Pedioplanis branchi, Childers & Kirchhof & Bauer, 2021

Childers, Jackie L., Kirchhof, Sebastian & Bauer, Aaron M., 2021, Lizards of a different stripe: phylogenetics of the Pedioplanis undata species complex (Squamata, Lacertidae), with the description of two new species, Zoosystematics and Evolution 97 (1), pp. 249-272 : 249

Pedioplanis branchi sp. nov. Figs 7 , 8 , 9

Holotype

(Fig. 7 ). Adult ♂; CAS 214788 (field number AMB 6551); Namibia, S of Karibib at Junction of Road D1914 and Road D1952, Karibib District, Erongo Region (-22.27038, 15.57471, 1080 m a.s.l.); collected 8 June 2000 by Aaron M. Bauer. Holotype and part of type series to be transferred to the National Museum of Namibia.

Paratypes.

n = 7 (adults); (two ♀: ZMB 89310, ZMB 89311; five ♂: CAS 214790, CAS 214792, CAS 214794, ZMB 89305, ZMB 89316) collected from various localities located in the Erongo Region of northwestern Namibia • CAS 214790; S of Karibib at the junction of Rd. D19414 and Rd. D1952 (-22.27281, 15.57815, 1075 m a.s.l.); collected 8 June 2000 by Aaron M. Bauer • CAS 214792; same collection data as for proceeding • CAS 214794; same collection data as for proceeding • ZMB 89305; 22 km SW of Uis along C35 (-21.42419, 14.76271, 831 m a.s.l.); 10 August 2014 • ZMB 89316; 22 km SW of Uis along C35 (-21.34513, 14.75676, 884 m a.s.l.); 23 January 2013 • ZMB 89310; Farm Friedhelm Sack (-22.52699, 15.54487, 709 m a.s.l.); 14 October 2014; • ZMB 89311; same collection data as for proceeding; all ZMB specimens collected by Sebastian Kirchhof. Elevation data for the holotype and paratypes was obtained using the GPS, or, if not available, from Google Earth (earth.google.com) using georeferenced GPS coordinates from the collecting localities.

Diagnosis.

Distinguished from P. lineoocellata , P. laticeps and P. burchelli by having 10 longitudinal ventral scale rows (vs. 12 or more). It is distinct from P. benguelensis , P. gaerdesi , P. breviceps , P. namaquensis and P. husabensis in usually possessing a semi-transparent lower eyelid with a brille formed by 2-4 scales (brille formed by a single scale in P. benguelensis and P. gaerdesi , lower eyelid with eight opaque scales in P. husabensis and opaque and scaly in P. breviceps and P. namaquensis ); in some rare cases P. branchi sp. nov. may possess a single transparent scale in lower eyelid, those individuals can be distinguished from P. benguelensis and P. gaerdesi by color and dorsal patterning (see below). Dorsal patterning is characterized as being uniformly gray from the mid-back towards the head with a reddish hindbody (posterior half of body) and with a series of pale to bright yellow spots or ocelli on lower flanks, distinguishing it from P. rubens (dorsum and tail uniform red-brown to brick red, lacking conspicuous markings with only a hint of a slightly brighter dorso-lateral line on each side), P. mayeri sp. nov., P. haackei , P. huntleyi , P. undata (dorsum contains bold stripes or other longitudinal elements), P. gaerdesi (never with lateral ocelli, and speckled with very small black or light dots) and P. inornata (spots on flanks are typically pale green, not yellow). It can further be distinguished from all other Pedioplanis (except P. inornata ) in typically having a pair of distinct dark markings on the face, one through the eye and extending onto the supralabials directly below and one more posterior, near the corner of the mouth. The new species is significantly smaller than P. inornata ( P. branchi mean adult SVL = 44.4 mm, max. 49.1 mm, versus P. inornata mean adult SVL 47.3 mm, max. 54.0 mm for specimens sampled here; to 56.0 mm elsewhere [ Bauer and Shea 2006]). The maturity of specimens was confirmed by their mostly or completely fused long bone epiphyses. We also provide several diagnostic characters based on the mitochondrial gene ND2. Pedioplanis branchi sp. nov. can be distinguished from all other members of the P. undata species complex except P. laticeps and P. undata in being characterized by having the amino acid histidine instead of tyrosine at base pair 359 due to a codon change at that position. It can also be distinguished from all other Pedioplanis species except P. laticeps in possessing a thymine at base pair 300, rather than an adenine ( P. benguelensis , P. burchelli , P. gaerdesi , P. haackei , P. huntleyi , P. husabensis , P. inornata , P. mayeri sp. nov., P. namaquensis , P. rubens , P. undata ) or a cytosine ( P. breviceps and P. lineoocellata ).

Description of holotype.

Body relatively slender (SVL 47.5 mm); interlimb distance 16.8 mm; femur 9.5 mm; tibia 8.7 mm; humerus 5.4 mm; forearm 5.7 mm; body length 26.9 mm from groin to collar; collar-snout length 19.3 mm; fourth finger length 4.7 mm; fourth toe length 10.4 mm; head narrow and elongated (head width 55% of head length) with slight constriction at base of rostrum and narrow, pointed snout (width at rear of frontonasal 2.2 mm, width at front of eye 4.4 mm); head length 11.8 mm; head width 6.6 mm; lower jaw length 10.2 mm; eye-ear distance 4.4 mm; eye-nostril distance 4.0 mm; 1.1 mm between the nostrils; complete original tail 92.3 mm, with epidermis missing from posterior portions. Rostral semicircular; contacting nasals; nasals in contact medially, unraised relative to rostral and frontonasal; postnasal contacts nasal, frontonasal, anterior loreal, and enters the nostril; nostrils circular in shape; two loreals, anterior loreal half the length of the posterior loreal; two preoculars; prefrontals in median contact; frontal large, with a narrow posterior projection, bordered anteriorly by the prefrontals and posteriorly by the frontoparietals; frontoparietals in broad medial contact; interparietal in contact anteriorly with both frontoparietals, laterally with the parietals, and posteriorly with the occipital; occipital trapezoidal in shape; two supraoculars, both in medial contact with the frontal and frontoparietals, preceded anteriorly by 8R/8L granules (on left side two granules in contact with prefrontal and one in contact with frontal; on right side two granules in contact with prefrontal and three in contact with frontal); single row of granules dividing anterior supraocular from supraciliaries, and double row of granules dividing posterior supraocular from supraciliaries; two small scales between last supraciliary and parietal; six supraciliaries on each side, the anteriormost longest; lower eyelid with transparent brille formed of two larger, black-edged scales, with a row of five smaller scales beneath; five supralabials anterior to subocular and three supralabials posterior to subocular, on both sides; subocular bordering the lip, its lower edge shorter than its upper; 6R/6L infralabials; first infralabial in contact with the second infralabial, the first chin shield, and the mental; four enlarged pairs of chin shields, with the first three in medial contact and the posterior-most largest; no enlarged temporals; tympanum sunk; no scales projecting significantly past margin of ear opening; enlarged narrow scale at anterodorsal margin of ear opening. 30 gular scales in a straight line between symphysis of chin shields and median collar plate; collar free, comprising nine enlarged plates (median kite-shaped, projecting posteriorly) and extending onto side of neck as a crease that terminates midway up the lateral side; dorsal scales small, juxtaposed, granular, without keels, lateral scales larger towards ventrals; 49 rows of granular scales around the midbody; ventral plates in 10 longitudinal and 31 transverse rows (from collar to groin); plates of the outermost rows squarish, ventral rows usually twice as wide as long; single transverse row of ventrals across chest just behind collar longer than broad; nine enlarged precloacal scales, irregular in shape, median ones larger; centralmost enlarged precloacal in contact with six other enlarged precloacals; scales on upper surface of forearm large, smooth, and overlapping, without keels; scales on lower surface of forearm with a series of enlarged plates, at least twice the width of scales on upper forearm; scales on upper surface of tibia rhombic, subimbricate and distinctly keeled, below with a series of enlarged plates; scales on upper surface of femur granular and smooth with enlarged scales along the anterior margin; 12R/12L femoral pores; subdigital lamellae under fourth toe 26R/28L; scales on tail obliquely rectangular in shape, and strongly keeled.

Color in alcohol.

Dorsum of head gray-tan with distinct black speckles of varying size on the head shields; lateral surface of head with three bold, black vertical bars, one at the anterior margin of eye, one originating on the ventral eyelid and one just posterior to the orbit, all extending onto the supralabial scales; body dorsum uniform gray-tan with small, dense, indistinct black speckles. The flanks bear reticulate patterning and possess a single row of eight ocelli with light gray-blue spots of varying size (comprising 8-11 granules) bordered by indistinct black rings of 1-3 granules in width; black rings of adjacent ocelli either separated by 2-4 granules, or in some cases connected; venter cream; limbs pigmented above similar to dorsum, and white below; dorsum of tail with black speckling that is denser than that of the dorsum of body; tail transitions to pinkish-yellow towards the end; ventral surface of the tail is uniformly light cream.

Variation within the type series.

Measurements for the type series are summarized in Table 2 and mensural (n = 20) and meristic (n = 33) character data based on measurements of additional museum vouchers can be found in Suppl. material 2, 3, respectively. Paratypes have similar scalation to holotype except: the prefrontals are separated by frontal and frontonasal in ZMB 89310 and ZMB 89316; the number of granules in group preceding the anterior supraocular varies from nine to 14; in ZMB 89316 there is only one row of granules dividing the supraoculars from the supraciliaries; in CAS 214794 and ZMB 89305 there are seven supraciliaries and five in ZMB 89310 on both sides of the head (usually six); there are usually 6 to 7 infralabials anterior to the subocular; gular scales in a straight line between symphysis of chin shields and median collar plate 26-32; subdigital lamellae under fourth toe 25-29; femoral pores 10-13 (RL only); presacral vertebrae 23-25.

Coloration in life

(Fig. 8 ). Dorsal coloration and pattern varied considerably across examined specimens. Dorsum of head ranges from uniformly gray to distinctly speckled with black, sometimes with bold dark blotches or vertical bars. Body dorsum gray anteriorly and red-orange posteriorly, sometimes bearing light or dark spots that can be arranged in longitudinal rows, or are irregularly scattered, or may form horizontal bars or chevrons across the posterior dorsum near the tail base; belly uniform cream. The flanks may be patterned with light or dark irregular markings, sometimes forming vertical bars or chevrons, and are always lined with a more or less distinct longitudinal row of yellow spots or yellow-centered ocelli bordered by a broken ring of black granules, which range from 0.5-1.0 mm in diameter. The anterior surface of the thighs sometimes tinged with yellow; limbs and feet uniformly gray (front) or reddish-brown (hind), or speckled with light or black dots or blotches that may form bars. Dorsum of tail is orange-red, often with dense, black speckles.

Coloration (in alcohol).

In comparison to the life coloration, the row of spots along the flanks that appear yellow in life appear gray-blue in preserved specimens and may be conspicuous or faint, and the reddish-brown color of the posterior body and tail appears darker and more grayish.

Distribution.

Pedioplanis branchi sp. nov. is endemic to the Erongo Region in Namibia. Its range stretches from just south of the Swakop River in the South, where it occurs in parapatry with P. husabensis , through the pro-Namib, to the Ugab River and the Brandberg in the north and Mount Erongo and Otjimbingwe in the east, probably occurring in parapatry with P. mayeri all along its northeastern border (see Fig. 6 for map of locality records).

Etymology.

The specific epithet is a patronym formed in the genitive singular honoring our friend and colleague, the British-born South African herpetologist, William Roy Branch (1946-2018), in recognition of his many contributions to African herpetology and in remembrance of many happy trips in the field together.

Natural history.

Pedioplanis branchi inhabits Namibian savanna woodlands and the gravel plains and rocky outcrops in the Namib Desert (Deserts & Xeric Shrublands biome; Olson et al. 2001). The species is active on harder substrates, gravel and bare rock (including marble, granite, basalt), mostly with only sparse vegetation cover and only rarely forages on softer sandy substrates (e.g. in small washes on slopes) or in more grassy patches (Fig. 9 ). Median annual precipitation within the distribution range of P. branchi reaches a maximum of only 187 mm (minimum = 16 mm, median = 142 mm), while mean annual temperatures are similar to those in the distribution of P. mayeri (median = 21 °C, range 19.4-22.5 °C). The species occupies lower elevations, from 77 m a.s.l. near the coast to a maximum of ca. 1190 m a.s.l. near the southeasternmost corner of the distribution along the Swakop River Canyon (median = 968 m a.s.l.). The largest recorded individual was a male (SVL = 50 mm). Breeding season appears to be similar to other southern African Pedioplanis spp. in spring, gravid females were found in December. Sympatric diurnal lizards include, Trachylepis sulcata , Rhoptropus boultoni , Agama planiceps , Matobosaurus validus , and Varanus albigularis , among others.

Conservation status.

Although P. branchi has an extent of occurrence below 20,000 km2 it occurs in an area with low human population density, generally low intensity land use, and a high proportion of suitable habitat. Populations occur in protected areas within Namib-Naukluft Park and Tsiseb Conservancy, and possibly Dorob National Park. Applying IUCN criteria we consider P. branchi to be Least Concern.

Figures

Figure 6. Topographic maps showing locality records for all the species of the Pedioplanis undata species complex and P. husabensis: (a.) P. husabensis (b.) P. mayeri sp. nov. (c.) P. rubens (d.) P. branchi sp. nov. (e.) P. gaerdesi (f.) P. undata (g.) P. inornata. Black dots represent museum vouchers from various museum collections, those with a white center were sequenced and included in the phylogenetic analyses. Museum voucher information was collected from the California Academy of Sciences San Francisco / USA, Carnegie Museum of Natural History Pittsburgh / USA, Ditsong National Museum Pretoria / South Africa, Iziko South African Museum Cape Town / South Africa, Museum fuer Naturkunde Berlin / Germany, Museum of Comparative Zoology Harvard University / USA, Museum of Vertebrate Zoology Berkeley / USA, Natural History Museum of Los Angeles County / USA, Bayworld Museum Port Elizabeth / South Africa, National Museum of Namibia Windhoek / Namibia, Zoological Research Museum Alexander Koenig Bonn / Germany, in parts via the Global Biodiversity Information Facility (GBIF; https: // www. gbif. org /).

Figure 7. Pedioplanis branchi sp. nov., adult male holotype (CAS 214788) from south of Karibib in the Erongo Region of Namibia. (a.) Dorsal and (b.) ventral views of the whole body; scale bars indicate 10 mm; (c.) dorsal, (d.) ventral) and (e.) lateral views of the head; scale bar indicates 2.0 mm.

Figure 8. Life photographs of representative individuals of Pedioplanis branchi sp. nov. highlighting color pattern variation within the species. (a.) Lateral and (b.) dorsal whole body images of an adult specimen from the Chuos Mountains (Chuosberg) (SK 376.2014; not included in study), note the dense, dark speckling on the dorsum, and bold dark lateral markings. (c.) Dorsal and (d.) lateral whole body images of an adult specimen (SK 402.2014; not included in study) from the northward extension of the Swakop River Canyon, note the more uniformly gray and red dorsum lacking speckling and fainter yellow spots along the flanks. Lateral (e.) head and (f.) whole body images of an adult specimen from the northward extension of the Swakop River Canyon; note the black, vertical bar beneath the lower eyelid, the bold, dark lateral markings on the body, and the distinct longitudinal row of yellow spots along the flanks.

Figure 9. Habitat of Pedioplanis branchi sp. nov. (a.) Collection site for ZMB 89310 (Farm Friedhelm Sack, Erongo Region, Namibia) from the extended Swakop River Canyon on a marble / calc silicate slope with sparse grass cover and isolated shrubs. (b.) Collection site for ZMB 89612 (not included in study) from a small hill slope in the Tsiseb conservancy in the Pro-Namib, 20 km south of the Brandberg (visible in the background) depicting a sparsely vegetated scree slope with a Commiphora shrub.