Janusiscus

Janusiscus schultzei is an extinct gnathostome vertebrate dating from the Early Devonian period in Siberia, approximately 415 million years ago. It may be a common ancestor of either Chondrichthyes (cartilaginous fish) or Osteichthyes (bony fish) or both or a sibling of their ancestor. If it is an ancestor to both types of fish, then "J. schultzei" would also be a common ancestor to all living jawed vertebrates. The species name is in honor of Hans-Peter Schultze; the genus named after Janus, the Roman god of duality.
Taxonomy.
The following cladogram is simplified from Giles "et al.", 2015: