A fossil record of lampreys has previously been unknown. A new genus demonstrates the presence of this group in the Pennsylvanian. The body outline, parts of the head skeleton, rasping tongue mechanism, gill basket, and other internal organs are preserved. The fossils are very similar in structure to modern forms. The absence of hagfish characters in the fossil supports the view that the common ancestor of lampreys and hagfishes lived prior to the Pennsylvanian.
A fossil hagfish (Myxinoidea), a new genus from the Pennsylvanian, shows tentacles, structures of the head skeleton and internal organs. No other fossils of this group have been reported. Although this new hagfish differs from living forms in position of the gills, feeding apparatus, and relatively well developed eyes, it is quite similar to its recent relatives. Thus, hagfishes have a long, conservative geological history. Cladograms showing myxinoids as a sister group to the vertebrates are supported.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.