Rediscovery of Furcifer voeltzkowi

Furcifer voeltzkowi was described as Chamaeleon voeltzkowi by Boöttger in 1893, named after Alfred Voeltzkow (1860 – 1947), German zoologist and botanist, who collected the type specimen at the type locality: Antema, Bembatuka Bay, Western Madagascar. 

Since then, noone has seen it alive.

Hillenius (1959) synonymized C. labordi and C. voeltzkowi with Chamaeleo rhinoceratus and insisted on this conclusion in a subsequent paper (Hillenius 1963), but F. voeltzkowi was revalidated by SENTÍS et al. 2018. Hechenbleikner (1942) described Chamaeleo barbouri from Madagascar which is currently considered as synonym of Furcifer labordi (Hillenius 1959; Glaw 2015). 

Few years ago, an expedition has been organized to the type licality, which is not easuly accessible, by Dr. Frank Glaw from Munich. F. voeltzkowi was rediscovered in nature. It may be short-lived, similar to its sister species F. labordi, and thus only present during the rainy season. 

F. voeltzkowi is a medium sized chameleon (SVL 101.3–116.1 mm; TaL 128.6–133.5 mm; TL 234.8–244.7 mm) with the males characterized by an bone=based, abruptly narrowing and distally rounded rostral appendage, ossified portion of rostral appendage with a crenate edge, a high and bulged casque, a conspicuous gular crest not continuous with the ventral crest and cone-shaped dorsal crest cones that continue to the tail crest, a horizontal band on the body side composed of mainly one row of larger rounded scales, a heterogeneous scalation only above the lateral band and obvious axillary pits, postorbitofrontal serrated, prefrontal meeting the premaxillary process of the maxilla with a blunt end with two sharp small protuberances pointing anteriorly, rounded nasal aperture, diminutive supraorbital fontanelle, parietal extending towards the postorbitofrontal, and surangular separated from the prearticular.
Furcifer voeltzkowi is distinct from F. rhinoceratus by a conspicuously higher casque, smaller ratio of the rostral appendage to SVL, and the presence of an obvious gular crest. The more similar F. labordi differs from F. voeltzkowi by a higher number of peripheral scales on rostral appendage (13–17 vs. 10–12), the reticulate light lines that are consistently present on the body side, a thicker, more interrupted lateral band, and more homogeneous pholidosis in absence of larger rounded scales. In skull structure, the prefrontals of F. voeltzkowi and F. labordi differ in shape. The other species in the Furcifer rhinoceratus group (Glaw & Vences 2007), F. antimena, can be distinguished from F. voeltzkowi by the absence of gular and ventral crests, and by much larger dorsal crest cones in males (SENTÍS et al. 2018).