Lygodactylus dysmicus, (Perret, 1963) (Perret, 1963)

Lobón-Rovira, Javier, Bauer, Aaron M., Pinto, Pedro Vaz, Trape, Jean-Francois, Conradie, Werner, Kusamba, Chifundera, Júlio, Timóteo, Cael, Garin, Stanley, Edward L., Hughes, Daniel F., Behangana, Mathias, Masudi, Franck M., Pauwels, Olivier S. G. & Greenbaum, Eli, 2024, Integrative revision of the Lygodactylus gutturalis (Bocage, 1873) complex unveils extensive cryptic diversity and traces its evolutionary history, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 201 (2), pp. 447-492 : 468-470

LYGODACTYLUS DYSMICUS Perret, 1963 ( Fig. 12 ; Table 3 )

Lygodactylus angularis dysmicus : Perret (1963).

Lygodactylus gutturalis dysmicus : Pasteur (1964); Kluge (1991, 1993, 2001); Schätti and Perret (1997); LeBreton (1999); Schätti et al. (2002); Röll (2005); de Lisle et al. (2013, 2016).

Lygodactylus (Lygodactylus) gutturalis dysmicus : Rösler (2000).

Lygodactylus dysmicus : Chirio and LeBreton (2007).

Lygodactylus picturatus dysmicus : Thys van den den Audenaerde (1967).

Perret (1963) described L. a. dysmicus from Foulassi, South Region, Cameroon, as the western race of L. angularis that differs from the nominotypical form by its gular ornamentation. However, Perret never compared this species to L. gutturalis in neighbouring areas. In 1991, Kluge considered L. a. dysmicus as a subspecies of L. gutturalis , although he did not provide any justification. This taxonomic change was followed by other authors until Chirio and LeBreton (2007) considered L. dysmicus as a full species in their ‘ Atlas des reptiles du Cameroun ’ again without justification. Until then, the only known record of this species was the holotype; however, Chirio and LeBreton (2007) added a new photographic record from Nglochifen, West Region, Cameroon, in their book. Herein, based on the osteological evidence mentioned above, and the presence of terminal scansors on the tail tip, which are absent in the L. angularis group, we regard L. dysmicus to be part of the L. gutturalis subgroup. Despite the lack of molecular data, distinctive morphology supports the validation of L. dysmicus as a full species, as suggested by Chirio and LeBreton (2007) and Kluge (1991). Based on the detailed description provided by Perret (1963), we provide only a diagnosis and comparison with L. gutturalis s.s. and the L. angularis group.

Holotype: MHNG 1005.72 , adult male, collected from forest at Foulassi , South Region, Cameroon (~ 665 m a.s.l.), at the north-west limit of the Congo Basin. Specimen fixed in formalin, now preserved in ethanol.

Diagnosis ( Fig. 12 ): As noted by Perret (1963), the species differs from the L. angularis group mainly by the gular ornamentation, which consists of two ∩ -shaped chevrons, one within the other, and a central mark vs. two V -shaped marks or broken pattern (in L. heeneni and L. paurospilus ) chevrons that converge posteriorly. It also differs from the angularis group by having a reduced, almost vestigial postorbitofrontal vs. a well-developed postorbitofrontal bone in the angularis group. Lygodactylus dysmicus can be differentiated from L. gutturalis by having more precloacal pores (9 vs. 5–8); nostril in narrow contact with rostral scales vs. never in contact in L. gutturalis . We have also recorded some minor differences as follows: fewer lamellae under fourth toe (4 vs. 5–6); a greater number of ventral scales across the body (21 vs. 15–20); and a greater number of scales between the eyes (25 vs. 17–24). It is noteworthy that L. dysmicus is small [SVL 27.6 mm vs. 33.3 ± 1.8 mm (mean) in L. gutturalis ], with a paedomorphic skull that has an unfused frontal bone, braincase, and compound bone + surangular ( Fig. 5 ). However, the well-developed state of the precloacal pores suggest sexual maturity of this specimen ( Rhen et al. 2005; Fig. 12B ). Finally, L. dysmicus can be differentiated from L. gutturalis based on its distribution in lowland Congolian rainforest vs. the sub-Saharan savannah ( Fig. 6 ).

Habitat and distribution ( Fig. 6 ): Lygodactylus dysmicus is only known from the type locality in Foulassi, South Region, Cameroon, and an additional photographic record (unconfirmed) from Nglochifen, West Region, Cameroon. Lygodactylus dysmicus is considered a rainforest species distributed near the northern limit of the Congolian Rainforest.

Natural history: Diurnal gecko that lives on trees in dense semideciduous forests (Chirio and LeBreton 2007).

Figures

Figure 5. Gular and skull osteology comparisons between holotype material or representative material of all members of the L. gutturalis subgroup and the L. angularis group mentioned in this work.From top to bottom, ventral view gular section; dorsal, lateral, and ventral view of the skull; lateral, dorsal, medial, and ventral view of jaw; and number of tooth loci. PM = premaxilla, MX(R) = right maxilla, MX(L) = left maxilla, DN(R) = right dentary of the jaw.

Figure 6. Geographical distribution of the L.gutturalis complex in Africa, on a hybrid map of the major vegetation divisions (Sayre et al. 2013) and 1 arc-second elevation map across tropical Africa (NASA 2000). Different colours depict records of different species within the L. gutturalis subgroup; see inset for explanations of symbols.White circles denote records of L. cf. gutturalis that cannot be assigned to any of the nominate taxa. Black stars represent the type localities of each nominate taxon within the L. picturatus subgroup (1– L. picturatus, 1S– L. picturatus sudanensis, 1U– L. picturatus ukerewensis, 2– L. inexpectatus, 3– L. keniensis, 4– L. kimhowelli, 5– L. manni, 6– L. mombasicus, 7– L. scorteccii, 8– L. tsavoensis, 9– L. wojnowskii, 10– L. williamsi).

Figure 12. Holotype of L. dysmicus (MHNG 1005.72) from Foulassi, South Region, Cameroon. A, Ventral and dorsal view of body. B, Details of cloacal region. C, Details of left pes. D, Detailed view of head in both lateral views and ventral and dorsal views (from top to bottom). Photos by J.L.R.