Article · Wikipedia archive · Last revised Jun 13, 2026

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 and Osteichthyes. 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.

Last revised
Jun 13, 2026
Read time
≈ 1 min
Length
172 w
Citations
2
Source
Janusiscus
Temporal range:
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Infraphylum: Gnathostomata
Genus: Janusiscus
Giles et al., 2015
Species:
J. schultzei
Binomial name
Janusiscus schultzei
Giles et al., 2015

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) and 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

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)

References

References

External links