1 The shark-beds of the Eyam Limestone Formation (Lower Carboniferous, Viséan) of Steeplehouse Quarry, Wirksworth, Derbyshire, UK This paper is dedicated to the memory of Trevor Ford Roy Smith1*, David M. Martill2 and Christopher Duffin3 1 University of Portsmouth; email:
[email protected] 2 University of Portsmouth; email:
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[email protected] ABSTRACT The Eyam Limestone Formation of Steeplehouse Quarry, Wirksworth, Derbyshire, UK yields a diverse assemblage of Lower Carboniferous vertebrate remains. The assemblage is dominated by dermal denticles of the enigmatic selachian Petrodus patelliformis M’Coy, 1848, but also contains teeth of petalodonts, hybodonts and neoselachians. Actinopterygian remains also occur. The assemblage has yielded the earliest Neoselachian, Cooleyella fordi (Duffin and Ward, 1983) and the earliest British lonchidiid, Reesodus wirksworthensis (Duffin 1985). The first occurrence of the enigmatic spiny shark Acanthorhachis (Listracanthidae) is reported from the Viséan, extending its range back some 10 million years. Associated invertebrate remains and sedimentological data indicates a thriving fore-reef environment, deposited in a low energy off-reef setting. The vertebrate remains are well preserved with little abrasion, indicating short transport distances. Conodont elements indicating a late Brigantian age (Early Carboniferous, Viséan) have unusual and extensive euhedral apatite overgrowths. Key words: Early Carboniferous, Viséan, Vertebrates, Elasmobranchs, Conodonts, England 2 1. Introduction Isolated shark remains occur in remarkable abundance in a series of thin layers in the Eyam Limestone Formation at Steeplehouse quarry, near Wirksworth, Derbyshire. They were first noticed by Shirley (1958), but a more extensive study was presented by Ford (1964) who identified the remains as the dermal denticles of the enigmatic selachian Petrodus patelliformis M’Coy, 1848.