Bradypodion ngomeense, Tilbury, Colin R. & Tolley, Krystal A., 2009

Tilbury, Colin R. & Tolley, Krystal A., 2009, A new species of dwarf chameleon (Sauria; Chamaeleonidae, Bradypodion Fitzinger) from KwaZulu Natal South Africa with notes on recent climatic shifts and their influence on speciation in the genus, Zootaxa 2226, pp. 43-57 : 47-50

Bradypodion ngomeense sp. nov.

Holotype: PEM-R 16621, an adult male collected by Devi Stuart-Fox and Adnan Moussalli in the Ngome Forest, KZN 27° 49’S, 31° 25’ E, on 6th January 2004.

Paratypes: PEM-R 16617 adult female, PEM-R16612 adult male, PEM-R16613 adult male, PEM- R16615 adult female, PEM-R16618 adult male, PEM-R16620 adult female, PEM-R 16622 adult female, all collected by Devi Stuart-Fox and Adnan Moussalli with same locality and date as holotype; PEM-R 16842 sub-adult male, PEM-R 16843 adult female collected by Colin Tilbury 05/01/2002 same locality as the holotype; PEM-R5689 adult male & PEM-R5690 adult female, collected by Colin Tilbury 08/01/1999, Ngome Forest; PEM-R17518, PEM-R17519, PEM-R17520, PEM-R17521 all collected by Krystal Tolley 14/ 11/2005, locality, Ngome Forest.

Diagnosis: A moderately large-bodied, long-tailed species of the genus Bradypodion demonstrating the characteristics of the genus (Tilbury et al. 2006). This species differs from its various congeners in the following respects: the adults have a relatively tall casque angled at (usually) over 30 degrees or more to the supra-orbital line in keeping with 6 other South African species - viz: B. damaranum (Boulenger 1887) , B. dracomontanum Raw 1976 , some B. ventrale (Gray 1845) , B. thamnobates Raw 1976 , B. transvaalense (Fitzsimons 1930) and B. nemorale Raw, 1978 (Qudeni ecomorph). It differs from B. ventrale which has a tail that is less than 50% of its snout /vent length; from B. thamnobates which has prominent enlarged plate-like flank tubercles; from B. damaranum which has areas of “naked” interstitium around the axilla and along the anterior para-vertebral zone; from B. nemorale which has a relatively much reduced gular crest, and a dorsal crest of cones larger than the diameter of the eye-opening; and from B. transvaalense (sensu stricta) where most adult specimens usually have dorsal cones larger than the eye opening and in which the superior temporal zone is pale coloured and the black mid-temporal stripe continues uninterrupted over the upper and mid flank ( Figure 3 ).

Description of Holotype: Adult male, Snout/vent length 65mm, Tail 81mm. Casque sharply elevated posteriorly. Pre-orbital, supra-orbital, and temporal crests rugose and composed of thick conical and subconical tubercles. A low median parietal crest extends forwards from the apex of the casque to terminate just before the mid-orbital region. The temporal crests originate from the mid post-orbital rim, are prominent and composed of a row of 6 more or less equally enlarged tubercles on the right side and 5 on the left. Posteriorly, the temporal crest then rises almost vertically as the squamosal crest to run parallel and adjacent to the lateral parietal crest to the apex of the casque. A prominent gular crest is present, composed of 14 granulated composite lobes, numbers 2 – 6 overlapping and numbers 2 – 4 are broader than long. The free distal edges of the lobes have a denticulated fringe. Five to six thin white gular interstitial grooves are present on each side of the throat, enclosing chains of enlarged rounded tubercles. A prominent dorsal crest is present, composed of 26 conical tubercles roughly triangular in outline, extending from the nuchal area to the sacrum and then extending along the proximal third of the tail. The tubercles of the dorsal crest are highest over the anterior to mid vertebral line and lowest over the sacral region, none of the cones are taller than the diameter of the eye opening. Background scalation of heterogeneous, rounded to polygonal tubercles with no obvious interstitial venation between the tubercles. A short row of slightly enlarged flattened tubercles skirts the upper mid-flank. Enlarged tubercles are scattered along the para-vertebral zone. Belly tubercles arranged in pallisades of more or less homogeneous rounded tubercles.

Variation in the Paratypes: The largest specimen, a female (PEM-R 16617) has a total length of 166mm (snout/vent 77mm + tail 89mm). Considerable variation in the gular crest is present among the types. The gular crest varies from 11 to 19 individual lobes or tubercles. The length and width of the lobes is variable, in some specimens all the lobes are longer than wide, in others the length / width may be similar and in some the overlapping lobes may be broader than long. Although overlap of between 2 to 7 lobes is common, in several specimens there is no overlap of any of the lobes. In 9/ 12 specimens, the first gular projection is a simple conical tubercle, and in all specimens, the last gular projection is a simple cone. Up to the last 3 gular ornaments may be simple cones. In most specimens the flanks appear to have no interstitial web, but in 2/ 14 specimens, an indication of interstitial webbing was present. The dorsal crest in the type series consisted of between 19 – 26 tubercles extending between the nuchal fold to the mid-sacrum. It may additionally extend for a variable distance along the tail from being almost imperceptible to easily discernable up to half of the length of the tail. The tail is always longer than the snout/vent length in both sexes.

Sexual dimorphism: Males tend to have a more rugose scalation, better developed body and head crests, and a prominent hemipenal bulge at the base of the tail. Tail length differs between the sexes, being 53–57% of the total length in males compared to 53–55% in females. Colour differences between the sexes are discussed below.

Colour in life: Male—Head above the upper labials mostly black – labials and all cranial crests pale yellow. Gular region and gular crest white. Nuchal fold - white to pale yellow. Skin of eyeball, heavily flecked with red around the periphery and a single dark horizontal stripe transects the eye. Background colour of the body is blue-green as is the dorsal crest. A bright red to orange flash over the mid flank is fully enclosed within a black flank patch which terminates abruptly about 2/3rds of the way along the flank. The colour of the flash is variable from white to various shades of red. Belly, front legs and tail blue-green. Female – Background pale green. The superior and inferior temporal zones have white patches. The superior half of the anterior 2/3rds of the flank is dark green, with scattered lighter tubercles ( Figures 4 & 5 ).

Hemipenes: None of the specimens currently present in any museum collection have fully everted hemipenes so the structure of these organs remains un-described for the present.

Habitat: Northern Afrotemporate “Mist Belt” forest between 500 and 1360 meters a.s.l. characterized by a tall, but multi-layered canopy up to 30 meters with both Afrotemperate species and sub-tropical elements (Mucina & Geldenhuys 2006). The forest occupies the deeply incised southeast facing slopes of the Ntendeka cliffs. The largest trees in the Ngome Forest are specimens of the forest waterwood ( Syzygium gerrardii ) reaching up to 30 meters. Other trees include Podocarpus latifolius, Octea kenyensis, Faurea macnaughtonii , Olinia radiata and Trichocladus grandiflorus . The forest is rich in species of epiphytic orchids and hydrophilous ferns. Most specimens collected in the type series were found along forest paths and the road verges in bushes and trees at perch heights between 1–10 meters from the ground.

Conservation: The entire known range of this species is restricted to the Ngome Forest. It is the largest fragment of Mist Belt forest in KwaZulu-Natal with an estimated area of 3360 Ha (36.6 km 2 - Mucina & Rutherford 2006.). Between 1876 and 1899, the forest was heavily logged and most of the larger Podocarpus and other hard wood species were removed or depleted. The forest has been protected since 1905. Much of the forest (2,636 Ha) is managed by the South African Department of Water Affairs and Forestry (DWAF) and protected within the Ntendeka Wilderness Area. Although some of the adjacent scarp area has been given over to pine plantations, there is no pine within the Wilderness Area.

Etymology: The species is named after the Ngome Forest - the only forest known to harbor this taxon.

Figures

FIGURE 3. Head detail of Bradypodion ngomeense sp. nov. Adult male.

FIGURE 4. Bradypodion ngomeense sp. nov. Adult male, Ngome Forest, KZN.

FIGURE 5. Bradypodion ngomeense sp. nov. Adult female, Ngome Forest, KZN.