Get access

Recent borings in limestone cobbles from Marloes Bay, southwest Wales

Authors

  • STEPHEN K. DONOVAN,

  • FIONA E. FEARNHEAD,

  • CHARLES J. UNDERWOOD


Stephen K. Donovan [donovan@naturalis.nl] and Fiona E. Fearnhead [fearnhead@naturalis.nl], Department of Geology, Nationaal Natuurhistorisch Museum, Postbus 9517, NL–2300 RA Leiden, The Netherlands; Fiona E. Fearnhead and Charles J. Underwood [c.underwood@bbk.ac.uk], School of Earth Sciences, Birkbeck College, University of London, Malet Street, Bloomsbury, London, WC1E 7HX, UK.

Abstract

Limestone clasts from the beach at Marloes Sands, southwest Wales, contain slender, straight to sinuous borings cross-cut by younger, clavate borings. The former were probably produced by sipunculids or polychaetes; the latter preserve shells of the boring bivalve Gastrochaena dubia (Pennant). Unusually, the calcareous linings of the clavate bivalve borings extend into many of the slender worm borings. Such linings are considered part of the hard parts of the producing bivalve, but the chance association of the two morphologies of borings has led to the lining becoming intimately associated with both of them. The modified linings of the bivalve borings have a similar morphology to the crypt of certain clavagellid bivalves, perhaps presenting an analogue for the morphology of a pre-clavagellid, boring ancestor.

Get access to the full text of this article

Ancillary