Brachiopods

Brachiopods Mucrospirifer thedfordensis from the Devonian of Ontario, Canada. Source: Museum Victoria.

These animals live on the bottom of the ocean. Their soft parts are enclosed in a two-valved shell, which is joined by a hinge.

They are sometimes called lamp-shells because they look like old-fashioned oil lamps (the sort that Aladdin had!). Most attach themselves to the sea floor by a single stalk (or pedicle) which extends from their shell and allows the animal to orient itself in the current.

They feed by drawing water into their shell and filtering out food particles.

Assemblage of brachiopods Archaeorthis waratahensis from the Lower Ordovician of Waratah Bay, South Gippsland, Victoria. Source: Museum Victoria.

Brachiopods were once very common, but are rarer now-there are 12000 fossil species known, but only 300 species still living today (some in Westernport Bay). The first Brachiopods arose in the Cambrian Period (490 to 545 million years ago) and various fossil species are often used to date rocks, especially in the Carboniferous and Permian periods (354 to 251 million years ago).

Fossil brachiopods are found in many places in Australia-some recent fossils are found near the sea, such as at Jan Juc near Torquay (Victoria), while others are found far inland and are evidence of ancient seas (for example, at Lilydale, Kinglake and Buchan in Victoria, and near Yass in NSW).