norman, D.B., Liu, A.G., Cotton, L.J., Hiscocks, J.E.H., Garwood, R.J., Antcliffe, J.B., & Wacey, D. 2017. Remarkable preservation of brain tissues in an Early Cretaceous iguanodontian dinosaur. Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier. Geological Society, London, Special Publications. 448 (1): 383–398. doi:10.1144/SP448.3 (More information: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11). [View]
Hickman-Lewis, K., Garwood, R.J., Withers, P., & Wacey , D. 2017. X-ray microtomography as a tool for investigating the petrological context of Precambrian cellular remains. Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier. Geological Society, London, Special Publications. 448 (1): 33–56. doi:10.1144/SP448.11
Wacey, D., Battison, L., Garwood, R.J, Hickman-Lewis, K., & Brasier, M.D. 2017. Advanced analytical techniques for studying the morphology and chemistry of Proterozoic microfossils. Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier. Geological Society, London, Special Publications. 448 (1): 81–104. doi:10.1144/SP448.4
Please do check them out, and — of course — email to request a PDF if one is not readily available.