Rediscovery ofBoulengerula denhardtiNieden 1912 (Amphibia: Gymnophiona: Caeciliidae) in Meru County, Kenya

A new species of Boulengerula Tornier, 1896 (Amphibia: Gymnophiona: Herpelidae) from Kenya and the “rediscovery” of Boulengerula denhardti

“…There is also at least one obvious and substantial difference in external morphology between the Boulengerula from the Nyambene Hills and the holotype and only previously reported specimen of B. denhardti. Measey et al (2012) give the distances from the tentacle to the tip of the snout and to the corner of the mouth, with the former much larger (2.5 mm) than the latter (1.5 mm) in the holotype of B. denhardti but this difference is reversed in the Nyambene Boulengerula, reflecting the latter's substantially more anterior tentacles. Tentacle position is an often used character for differentiating caecilian taxa.…”

“…denhardti." However, this identification is plainly contradicted by the presence of inner mandibular teeth in the Nyambene Hills Boulenegerula (as noted by Measey et al 2012), the absence of which was used by Wilkinson et al (2004) in their diagnosis of B. denhardti and in their key to the species of Boulengerula. Presence or absence of inner mandibular teeth has been used previously as a diagnostic character for species of Boulengerula (e.g.…”

“…Measey et al (2102) state that this type locality is widely interpreted as being the Tana River Delta, approximately 420 km southeast of the Nyambene Hills. Having mistakenly believed they had rediscovered B. denhardti, Measey et al (2012) proposed that the distributional gap between the Nyambene Hills and the Tana River Delta could be explained by the former falling within the catchment of the Tana River and by the implication that these localities may have been connected by forested riverine corridors along which caecilians could have dispersed. Our finding that the specimens from Nyamabene Hills are not conspecific with B. denhardti but instead represent a new species, obviates any need for the Measey et al (2012) biogeographic scenario.…”

“…Subsequent directed fieldwork by Patrick K. Malonza and Vincent Muchai in May 2008 yielded six additional specimens. These collections formed the basis of the report (Measey et al 2012), 100 years after its description, of the rediscovery of the poorly known species B. denhardti that was previously known only from the holotype specimen from the area of the Tana River in Kenya .…”

“…Here we confirm that they are Boulengerula (lacking secondary annular grooves but possessing stapes) and show that, rather than being B. denhardti, this population of caecilians represents an undescribed eighth species of Boulengerula that we here describe. Consequently, contra Measey et al (2012), B. denhardti has not been rediscoverd in the Nyambene Hills and remains known only from the holotype specimen.…”