Shokawa

Shokawa is an extinct genus of choristoderan diapsid reptile, known from the Lower Cretaceous of Japan. It is only known from one species, Shokawa ikoi. The only known remains are a postcranial specimen lacking the skull, discovered at the KO2 locality in sediments belonging to the Okurodani Formation near the village of Shokawa in Gifu Prefecture. Shokawa possessed a long neck with at least 16 cervical vertebrae, and closely resembles and is closely related to the smaller choristoderan, Hyphalosaurus.^[1][2] The generic name refers to the village near where it was found, while the specific name honors the collector of the first specimen, one Mr. Ikoi Shibata.

Shokawa Temporal range: Early Cretaceous, Berriasian PreꞒ Ꞓ O S D C P T J K Pg N
Artist's reconstruction
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	†Choristodera
Family:	†Hyphalosauridae
Genus:	†Shokawa Evans & Manabe, 1998
Type species
†Shokawa ikoi Evans & Manabe, 1998

Phylogeny from the analysis of Dong and colleagues (2020):^[3]

Choristodera

Cteniogenys sp. Heishanosaurus pygmaeus Coeruleodraco jurassicus Neochoristodera Ikechosaurus pijiagouensis Ikechosaurus sunailinae Tchoiria namsari Tchoiria klauseni Champsosaurus C. gigas C. albertensis Simoedosaurus S. lemoinei S. dakotensis "Allochoristodera" Monjurosuchus splendens Philydrosaurus P. proseilus P. proseilus Lazarussuchus L. inexpectatus Lazarussuchus sp. L. dvoraki Khurendukhosaurus orlovi Hyphalosaurus sp. Hyphalosaurus lingyuanensis Shokawa ikoi

References

1. Evans, Susan E.; Manabe, Makoto (January 1999). "A choristoderan reptile from the Lower Cretaceous of Japan". Special Papers in Palaeontology.
2. The dentary of a Choristodere (Reptilia: Archosauromorpha) from the Okurodani Formation, Tetori Group (Lower Cretaceous) of Japan
3. Dong, Liping; Matsumoto, Ryoko; Kusuhashi, Nao; Wang, Yuanqing; Wang, Yuan; Evans, Susan E. (2020-08-02). "A new choristodere (Reptilia: Choristodera) from an Aptian–Albian coal deposit in China". Journal of Systematic Palaeontology. 18 (15): 1223–1242. Bibcode:2020JSPal..18.1223D. doi:10.1080/14772019.2020.1749147. ISSN 1477-2019. S2CID 219047160.