Panaspis annettesabinae, Colston & Pyron & Bauer, 2020

Colston, Timothy J., Pyron, R. Alexander & Bauer, Aaron M., 2020, A new species of African Snake-Eyed Skink (Scincidae: Panaspis) from Ethiopia, Zootaxa 4779 (2), pp. 190-200 : 192-195

Panaspis annettesabinae sp. nov.

( Figs. 1–2 )

lsid: http://zoobank.org:XXX

Holotype. TJC264 ( ZMNH H2019,2176 ), unsexed adult, 8km SW of Bedele on the Metu-Bedele Road , Buno Bedele zone, Oromia Region, (-8.4032°, 36.3105° elevation 1840m; datum WGS 84; Fig. 3 ) Ethiopia, 9 February 2013 by Timothy J.Colston.

Diagnosis. Panaspis annettesabinae can be distinguished from other members of the genus by the following combination of characters: eye in the “ablepharine” condition; scales in 24 rows at the midbody; adult coloration of light-colored upper labials lacking round black spots; coppery dorsum flecked with black, separated from dark brown or black lateral coloration by a single row of light-colored scales; and a coppery bronze tail.

Description of the holotype. Unsexed adult in good condition. Body form (size and shape) and scalation typical for Panaspis ( Medina et al. 2016) . Relatively slender, cylindrical body with pentadactyl fore- and hind-limbs. Trunk elongate; limbs do not overlap when adpressed. Mass 1.3g. SVL 42.1 mm, tail broken in preserved specimen; approximately 1.5 times body length in life. Head length 7.5 mm, with modestly acuminate snout (HL 139% HW). Other measurements presented in Table 1. Rostral wider than high, and visible from above. Nasals widely separated behind rostral by frontonasal. Frontonasal acuminate anteriorly, wider than long. Nostrils large, set centrally in the nasals and not bordering the postnasal. Prefrontals in contact with one another, and first supraocular, first supraciliary and frontal separated from frontonasal by supranasals (which are in contact). Two loreals, the posterior margins of the largest loreal border preoculars (3), which is wider than high. Frontal length less than the distance between anterior tip of frontal and tip of snout; frontal in contact with prefrontals anteriorly, six supraoculars (three on each side) and frontoparietals. Frontoparietals fused, in contact with the frontal, two supraoculars (one on each side), parietals and interparietal. Interparietal triangular with visible parietal window in center; parietals 2 times larger than frontoparietals and contacting each other at the anterior point of the interparietal. Parietals in contact at posterior of interparietal. Four large, broad nuchals collectively bordered by a total of nine dorsals. Supraoculars four (per side). Supraciliaries six, third widest, first tallest. Pretemporals two. Tympanum visible, approximately one third the height of the eye. Supralabials seven, V-VII being the suboculars. Ablepharine eye. Infralabials five. Postmental bordering five scales (mental, two primary chin-shields, and one infralabial on each side). Ventral scales smooth. MSR 24, SAD 62, SAV 68. Limbs with five digits; scales on soles of hands and feet smooth. Relative length of digits of manus IV=III>II>V>I relative length of digits of pes IV>III>II>I>V. Finger-IV scales 12. Tail long, robust and tapering smoothly in life, tail broken on preserved specimen.

Coloration in life. Dorsum coppery brown, distinct from darker brown lateral coloration separated by a lighter (whitish tan) stripe encompassing a single scale row. Coppery dorsal coloration flecked with black, loosely arranged in 3–5 irregular lines which become less distinct posteriorly, each black fleck representing one-quarter to one-half of a dorsal scale. Darker brown lateral coloration irregularly interspersed with whitish and blackish speckles. Limbs uniformly darker chocolate brown, with occasional whitish flecking. Coppery dorsal coloration extends onto head scales, uniformly merging into tan-colored rostral. Blackish streak from nostril to orbit, dividing coppery dorsal coloration from whitish labials. Anterior tail coloration (proximo-anterior) similar to limbs, a continuation of the coppery dorsal coloration darkened to uniform chocolate brown. Posterior portion of tail (approximately the final one-third) lighter, more metallic copper coloration, possibly old regrowth or breeding plumage. Ventral coloration not recorded in life

Coloration in preservative. In preservative, entire specimen with uniformly milky coloration suggestive of imminent ecdysis. Limbs and light brown, noticeably lighter than the body. Venter uniformly whitish beige, as are underside of limbs. Remnants of narrow dorsolateral stripe still visible, as are black flecks on the dorsum. Unbroken portion of tail and examination of limbs reveals clusters of melanophores across each light-colored scale. Darker blotches evident on tips of dorsal cephalic scales which are otherwise grey or light brown. Coloration of lateral surfaces similar to life, though clouded and faded due to preservation.

Comparison with other Ethiopian Panaspis . As noted above, only two species are currently considered to occur in Ethiopia: P. tancredi (known from a single specimen from the northern part of the country—most likely near the region of Debarik, approximately 550km from the type locality of P. annettesabinae in markedly different habitat), and scattered records in the south-central and western regions previously assigned to P. “ wahlbergi ” s.l. Medina et al. (2016) restricted the nominotypical form to southeastern Africa, and revealed that there are no phylogenetically close congeners of TJC264 ( P. annettesabinae ), which was the sole member of a long branch in all analyses. In their analyses P. annettesabinae is the sister lineage either to most southern African species or several southeastern lineages, dating at least to the Oligocene ~33Ma. As also noted by Ceríaco et al. (2018), the extreme morphological conservatism and crypsis of these species makes comparison and identification difficult in the absence of molecular data. Thus, appropriate and robustly adequate comparisons are difficult and unclear for P. tancredi .

From the only known specimen of P. tancredii (an unsexed animal of unknown reproductive status), P. annettesabinae is distinguished by a larger body size (SVL 42.1mm versus 28), 24 dorsal scale rows at midbody (versus 22), blackish flecking on the dorsum (versus lack thereof), whitish flecking on the lateral surfaces (versus lack thereof), and lack of round black spot on upper and lower labials (versus presence). Largen and Spawls (2010) included photographs of two specimens of P. “ wahlbergi ” s.l. from Ethiopia. Neither of these specimens were indicated to have been collected or deposited in a museum for examination. The first (Fig. 267, p. 408) is an adult or subadult from Debre Zeit (Bishoftu) in the central region, and closely resembles the holotype of P. annettesabinae . The second (Fig. 268, p. 408) is a juvenile from Bedele, near the type locality of P. anettesabinae . This specimen also resembles a juvenile version of the holotype, with darker limbs and lateral coloration and less evident dark flecking dorsally and light flecking laterally. A key difference is that the juvenile specimen has a bright blue tail in contrast to the orange tail of the holotype and the Debre Zeit specimen (the latter appears to be regenerated, while the holotype had its original tail in life), though ontogenetic color-change in skink tails (particularly in breeding males) is relatively common. Finally, a series of specimens from Negele Borena in southern Ethiopia represents another new, highly distinct species based on molecular and morphological data (TJC in prep.), suggesting that many of the remaining central and eastern records may belong to this or other new species.

TABLE 1 . Measurements (in g or mm) and scale counts of the holotype; abbreviations given in the Materials and Methods and definitions following Ceríaco et al. (2018) .

Distribution. This species is currently known only from the type locality ( Fig. 3 ). Additional fieldwork will be needed to determine the geographic extent of the species’ range. As noted, a juvenile specimen from near the type locality ( Largen and Spawls 2010) likely represents an additional record of this species, while an adult or subadult specimen from Debre Zeit may extend the range into central Ethiopia.

Habitat and Natural History notes. The habitat at the type locality is a clearing within moist evergreen montane forest (elevation 1840m) in the Oromia Region of southwestern Ethiopia ( Fig. 4 ). This clearing is likely of man-made origin, although natural “glades” within this forest type are known. The clearing sits alongside a stream that has been diverted for use by the Bedele Brewing company, which granted TJC access to camp on and survey the area. While P. annettesabinae is likely more common in forest openings, the type specimen was found underneath a tarp in basecamp during camp maintenance, and it should be noted that while pitfall traps were utilized in the immediate area for 21 consecutive days no other specimens of Panaspis were collected.

Etymology. The specific epithet “ annettesabinae ” honors Annette Sabin of the Sabin family, long-time philanthropic supporters of biodiversity conservation. We propose the English vernacular name “Sabin’s Snake-Eyed Skink.”

Figures

FIGURE 1. Holotype of Panaspis annettesabinae (TJC264, ZMNH H2019,2176) in life. Photo by TJC.

FIGURE 2. Photographs (dorsal and ventral view) of the holotype of Panaspis annettesabinae (TJC264, ZMNH H2019,2176) in preservative. Photos by TJC.

FIGURE 3. Geographic context of Ethiopian Panaspis. The red star is the type locality of P. anettesabinae, the red circles are literature reports of potential conspecific localities based on photographs in life (Largen and Spawls 2010), the green dot is the type locality of P. tancredi, the blue dot is the recently discovered and undescribed P. sp. nov. reported here, and the grey dots are museum specimens or literature reports of indeterminate specific assignment (see Largen and Spawls 2006, 2010).

FIGURE 4. Habitat of Panaspis annettesabinae at the type locality. The holotype was collected under a tarp in basecamp (above) while Trachylepis maculilabis and T. striata were the only skink species captured in nearby pitfall traps (below) Photos by TJC.