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Plants & CreaturesGreekEnglish

Agnathan

/ˈæɡnəθən/noun

A jawless vertebrate, a group now reduced to the lampreys and hagfish.

The Greek roots

ἀ-
a-
not, without
+
γνάθος
gnáthos
jaw

Literally: jawless

The story of the word

Jawlessness is the older condition, not a defect: the first vertebrates had no jaws at all, and the ones that did came later, apparently by rebuilding a front pair of gill arches. Two lineages of agnathans survive, both of them slippery and unloved, against tens of thousands of jawed fish species. γνάθος also gives prognathous, jutting-jawed, a favourite word of nineteenth-century anthropometry.

How it travelled
Ancient Greek → scientific Latin → English

Same family

prognathousgnathostomechaetognath

In a sentence

The lamprey clamped to the salmon's flank is an agnathan doing what agnathans do.

Built on the same root

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