Janusiscus schultzei was a Gnathostomata (jawed 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. 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.