Chironius diamantine. Photo credit: R. Santos
The Neotropical colubrid genus Chironius contains a monophyletic assemblage of snakes having very low (10 or 12) dorsal scale rows at midbody. Currently the genus includes 20 species of diurnal snakes distributed from Honduras south to Uruguay and northeastern Argentina. Recently, a lectotype was designated for Chironius flavolineatus, a widespread species in open formations of South America (particularly in the Cerrado and Caatinga), with records from Marajó island, northern Brazil. Chironius flavolineatus is distinguishable from other members of the genus by the presence of a conspicuous yellow vertebral stripe bordered anteriorly by black. In a new Zootaxa paper, Fernandes and Hamdan (2014) describe the 21st species of Chironius, C. diamantine which differs from other Chironius in the combination of its color pattern, 2-4 temporal scales, an entire anal plate, 6-10 rows of dorsal scales at midbody, and some other characters. The new species is known from municipalities of Morro do Chapéu, Rio de Contas, and Palmeiras in the Chapada Diamantina, Bahia, Brazil. All specimens were found between sea level 1000 m asl. One individual was observed foraging about 3:00 PM on the banks of a rocky river near a waterfall, a few minutes later plunged into the river and remained there for about two minutes.
Fernandes DS, & Hamdan B. 2014. A new species of Chironius Fitzinger, 1826 from the state of Bahia, Northeastern Brazil (Serpentes: Colubridae). Zootaxa, 3881(6), 563-575.