Continuing the theme of pebbles with holes made by sea creatures, the photographs here show pebbles of soft sedimentary rock which bear, not only the larger sort of hole made by boring bivalved molluscs, but also many much smaller holes.
These small holes may be seen in some instances to occur in pairs that represent both openings of the U-shaped tunnel that has been dissolved into the stone by the presence of a mudtube-dwelling marine bristle worm or (polychaete) such as the ubiquitous Polydora ciliata (Johnston).
The tunnels in the rock can often be seen like narrow open channels on the surface. This happens in the pebbles that are old and in which the outer layer has been eroded away by mechanical damage.
Earlier posts on the burrowing damage caused by small marine mudtube-dwelling polychaetes can be found in Flat oyster shells with Polydora ciliata burrows and Ancient & modern Polydora ciliata type burrows in Flat Oyster shells.
Revision of a post first published 13 November 2009
COPYRIGHT JESSICA WINDER 2011
All Rights Reserved