Brachiopod
/ˈbrakɪəpɒd/noun
A marine invertebrate with two unequal shells, anchored to the seabed by a fleshy stalk and feeding by a ciliated coiled organ.
The Greek roots
Literally: “arm-foot”
The story of the word
The name records a mistake. Early naturalists took the coiled feeding organ inside the shell for arms doing the work of a mollusc's foot, and the arms are real enough but the analogy is not. Brachiopods dominated the Palaeozoic seafloor, then lost almost everything in the end-Permian extinction and never recovered; the bivalves you find on a beach today are a different phylum wearing a similar coat. Their shells hinge top to bottom, not left to right, which is the fastest way to tell them apart.
- How it travelled
- Ancient Greek → scientific Latin → English
- First recorded
- 19th century
Same family
In a sentence
The limestone is packed with brachiopod shells the size of a thumbnail.
Only a few hundred brachiopod species survive today.