Janusiscus

Janusiscus schultzei is an extinct gnathostome vertebrate dating from the Early Devonian period in Siberia, approximately 415 million years ago. It may be the sister group of the last common ancestor of Chondrichthyes (cartilaginous fish) or Osteichthyes (bony fish). This makes J. schultzei a sister species 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.^[1]

Janusiscus Temporal range: 415 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Infraphylum:	Gnathostomata
Genus:	†Janusiscus Giles et al., 2015
Species:	†J. schultzei
Binomial name
†Janusiscus schultzei Giles et al., 2015

Taxonomy

The following cladogram is simplified from Giles et al., 2015:^[1]

	†Galeaspida †Osteostraci Gnathostomata †Antiarchi †Petalichthyida †Ptyctodontida †Rhenanida †Arthrodira †Janusiscus schultzei Osteichthyes (Bony fish and tetrapods) †Acanthodii Chondrichthyes (Cartilaginous fish)