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Brachiopods are sea shells made of two valves, usually anchored to the sea floor by a
stalk, or pedicle. The pedicle is attached to the inside of the brachial valve and exits
through an opening in the pedicle valve - the two valves are therefore
different in size, although they show bilateral symmetry.
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They feed by opening the valves and filtering food particles from the sea water, wafted
into the open valves by a tongue-like lophophore, which extracts oxygen from the water. The lophophore may be
supported by various forms of a calcite ribbon-like structure called the brachidium.
Brachiopods were very common during the Palaeozoic but declined in numbers during the Mesozoic. They are rarely
found today, mostly in brackish or inter-tidal waters.
Geopix Study Guide "Brachiopods"
- gives an illustrated description of brachiopods;
- describes the main morphological features;
- explains how the mode of life is related to the shape of the shell.
The Study Guide contains the following pages:
'Brachiopods' is part of the Geopix Fossils Study Guide CD.
To order this CD go to the Geopix Online Store
