Anagnota

Anagnota refers to a group of jawless fish characterized by the absence of true jaws. The term is largely historical and rarely used in modern taxonomic classifications. These early vertebrates, ancestral to both lampreys and hagfish, possessed a circular, sucking mouth, but lacked the hinged jaws found in gnathostomes (jawed vertebrates). The term distinguishes them from Gnathostomata, encompassing all vertebrates with jaws.

Historically, Anagnota was used to classify the Agnatha, a superclass within the phylum Chordata. Agnatha literally means "without jaws." However, modern phylogenetic analyses have shown that the Agnatha, as traditionally defined, are paraphyletic, meaning they do not include all descendants of a common ancestor. Therefore, the term Anagnota, associated with this older classification scheme, is now largely obsolete in scientific discourse. Modern classifications typically focus on clades like Cyclostomata (lampreys and hagfish) and the extinct ostracoderms to understand the evolutionary relationships of jawless vertebrates. While no longer a primary classification term, Anagnota remains useful in historical context when discussing older evolutionary hypotheses.