Bothrocophias, Gutberlet Jr. & Campbell, 2001

GUTBERLET, JR, RONALD L. & CAMPBELL, JONATHAN A., 2001, Generic Recognition for a Neglected Lineage of South American Pitvipers (Squamata: Viperidae: Crotalinae), with the Description of a New Species from the Colombian Chocó, American Museum Novitates 3316, pp. 1-16 : 4-6

Bothrocophias , new genus

TYPE SPECIES: Bothrops hyoprorus Amaral ( 1935) , by present designation.

ETYMOLOGY: The generic name is derived from the Greek words bothros, meaning pit, and kophias, meaning snake or adder; the gender of this name is masculine.

CONTENT: The genus Bothrocophias contains four species: campbelli known only from the western slopes of the Ecuadorian Andes; hyoprora distributed throughout the western lowlands of the Amazonian rainforest; microphthalmus , found along the eastern versant of the Andes in Colombia, Ecuador, Peru, and possibly Bolivia; and a new species described below that is restricted to lowland rainforest in western Colombia ( fig. 2).

DEFINITION AND DIAGNOSIS: A lineage of crotaline snakes occurring in northern South America. Members of the four species included in this lineage are of moderate length, relatively stout­bodied, and terrestrial, lacking a prehensile tail. Females attain greater size than do males. The snout is weakly ( B. campbelli and the new species described subsequently in this paper) to strongly ( B. hyoprora and B. microphthalmus ) elevated with a rostral scale that is approximately as high as broad or distinctly higher than broad. Dorsal coloration within the genus consists mainly of darker shades of brown and reddish­brown. A pattern of dorsal banding may be clearly evident or subdued, and in some specimens the bands do not meet evenly at the middorsal line and are staggered as large lateral blotches.

Derived characteristics shared by the four species of Bothrocophias include small, smooth intersupraocular scales; distinctive white spots on gular and infralabial scales; and tuberculate keels on scales on the caudal portion of the dorsum. Many, though not all, specimens of B. hyoprora and B. microphthalmus exhibit tiny scales between the rostral and internasals that have not been observed in any other New World pitviper.

There are 124–177 ventrals; 38–64 subcaudals, most of which are entire in B. hyoprora , but mostly divided in the other three species; 21–25 middorsal scale rows; 2–9 smooth intersupraoculars; 7–8 supralabials; 8–11 infralabials; 1–11 prefoveals; 1–3 canthals; and 3–4 interoculabials.

The osteology of the genus remains poorly known, though we have been able to examine one skull each of Bothrocophias hyoprora and B. microphthalmus . In these two species, the dorsal surface of the frontal bones is predominantly flat. The postfrontals are large, contributing more to the dorsal perimeter of the orbit than does the parietal. The posterolateral edges of the dorsal surface of the parietal bear a small lateral shelf of bone. The ectopterygoid has a single pit for the attachment of the ectopterygoid retractor muscle, is approximately equal in length to the base of the pterygoid, and has a broad, flat shaft. The choanal process is positioned medially on the palatine bone and is attenuate distally. The angular and splenial are partially fused, and the Meckellian foramen is divided by a thin extension of bone. Species of Bothrocophias have 4–5 palatine teeth, 12– 15 pterygoid teeth, and 14–16 dentary teeth. The maxillary fang is approximately 1.5 times longer than the height of the maxilla.

We have seen hemipenes of Bothrocophias hyoprora and the species described in this paper. Hemipenes of these species are calyculate distally. Walls of the more proximal calyces are spinulate. Proximal to the calyces, small mesial spines and a moderate number (ca. 18–30 per lobe) of lateral spines are present. Though some lateral spines are noticeably larger than the mesial spines, none can be characterized as basal hooks. The hemipenes of B. hyoprora differ slightly from those of the new species in having longer and more slender lateral spines.

The following combination of characters diagnoses Bothrocophias from all other New World pitviper genera: (1) 7–8 supralabials; (2) small but unkeeled dorsal head scales, not arranged in a nine­plate, colubrid­like pattern; (3) tubercular keels on dorsal scales on posterior half of body; (4) white spots with dark borders on some gulars and infralabials; (5) 124–177 ventrals; (6) 4–5 palatine teeth; (7) 12–15 pterygoid teeth; (8) 14–16 dentary teeth; (9) maxillary fang approximately 1.5 times longer than height of maxilla; (10) mesial spines present on hemipenial lobes; (11) moderate number (ca. 18–30 per lobe) of lateral spines on hemipenes; (12) hemipenial lobes only slightly longer than organ’s base; (13) choanal process of palatine attenuate distally; (14) ectopterygoid and base of pterygoid approximately equal in length; (15) dorsal surface of frontal bones predominantly flat; (16) postfrontal bones large, contributing more to dorsal perimeter of orbit than does parietal; (17) tail not prehensile and lacks a rattle.

Because the species of Bothrocophias have been previously included in the genus Bothrops , it is significant that skull morphology in the two genera is markedly different. In Bothrops (sensu stricto), including such species as B. asper and B. atrox , the skull is relatively narrow and elongate (Werman, 1992, 1999; Gutberlet, 1998a; Gutberlet and Harvey, in press), whereas the skull in Bothrocophias species is broad and heavily ossified. Specific characteristics that typify this divergence in skull morphology are (condition of Bothrops in parentheses): distance across frontals equal to (less than) width of skull at anterior end of supratemporals, shaft of ectopterygoid wide and flat (slender and round in cross section), and shaft of ectopterygoid equal to (greater than) length of base of pterygoid.

The holotype of Bothrocophias campbelli (INHMT 1956) is from Provincia de Chimborazo, Ecuador. As Campbell and Lamar ( 1992) noted, all specimens from Colombia previously assigned to B. campbelli possess a lower number of ventrals and coloration different from those from further south. These differences, in addition to others listed below, clearly indicate that the Colombian snakes represent a distinct species, and this may be known as