Definitions

1. noun

A genus of extinct placoderm fish, known from Devonian fossils in Europe and North America.

“The discovery of Semionotus fossils in the UK revealed a new understanding of ancient fish evolution.”

2. adjective

Related to or resembling Semionotus fish.

“The Semionotus-like features of the fossil were a key factor in its identification as a member of the genus.”