Sunday, December 7, 2025

[Herpetology • 2025] Adhaerobufo wokomungensis • A New Species of Adhaerobufo (Anura: Bufonidae) from the Wokomung Massif, Guyana, confirms A Key synapomorphy in its sister Genus Rhaebo

 

Adhaerobufo wokomungensis
Kok & Means, 2025
 
 
Abstract  
A new species of toad in the genus Adhaerobufo is described from the Wokomung Massif in the Pantepui region of Guyana, South America. The new species is morphologically similar to – and has previously been confused with – A. nasicus but is unique among Adhaerobufo in lacking a bright, conspicuous white stripe or white spots on the lower lip in adults in life, in lacking visible preorbital and pretympanic crests and in having tubercles between Fingers I-III in males and a small projecting prepollex in both sexes. An updated distribution map for A. nasicus is provided. The colour of parotoid macrogland secretions in Adhaerobufo is reported as a new diagnostic character to distinguish the genus from Rhaebo, its sister taxon.

KEYWORDS: Pantepui, parotoid macrogland secretions, systematics, taxonomy


Adhaerobufo wokomungensis sp. nov.  
Adhaerobufo nasicus (in part) Dias et al. 2024: 14
 
Etymology: Named after the type locality, the Wokomung Massif in west-central Guyana; adjective in the nominative case.

Definition and diagnosis: A bufonid of the genus Adhaerobufo as diagnosed based on 1) molecular phylogenetic evidence (Dias et al. 2024; Fig. 5), 2) white parotoid macrogland secretions (see Discussion and Fig. 1), and 3) suctorial tadpole (Dias et al. 2024). Adhaerobufo wokomungensis sp. nov. is characterised by the following morphological characters, the combination of which distinguishes it from the only two known congeners (A. ceratophrys and A. nasicus): 1) medium-sized toad with a robust body and a SVL of 41.6-45.3 mm in males (n = 2), 60.9 mm in the only known female, 2) snout pointed in dorsal view, round in lateral view, head slightly wider than long, 3) tympanum indistinct, 4) outer edge of the eyelid with rounded dermal projection, 5) low canthal crest, loreal region concave, 6) underlip lacking a bright, conspicuous white stripe or white spots in live adults, 7) preorbital, pretympanic and parietal crests absent, low supraorbital, low postorbital, low supratympanic crests present, 8) nostrils oval, directed posterolaterally, below the canthus rostralis, 9) single enlarged rictal tubercle absent, 10) choanae medium-sized, ovoid, ... 

Adhaerobufo wokomungensis sp. nov. in life.
A) Holotype (IRSNB4223, male, 45.3 mm snout-vent length), B) paratypes in situ, in amplexus (IRSNB4224, male, and IRSNB4225, female),
C) uncollected male, D) white parotoid macrogland secretions produced by the same specimen as illustrated in C. Photos D.B. Means.

Underlip condition in live Adhaerobufo nasicus (A – bright white; IRSNB15678), Adhaerobufo wokomungensis sp. nov. (B – unmarked; holotype, IRSNB4223) and Adhaerobufo ceratophrys (C – bright white; QCAZ55426). Note also the condition of the dermal projection on the outer edge of the eyelid and of the preorbital and pretympanic crests.
Photos P.J.R. Kok (A), D.B. Means (B), and courtesy Diego Quirola-BIOWEB,  https://bioweb.bio (C). Images not at scale.


Philippe J.R. Kok, D. Bruce Means. 2025. A New Species of Adhaerobufo (Amphibia, Bufonidae) from the Wokomung Massif, Guyana, confirms A Key synapomorphy in its sister Genus RhaeboJournal of Vertebrate Biology. 74 (25085), 25085.1-10. DOI: doi.org/10.25225/jvb.25085 (11 November 2025)