Alwyn Williams died peacefully of cancer on 4th April at Glasgow, aged 82.

This obituary was posted by Norman McLeod of the Natural History Museum.

He was a giant amongst brachiopod workers, being not only the editor and first author of the first brachiopod Treatise on Invertebrate Palaeontology (two volumes) in 1965, but fulfilled the same roles in the second edition: four volumes of which have been published (1997 to 2003), and there are another two in press. He successfully organised contributions from 43 co-authors for the second edition, an enormous political challenge which he tackled with a characteristic mixture of charm, terror and efficiency.

But the originality of his brachiopod work was also outstanding; he was the first to evaluate shell structure across the whole phylum through pioneer electron microscopy; he was amongst the first to undertake DNA studies; over his long career he published and refined many times the overall classification of the Brachiopoda, with the end product of a robust and well-known phylogeny that will probably require little future change.

His systematic work, although originally on Silurian faunas (he was the first to recognise and document the evolution of Stricklandia, a key zonal fossil) was chiefly concerned with the Ordovician. His substantial and painstaking memoirs and monographs on the Ordovician brachiopods of central and northern Wales, Shropshire, and Girvan, as well as many smaller papers, will stand for a long time. For many of these areas he also remapped the often difficult geology, and published correlation data. He was the lead author of the 1973 Ordovician correlation chart of Britain and Ireland, and the first Chairman of the IUGS Ordovician Subcommission. He had many prizes, including the Murchison Medal of The Geological Society of London, and was a Fellow of the Royal Society. He was also knighted.

He was head of the Geology Department at Queen's University, Belfast, for nearly 20 years, then moved on to be Head of Geology at Birmingham in 1973, from which he went to become Principal of Glasgow University, a job that for any normal person would have meant the cessation of geological research. Alwyn was not a normal person. He will be much missed.

He is survived by his widow, Joan, was also a student at Aberystwyth, and son and daughter Gareth and Sian.

The following appeared on the occasion of his award of the Lapworth Medal by the Palaeontological Association:

The President's citation: Alwyn Williams has been described as one of the great geologists of the second half of the 20th century. His name is associated with two palaeontological fundamentals: brachiopods and the Ordovician, but he always has been a major innovator. He mapped large areas of Palaeozoic rocks in SW Scotland, Wales and the west of Ireland. He introduced and applied biometric methods to the taxonomy of brachiopods (using a hand-held calculator even in the 1950s-a black cylinder with a rotating handle on the top!). He combined statistical methods and phylogeny to produce a landmark series of palaeogeographic maps for the Ordovician Period. He pioneered the investigation of brachiopod shell structure and its application to their classification using the scanning electron microscope, and he has been the major player in the production of the brachiopod volumes of the Treatise on Invertebrate Paleontology.

After completing his PhD at the University of Wales (Aberystwyth) on the classic Liandeilo district, Alwyn Williams spent two years (1948-50) in Washington as a Harkness Fellow. This was the start of a long term friendship with G. Arthur Cooper, doyen of N. American brachiopod workers, and an opportunity to study the remarkable collections in the Smithsonian. Before going to Washington Alwyn had already started work on the Ordovician rocks of the Girvan district. The brachiopods there revealed remarkable similarities to the faunas that Cooper was describing from the Appalachians (a decade before plate tectonics).

In 1950 Alwyn moved to Glasgow, as Lecturer in Geology, where he regarded teaching as no less important than research. A former student reported that his laboratory classes presented students with their first opportunity to handle fossils rather than peer at them through glass cases! Four years later, in his early thirties, Alwyn was appointed Professor of Geology at Queen's University of Belfast, where he spent the next 20 years. There he published groundbreaking papers on brachiopod taxonomy and phylogeny, growth and shell structure (with the establishment of an SEM facility), and on palaeobiogeography and stratigraphy, including the 1972 Geological Society Special Report 3 on the Correlatian of Ordovician rocks in the British Isles. Alwyn's enthusiasm for teaching was legendary; long Easter Vacation days in the field at Girvan, followed by evening seminars timed to end for last orders in the nearest bar. In 1967 he was elected FRS and he was president of the Palaeontological Association in 1968-69, hosting the annual conference in Belfast the following year.

Alwyn Williams enjoyed a long association with Professor Harry Whittington FRS, first recipient of the Lapworth Medal. Harry tells me that one summer in the late 1950s he and his wife Dorothy were in Bala collecting while Douglas Bassett was mapping. Alwyn arrived by train, a one-carriage steam engine from Bala junction. Harry and party laid out a strip of red carpet, he and Doug Bassett held geological hammers aloft in a ceremonial arch and Harry's mother presented Sir Alwyn with a bunch of Welsh leeks. This most articulate of men was for once apparently lost for words!

A brief period as Lapworth Professor in Birmingham was followed by Alwyn's appointment in 1976 as Principal and Vice Chancellor of the University of Glasgow. Despite his administrative commitments, he published some 20 refereed papers (and held three NERC grants) while running the University. It was rumoured that in some years he published more than entire Glasgow departments. Since his retirement in 1988 Alwyn has been a cornerstone of the Palaeobiology Unit at Glasgow. He has published a steady stream of important papers on brachiopods and he has seen four volumes of the revised Treatise published as coordinator and chief editor

Professor Sir Alwyn Williams is an outstanding scientist and administrator. It is a great pleasure to present him with the Lapworth Medal of the Palaeontological Association.

Sir Alwyn replied:

Receiving any medal from a Learned Society is always a privilege but this one is special because it really honours Charles Lapworth to whom I am indebted socially and geologically. As an Ordovices on my father's side, I am indebted to Lapworth for immortalizing the tribal name. As part Silures on my mother's side, I am grateful to him for settling a family territorial dispute in such style-even if we have to go to Scotland to see where the boundary is drawn. And then there is the Girvan area and the Stinchar Valley, which for a decade or so assuaged my nostalgia for Appalachian geology so vividly revealed to me by Arthur Cooper.

Speeches of thanks for Medals seldom vary in format which is basically a list of colleagues who have contributed to winning the award because no research of consequence is done without support from others. My problem was, therefore, the familiar headache of selecting from among my mentors, collaborators, research assistants and postgraduates those to whom I'm especially indebted without overlooking others who have always been there, like my wife, Joan, who can still smile indulgently in this 53rd year of daily halelluliahs to the Brachiopoda. So I hope I'm forgiven for naming just some palaeontologists who have published papers with me, especially in the Association's Journal.

Before and during my lapse into the heresy of Administration, they included the evergreen Tony Wright, Bert Rowell, Sarah Mackay, Gordon Curry and Martin Lockley who deserted brachiopods for dinosaurs. I don't know why; walking with brachiopods is much more acrobatic! Since becoming a born-again Palaeontologist my world of collaboration has known no bounds. In the company of the unflappable Howard Brunton and 40 or so other authors from 15 countries, the brachiopod Treatise has been undergoing a revision for the past 14 years. With four volumes published and two more to go, contributors can all look forward to the end of the affair by 2006.

On the side and greatly facilitated by the Electronic Revolution, I've enjoyed research with sharpminded colleagues like Lars Holmer, Leonid Popov, Sandy Carlson, Dave Harper, Bernie Cohen, Carsten Luter and, above all, Maggie Cusack who has patiently tried to take my familiarity with biochemistry a little beyond the digestion of my next meal.

Finally, despite my promise to limit my thanks to co-authors in Palaeontology, there is one whom I have known for 50 years since first we worked together strictly as stratigraphers. He is, Harry Whittington, the first recipient of this Medal. For over ten years, mostly with Doug Bassett, we worked in Adam Sedgwick's fiefdom of Bala, mapping rocks identified as Sedgwick's Upper Cambrian or Murchison's Lower Silurian-the raison d'etre for Lapworth's Ordovician.

Those were golden days, albeit draped in veils of rain. Harry's wife Dorothy drove us to field sites in their armoured truck of a Volvo. One such site was the quarry at Gelli-grin, known to Sedgwick and M'Coy, and almost certainly visited and sat in by Charles Darwin the summer he acted as Sedgwick's field assistant. We took turns in sitting on a damp, cold, mossy block of ash in the hope of absorbing any lingering vibrations of Darwinian wisdom. I didn't, but I do now know what Darwin's mysterious illness was in his later life!

You younger palaeontologists are, of course, experiencing the same scientific excitement and good companionship as we did then. Cherish those memories, they will serve you well in old age!