Chironius is a genus of New World colubrid snakes, commonly called sipos (from the Portuguese word cipó for liana), savanes, or sometimes vine snakes. There are 23 described species in this genus.

Species

The following 23 species are recognized as being valid.

• Chironius bicarinatus (Wied, 1820) – two-headed sipo

• Chironius brazili

• Chironius carinatus (Linnaeus, 1758) – Amazon coachwhip

• Chironius challenger Kok, 2010

• Chironius diamantina

• Chironius exoletus (Linnaeus, 1758) – Linnaeus's sipo

• Chironius flavolineatus (Boettger, 1885) – Boettger's sipo

• Chironius flavopictus

• Chironius foveatus Bailey, 1955 – South American sipo

• Chironius fuscus (Linnaeus, 1758) – brown sipo

• Chironius gouveai Entiauspe-Neto, Lúcio-Lyra, Koch, Marques-Quintela, Diesel-Abegg & Loebmann, 2020 – Gouvea's sipo

• Chironius grandisquamis (W. Peters, 1869) – Ecuador sipo

• Chironius laevicollis (Wied, 1824) – Brazilian sipo

• Chironius laurenti Dixon, Wiest & Cei, 1993

• Chironius leucometapus – yellow-headed sipo

• Chironius maculoventris – central sipo

• Chironius monticola Roze, 1952 – mountain sipo

• Chironius multiventris Schmidt & Walker, 1943 – long-tailed machete savane

• Chironius quadricarinatus (F. Boie, 1827) – central sipo

• Chironius scurrulus (Wagler, 1824) – Wagler's sipo, smooth machete savane

• Chironius septentrionalis Dixon, Wiest & Cei, 1993 – South American sipo

• Chironius spixii

• Chironius vincenti (Boulenger, 1891) – St. Vincent blacksnake

Nota bene: A binomial authority in parentheses indicates that the species was originally described in a genus other than Chironius.

Conservation status

The St. Vincent Blacksnake, Chironius vincenti, is listed as critically endangered by the IUCN Red List due to its extremely limited range on the Island of St. Vincent.

References

Further reading

• Fitzinger LI (1826). Neue Classification der Reptilien nach ihren natürlichen Verwandtschaften. Nebst einer Verwandtschafts-tafel und einem Verzeichnisse der Reptilien-Sammlung des K. K. zoologischen Museum's zu Wien. Vienna: J.G. Heubner. five unnumbered + 67 pp. + one plate. (Chironius, new genus, p.60). (in German and Latin).

• Freiberg M (1982). Snakes of South America. Hong Kong: T.F.H. Publications. 189 pp. . (Chironius, pp.30, 64, 92).

• Torres-Carvajal O, Echevarría LY, Lobos SE, Kok PJR (2018). "Phylogeny, diversity and biogeography of Neotropical sipo snakes (Serpentes: Colubrinae: Chironius)". Molecular Phylogenetics and Evolution 130: 315–329.