Ostracoderm
/ˈɒstrəkəˌdɜːrm/noun
Any of the extinct jawless fishes that carried bony armour over the head and body.
The Greek roots
Literally: “shell skin”
The story of the word
Shell-skinned, and the shell came before the jaw: these fish wore heavy head shields in Ordovician and Silurian water while vertebrates still had no jaws and no teeth. Ὄστρακον is a potsherd, and it is the same word as the ballot of ostracism, where Athenians scratched a name on a broken piece of pot to send the man away for ten years. Thousands of the actual sherds have come out of the Kerameikos, including a batch bearing one name in a handful of hands, prepared in advance for voters who could not write.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
In a sentence
The ostracoderms were filter feeders in armour, which is a strange combination to picture.
A slab of Silurian sandstone full of ostracoderm plates.