Kalmar "Genus Ichthyostega" tana nufin wani nau'in tetrapod maras kyau (kayan kasusuwa masu hannu huɗu) waɗanda suka rayu a zamanin Late Devonian, kusan shekaru miliyan 358-340 da suka wuce. Sunan "Ichthyostega" yana nufin "rufin kifi," kuma yana nufin gaskiyar cewa wannan dabba yana da lebur, faranti na kasusuwa a bayanta, kama da wanda aka samu akan wasu kifi. Yana daya daga cikin sanannun tetrapods kuma an yi imanin cewa ya kasance muhimmiyar hanyar haɗi a juyin juyin halitta daga kifi zuwa masu amphibians.