Dendrophidion rufiterminorum CADLE & SAVAGE, 2012
Can you confirm these amateur observations of Dendrophidion rufiterminorum?
|Higher Taxa||Colubridae, Colubrinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Dendrophidion rufiterminorum CADLE & SAVAGE 2012|
Dendrophidion nuchale — CAMPBELL 1998
Dendrophidion rufiterminorum — WALLACH et al. 2014: 226
|Distribution||Belize, Guatemala, N Honduras, Nicaragua, Costa Rica|
Type locality: 1 mi W Baldy Sibun, Cayo district, Belize [17°00’ N, 88°46’ W]
|Types||Holotype: LSUMZ 8901, an adult male; (Figs. 15, 28). Collected 19 July 1963 by Stephen M. Russell and Angelo W. Palmisano (Wilson 1966). An attached field tag has field number “A. Palmisano 177” but LSUMZ collection ledgers record only Russell as the collector (Christopher Austin, personal communication).|
|Diagnosis||Diagnosis. Dendrophidion rufiterminorum is characterized by (1) Dorsocaudal reduction from 8 to 6 occurring posterior to subcaudal 45 (range, 46–79); (2) anal plate nearly always single (divided in 1 of 25 specimens); (3) subcaudal counts > 135 in males and females; (4) head and tail of adults reddish brown to bright red; tail strongly differentiated in color from posterior body and lacking crossbands or ocelli (indistinct crossbands on the anterior part of the tail sometimes present in small individuals); (5) blackish nuchal collar absent in adults and juveniles (Figs. 16, 17, 22A); (6) dorsal coloration in adults anteriorly olive, greenish brown, or brownish, grading to dark brown or blackish posteriorly; dark crossbands or transverse rows of ocelli evident except on the anterior body of adults; (7) central part of ventral scutes usually immaculate (lateral dark pigment is present but no transverse ventral lines) (Fig. 15); (8) total number of enlarged spines on the hemipenis relatively great (> 80); spines in the distal row uniform in size and numbering > 20.|
No species of Dendrophidion except D. rufiterminorum has a distinctly reddish head and tail in life so the adult coloration is diagnostic and distinguishes this species from all others. In preserved adults the head (especially the antorbital region) and tail are usually distinctly paler than adjacent parts of the body (Figs. 15, 16, 18, 21). Dendrophidion rufiterminorum differs from species of the D. percarinatum group in having a more distal dorsocaudal reduction (typically proximal to subcaudal 25 in the percarinatum group compared to > 45 in D. rufiterminorum). Single anal plates occur in the D. percarinatum group only in some individuals of D. paucicarinatum. Dendrophidion boshelli has 15 dorsal scale rows at midbody (17 in D. rufiterminorum).
In addition to coloration, Dendrophidion rufiterminorum differs from species of the D. dendrophis group as follows. The three species of the D. vinitor complex (D. vinitor, D. apharocybe, D. crybelum; Cadle 2012a) have distinct pale bands on the neck and fewer subcaudals (< 130) than D. rufiterminorum (> 135). Dendrophidion dendrophis has a longer tail (> 70% of SVL in adults) and more subcaudals ( 150) than D. rufiterminorum (< 65% and usually < 150, respectively). Dendrophidion atlantica does not have a distinctly reddish head and tail.
Dendrophidion rufiterminorum has previously been confused with D. nuchale and D. clarkii and these three species are very similar in standard scutellation characters (Table 1). Dendrophidion nuchale and D. rufiterminorum are allopatric but the distributions of D. rufiterminorum and D. clarkii overlap on the Caribbean versant of Costa Rica and in uplands of extreme northwestern Costa Rica. Adults of D. nuchale and D. clarkii have a distinct black or dark brown nuchal collar and dark transverse lines and other dark markings on the venter; adult D. rufiterminorum lack nuchal collars and transverse ventral lines and other dark markings on the central part of the ventral scales. The tail of some specimens we refer to D. clarkii (see discussion in that species account) is deep red to bright red like that of D. rufiterminorum. However, in addition to having a nuchal collar, D. clarkii is bright green anteriorly and lacks a reddish head in adults (dull green, olive, or greenish brown anterior dorsum and a red head in D. rufiterminorum). Dendrophidion rufiterminorum has a more posterior dorsocaudal reduction than either D. nuchale or D. clarkii, although there is some overlap in the ranges of the three species for this character (Table 1). All dorsal rows are more consistently keeled in D. rufiterminorum than in D. nuchale or D. clarkii. Finally, Dendrophidion rufiterminorum may have more hemipenial spines than other members of the D. nuchale complex but we have been able to verify this only for specimens from Belize; the possibility of geographic variation cannot be excluded. This is further discussed in the section on hemipenial morphology.
In juveniles of Dendrophidion nuchale and D. clarkii a nuchal collar and dark ventral markings are less distinct or even absent; similarly the head and tail of juvenile D. rufiterminorum are often brown to rusty or orangish, rather than distinctly red. Thus, juveniles of these three species can be easily confused. The tail and/or head of juvenile D. rufiterminorum are reddish brown to brown and somewhat paler than the adjacent portions of the body (see, e.g., Fig. 17 [same photo in Savage 2002: pl. 414] and a photograph of the same individual in Solórzano 2004: fig. 56). The head and tail of juvenile D. nuchale are not differentiated in color and the anterior body and head of juvenile D. clarkii are bright green (Fig. 7A). The dorsocaudal reduction of D. rufiterminorum is distal to subcaudal 45 (< 55 in D. nuchale and D. clarkii; Table 1) [from CADLE & SAVAGE 2012].
|Comment||Similar species: has been considered as D. dendrophis, D. clarkii, or D. nuchale previously.|
D. rufiterminorum differs from D. clarkii and D. nuchale in coloration and hemipenial characters but all three species of the nuchale complex are very similar in scutellation characters.
|Etymology||The species name rufiterminorum is a Latin noun in genitive case meaning “of reddish ends”, referring to the most salient and diagnostic color characteristic of this species, its red head and tail. It is a compound word derived from rufus (red or reddish) + terminus (end or limit), a second declension masculine noun in genitive plural form (terminorum) to reflect the fact that both ends are red.|