Conference Contribution Details
Mandatory Fields
MacGabhann, B.A. & Murray, J.
52nd Irish Geological Research Meeting.
New Paropsonemid Eldonids from southern Morocco.
Trinity College Dublin.
Oral Presentation
Optional Fields
20-FEB-09
22-FEB-09
The eldonioids are a poorly understood Lower Palaeozoic group of non-mineralised discoidal fossils, the best known of which is the enigmatic Eldonia ludwigi, described by Walcott from the Burgess Shale (Lower Cambrian, British Columbia). The group is characterised by the presence of a coiled sac, enclosing the digestive tract of the animal, a distinguishing feature which is unique, and easily identifiable. The paropsonemids are an even more poorly known clade within the eldonioids, occasionally mistakenly identified as chondrophorines (‘by the wind sailors’). These forms are distinguished by a complex ornamentation consisting of one or more orders of radial rays interconnected by fine pitted structures. A newly discovered site in southern Morocco has yielded 30 specimens of a new paropsonemid eldonioid, preserved as moulds and casts within a single sand bed of upper Ordovician age. The fossils preserve the ornamentation in fine detail, and show the integument to have been flexible. Preservation at different levels within the bed confirms the fossils to have been transported, however they all appear to be preserved with the same surface facing downwards, suggesting an element of their morphology or their environment may have exerted an overriding control on their preserved orientation.
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