Cyclostomi, often referred to as Cyclostomata /sɪkloʊˈstɒmətə/, is a group of vertebrates that comprises the living jawless fishes: the lampreys and hagfishes. Both groups have jawless mouths with horny epidermal structures that function as teeth called ceratodontes, and branchial arches that are internally positioned instead of external as in the related jawed fishes. The name Cyclostomi means "round mouths". It was named by Joan Crockford-Beattie.
Temporal range: Lochkovian - Recent
|Sea lamprey from Sweden|