Geophis, Wagler, 1830

MYERS, CHARLES W., 2003, Rare Snakes-Five New Species from Eastern Panama: Reviews of Northern Atractus and Southern Geophis (Colubridae: Dipsadinae), American Museum Novitates 3391, pp. 1-48 : 28-30

GENUS GEOPHIS

This genus was admirably revised by Downs (1967), who recognized four species in Panama — brachycephalus , championi , godmani , and hoffmanni . Among subsequently described species were two from neighboring Costa Rica ( G. downsi Savage , 198l; G. talamancae Lips and Savage, 1994 ) and one from Colombia ( G. betaniensis Restrepo and Wright, 1987 ). 12

There has been confusion concerning the distribution of this genus in Panama, where there have been no good published records east of El Valle de Antón in Coclé Province ( G. hoffmanni ). Reports of G. godmani and G. brachycephalus in central or even eastern Panama are based on apparently mislabeled specimens from the GML snake census and extrapolations therefrom. Nonetheless, as evidenced by a specimen reported herein, a widely disjunct population of G. brachycephalus does occur in the uplands east of the Panama Canal, and G. hoffmanni also occurs there, as well in the central Panamanian lowlands and probably in northern Colombia. As also to be discussed, Geophis brachycephalus s.l. seems to include an unrecognized sibling species in western Panama.

One new species seemingly endemic to central Panama is described herein. The following key includes the species now known to occur in Panama.

KEY TO PANAMANIAN GEOPHIS

1. Supraocular present, parietal plate not in contact with eye; tip of snout not noticeably paler than rest of head.............. 2

– Supraocular absent, parietal bordering posterodorsal part of eye; tip of snout whitish, contrasting with adjacent head scales............................ G. godmani

12 Another South American species ( G. alasukai ) was described by Gasc and Rodrigues (‘‘1979’’ [1980]) from French Guiana, but according to Hoogmoed (‘‘1982’’ [1983]: 230) the name is a junior synonym of Atractus flammigerus .

2. Six supralabials, posterior temporal plate present; body either uniformly dark or conspicuously patterned above.......... 3 – Five supralabials (a large postlabial does not border free edge of lip), temporals absent (i.e., no scales positioned between ultimate supralabial and parietal); uniformly dark above except for light collar in juveniles...................... G. hoffmanni 3. At least posterior dorsal scales keeled; rostral plate not posteriorly extended between internasals; color variable............. 4 – Dorsal scales smooth throughout; rostral posteriorly extended between internasals; dorsum uniformly dark, venter weakly to strongly banded......... G. championi 4. Venter uniformly dark (glossy black in life) like dorsum; conspicuous white nape collar; size small and slender (holotype, an adult male, 201 mm total length).....

........................... G. bellus – Venter pale, never uniformly dark; dorsum uniformly dark or with light blotches or lateral stripe; juveniles with or without a light collar; size larger (adults attaining maximum total lengths greater than 400 mm).........

..... G. brachycephalus and G., species inquirenda

RECORDS EXCLUDED FROM CENTRAL PANAMA

Geophis brachycephalus (Cope) : This is the most common Panamanian Geophis in collections, but Downs’ (1967: 146) statement that it ranges from ‘‘ Costa Rica southward through Panama to Colombia’’ needs correcting. South America was included in the range because of Downs’ synonymizing of the Colombian Geophis nigroalbus , which is shown herein to be distinct based on proportional and hemipenial characters (see Comparisons under Geophis bellus , new species). 13

13 Some confusion concerning the range of Geophis brachycephalus may stem from my long delay in publishing the present paper. I showed Downs the holotype of Geophis bellus sometime in the mid­1960s, which led him ( Downs, 1967: 146, ftnote) to publish a statement doubting that his inclusion of G. nigroalbus in the synonymy of G. brachycephalus was justified. Possibly encouraged by this, Restrepo and Wright (1987) resurrect­ ed the Colombian G. nigroalbus without comment. In turn, Wilson et al. (1988: 416), followed by Lips and Savage (1994: 413–414), retained G. brachycephalus for Colombia and added G. nigroalbus for ‘‘eastern Panama and Colombia’’. The few Colombian specimens assigned by Downs (1967: 153) to G. brachycephalus are tentatively reassigned to G. nigroalbus (see footnote 16), a species not known from Panama.

The only Panamanian specimens of G. brachycephalus with definite locality seen by Downs (1967: 153) are from far western Panama. Central Panama was included on the basis of a series of specimens (ANSP 24723– 24734) from ‘‘ Panama Sabanas’’. These specimens, consecutively numbered with a partial specimen (ANSP 24723) of G. godmani (see below) having the same locality data, are from the GML snake census (see Introduction).

As summarized by Dunn (1949a: 47), the GML ‘‘sabanas collection’’ was accumulated from various localities in the central Pacific lowlands, ‘‘from Capira to the west to Canita [Cañita] in the mid­basin of the Bayano to the east’’—a straight­line distance of 120 km —although ‘‘the majority of the specimens come from the true ‘ Panama sabanas’ which lie between Panama City and Chepo.’’ Dunn (1949a: 47, table 7) reported on over 3900 snakes from this collection, with no mention of Geophis in this or in any other part of the GML lowland collection, even though Dunn presented the ‘‘sabanas’’ Geophis to the Academy of Natural Sciences in 1942, seven years before publication of his summary analysis.

The ‘‘sabanas’’ locality seems wrong on the face of it. Neither G. brachycephalus nor the rare G. godmani are lowland savanna snakes, and the thought that both might have been found in sympatry in such an unlikely habitat is hard to swallow and harder to digest. Furthermore, several specimens of the little montane snake Trimetopon slevini (ANSP 24717–24719) also were presented by Dunn in 1942 and were cataloged as ‘‘ Panama Sabanas’’; neither were these mentioned in Dunn’s 1949a paper. I surmise that Dunn either knew that the locality had to be wrong for these specimens and ignored them, or there was a cataloging error that he either was unaware of or never got around to correcting.

Although the ‘‘sabanas’’ record for Geophis brachycephalus must be discarded as erroneous, this species does occur in upland wet forest in east­central Panama, as demonstrated later in this paper.

Geophis godmani Boulenger : This is a rare snake in Panama, and it evidently is a montane species throughout its range. Downs (1967: 72), followed by Peters and Orejas­ Miranda (1970: 119), gave its distribution as ‘‘Caribbean and Pacific slopes of central Costa Rica southward to the Canal Zone of Panama [at known localities] between 1300– 2100 meters above sea level.’’

The three Panamanian specimens of G. godmani seen by Downs (1967: 75) are all from the GML snake census—two from Finca Lérida in extreme western Panama, the third (ANSP 24722) purportedly from the ‘‘ Panama Sabanas’’ in central Panama. This last specimen is cataloged consecutively with the series of G. brachycephalus and in proximity with the series of Trimetopon slevini discussed above, and the godmani record must be discarded for the same reasons. The most likely correct locality for the ‘‘sabanas’’ Geophis brachycephalus , G. godmani , and Trimetopon slevini is Finca Lérida in Chiriquí Province, which provided some census material and where all three species occur. 14