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The Fauna and Flora of the Rhaetian of South Wales and Adiacent Areas Derek Ager and Dianne Edwards Professor Thomas Maxwell Harris died on May 1st 1983 at the age of 80. Although best known for his definitive and monumental work on fossil plants from the Mesozoic of Greenland and Britain, including the Rhaetian of South Wales, as natural historian, gardener, chef, wine-maker and experimenter he was also passionately interested in living plants. His wit, clarity of expression and command of the English language in his lectures, conversation and prose were a constant delight. Prossessed of that rare gift of regenerating his own excitement and enthusiasm in others he was totally unselfish with his immense store of knowledge and was the most stimulating, demanding, forthright and, on occasions, intimidating of mentors. His energy and physical stamina were tremendous: when head of the Botany department at the University of Reading, University teacher as well as holder of a number of high offices in learned societies he remained an active researcher, a hunter-gatherer of basic data which were recorded in copious sprawling notes and meticulous drawings. He was firm in his belief that the camera was the tool of the lazy man. He continued his research into his retirement and shortly before his death, wrote notes on some new Clathropteris specimens from the Rhaetian of South Wales. He was no stranger to the flora, having published an account of it about thirty years earlier. Here we reproduce his ms. description of the new material both to save it from oblivion and to pay tribute to the most well-known and highly respected palaeobotanist of recent times. Fig. 1 Distribution of land and sea in southern Britain in late Triassic times. General Setting By the end of Triassic times what is now South Wales was already north of the tropical belt in its long journey northwards from the southern hemisphere (Fig. 1). Indeed, it had probably crossed the equator some 90 million years before, during the time when the Coal Measures swamps were forming in South Wales. Southern Britain had clearly passed into the desert belt of the northern hemisphere, like the Sahara today, with the trade winds constantly blowing from the east, in a world of dust storms, dune sands, stony deserts and ephemeral bodies of water in which salts of various kinds were deposited. The characteristic colour of Triassic deposits in northern Europe was the red of an oxidising desert and towards the end of the period red dust blew about the arid landscape to accumulate in great thickness as what is wrongly called the Keuper Marl. In the south of what is now the Vale of Glamorgan, limestone hills stood up through the red Triassic cover (Fig. 2). These were composed of early Carboniferous rocks, full of corals and other fossils indicating warm tropical seas that covered the area before the spread of the Coal Measures. These limestone hills were deeply weathered and showed many features of karstic scenery. Indeed, when the M4 motorway was being excavated near Cornelly, good karstic surfaces were briefly exposed. Towards the end of Triassic times, the climate Fig. 2 Suggested palaeogeography of the Vale of Glamorgan ir late Triassic times. Open stipple = upland areas which stood up above a desert plain covered by late Triassic deposits of the Mercia Mudstone Group. Close stipple = marginal lappings o the Rhaetian sea on to the upland areas and isolated inselberg: submerged by that sea. Based in part on T.N. George 1970, fig 34.