Teredo Wood

Petrified wood with boreholes of shipworm.

In petrified wood the original organic material has been replaced by quartz (chalcedony or agate) but sometimes by other minerals like opal, pyrite, calcite and others.

Origin of name: after the naval shipworm Teredo navalis

Localities: Cannonball Formation, Morton County, North Dakota

Worth knowing: despite its wormlike appearance Teredo navalis is a bivalved clam. The shells, reduced in size, so that they cover only the foremost part of the molluscs soft body, function as boring tools.

Originating in the northeast Atlantic Ocean Teredo navalis has spread around the world and is a major cause of damage and destruction to submarine timber structures and the hulls of wooden boats.