Chironius challenger KOK, 2010
Can you confirm these amateur observations of Chironius challenger?
|Higher Taxa||Colubridae, Colubrinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Chironius challenger KOK 2010|
Chironius fuscus — MÄGDEFRAU et al. 1991: 22
Chironius fuscus fuscus — DIXON et al. 1993: 114 (part.)
Chironius fuscus — MYERS & DONNELLY 2008: 121
Chironius challenger — WALLACH et al. 2014: 159
|Distribution||Guyana, E Venezuela|
Type locality: southeastern slope of Maringma Tepui, Cuyuni-Mazaruni District, Guyana (05° 12’ N, 060° 35’ W, 1500 m elevation.
|Types||Holotype: IRSNB 2659 (field number PK 2017), a subadult female collected by Philippe J. R. Kok, 25 November 2007 at 10h 45.|
|Diagnosis||Definition and diagnosis. A species of the genus Chironius characterized by the following combination of characters: 10 dorsal scale rows at midbody, absence of apical pits and paravertebral keels in female (male unknown), 152–159 ventrals, 99–103 subcaudals, anal plate single, loreal as long as—or slightly longer than—high, 39–41 maxillary teeth.|
Only five of the 20 currently known Chironius species occur in the Guiana Shield (area sensu Ávila-Pires 2005, number of species fide Hollis 2006): C. carinatus (Linnaeus, 1758), C. cochranae Hoge and Romano, 1969, C. exoletus (Linnaeus, 1758), C. fuscus (Linnaeus, 1758), and C. scurrulus (Wagler, 1824). Among these species, only C. fuscus and C. scurrulus have 10 DSR at midbody, a condition shared by C. challenger. All other species have 12 DSR at midbody.
Chironius challenger is readily distinguished from C. scurrulus by the following characters (characters of C. scurrulus in parentheses): absence of apical pits (present, at least on neck), loreal as high as long or only slightly longer than high (distinctly longer than high), juveniles brownish with lighter crossbands (uniform green in life, blue-black in preservative), adults brownish with lighter crossbands (red or reddish brown in life, colouration variable in preservative, but never with lighter crossbands).
Chironius challenger is mostly distinguished from C. fuscus by the following characters (characters of C. fuscus in parentheses): absence of apical pits (present, at least on neck), absence of paravertebral keels (usually present, even if faint in females), loreal as high as long or only slightly longer than high (distinctly longer than high), higher number of ventrals - minimum 152 in C. challenger (maximum 149 in C. fuscus from the Guiana Shield), shorter tail - 30–31% TTL in C. challenger (34–37% TTL in C. fuscus from the Guiana Shield), lower number of subcaudals - maximum 103 in C. challenger (minimum 118 in C. fuscus from the Guiana Shield), infralabials 9 (usually 10), ventrals in adults conspicuously mottled with darker edges (not heavily mottled, no conspicuous darker edge), skin between scales blue in life (white).
|Comment||Habitat: partly arboreal (Harrington et al. 2018).|
|Etymology||The specific epithet is considered to be a noun in apposition and refers to Professor George Edward Challenger, the fictional main character of Sir Arthur Conan Doyle's famous novel "The Lost World" published in 1912. "The Lost World" depicts an epic expedition to an isolated tepui in the middle of the tropical jungle of northern South America in search of dinosaur-like creatures and a forgotten civilisation. The reading of Sir Conan Doyle’s novel when Philippe Kok was a child fuelled his thirst for exploration and adventure and positively influenced his research and interest in the Pantepui region.|