Amnesteophis melanauchen (JAN, 1863)
Can you confirm these amateur observations of Amnesteophis melanauchen?
|Higher Taxa||Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Enicognathus melanauchen JAN 1863: 267|
Enicognathus melanauchen — JAN 1866
Rhadinaea melanauchen — BOULENGER 1894: 175
Liophis melanauchen — AMARAL 1929: 173
Liophis melanauchen — VANZOLINI in PETERS & OREJAS-MIRANDA 1986
Echinanthera melanauchen — DI BERNARDO 1992
Amnesteophis melanauchen — MYERS 2011
Amnesteophis melanauchen — WALLACH et al. 2014: 28
|Distribution||Brazil (Bahia), possibly in error|
Type locality: Bahia, Brazil.
|Types||Holotype: RMNH (Leiden)|
|Diagnosis||Diagnosis (tribus): Tribe Amnesteophiini differs from other tribes in Xenodontinae by combination of three unusual character states: (1) straight-line configuration of posterior maxillary teeth; (2) lack of hemipenial calyces; and (3) an unforked sulcus spermaticus. Hemipenial calyces also are absent in the Xenodontini, and an unforked sulcus spermaticus occurs in one species of Echinantherini (Taeniophallus nicagus). Amnesteophis melanauchen somewhat resembles Taeniophallus occipitalis in color pattern and 15 dorsal scale rows, but A. melanauchen differs externally from all Taeniophallus in having feebly keeled dorsal scales.|
Diagnosis (genus): (Based on one adult male.) Genus of small colubrids less than
500 mm in total length, with tail length roughly a quarter of total length; habitus slender, body about as wide as high, slightly wider than head. Color Pattern: Dark nuchal blotch set off by pale crossbands, followed posteriorly by ill-defined narrow brown crossbands. Scutellation: Normal complement of colubrid head plates, possibly with diagnostic arrangement of temporals (in oblique rows, with both plates in first row in contact with labials); dorsal scales in 15-15-15 rows, feebly keeled, lacking apical pits or anal ridges; ventrals 145, anal plate divided, paired subcau- dals 60. Osteology: Maxillary teeth about 25, increasing in size posteriorly, with slight anterior- posterior differentiation in shape; in a continuous series, no diastema; last two teeth slightly enlarged, set in a straight line with the several teeth immediately preceding. About 15 palatine teeth + 30 pterygoid teeth; about 20 teeth on dentary. No hypapophyses on posterior trunk vertebrae. Hemipenis: Feebly bilobed, acalyculate, small spines replaced distally by large flattened soft papillae; unforked sulcus spermaticus extending centripetally to apex of left lobe (sinistral sulcus); a nude area in crotch between the small papillate lobes. Among Neotropical snakes, Amnesteophis melanauchen superficially seems most similar to Taeniophallus sensu lato. It has been compared by authors (Jan, Amaral) with the snake now known as Taeniophallus occipitalis, which shares the character of 15-15-15 dorsal scale rows and a somewhat similar color pattern. It shares with T. nicagus the character of a single (unforked) sulcus spermaticus. Amnesteophis differs from all Taeniophallus in lacking hemipenial calyces, in having the posterior maxillary teeth in a straight line, and in having feebly keeled (vs. smooth) dorsal scales. See Comparisons for further discussion.
|Comment||Nomenclature: The snake generic name Enicognathus and the emendation Henicognathus are both junior homonyms of bird names (MYERS 2011).|
Abundance: very rare; only known from the type specimen (Myers & McDowell 2014)
Type species: Enicognathus melanauchen JAN 1863 is the type species of the genus Amnesteophis MYERS 2011 and of the new tribe Amnesteophiini MYERS 2011.
|Etymology||Amnesteophis (forgotten snake), from Greek amnēstos “forgotten, no longer remembered”) + connective -e- + ophis (“snake”). Gender masculine. (For purposes of euphony, the derivation imposes elision of the final vowel in amnēstos, and the connective vowel -e- is employed rather than the -o- normally used in latinized compounding of Greek elements.) Jan’s specific name melanauchen (a Schlegel manuscript name) appears compounded from the Greek combining element melan- (neuter of melas, “black or very dark”) + auchēn (“neck”)—a masculine noun in apposition, referring to a dark blotch on the neck.|