'anostracan' originates from New Latin 'Anostraca', ultimately from Greek elements 'an-' and 'ostrakon', where 'an-' meant 'without' and 'ostrakon' meant 'shell' or 'shell-like plate'.

'anostracan' changed from the New Latin taxonomic name 'Anostraca' (used for the order) into the English form 'anostracan' to denote an individual or adjective form; the New Latin name itself was formed from Greek roots.

Initially, the components literally indicated 'without a shell', but over time the term evolved to refer specifically to crustaceans of the order Anostraca rather than a literal description used in everyday speech.