| Northern side of Husab Mountain, Namib Park, Swakopmund Dist., S.W.A., Namibia, 22° 40’ S, 15° 08’ E, 750 m elevation. |
Berger-Dell´Mour, H.A.E. & Mayer, W. (1989) - On the parapatric existence of two species of the Pedioplanis undata group (Reptilia: Sauria: Lacertidae) in the central Namib desert (Southwest Africa) with description of the new species Pedioplanis husabensis. - Herpetozoa, Wien, 1 (3/4): 83-95.   × In the course of a survey of the reptile fauna in the central Namib desert near the lower reaches of the rivers Khan and Swakop a yet undescribed lizard of the Pedioplanis undata complex was found to exist parapatrically with Pedioplanis undata inornata. Pro- nounced discontinuity of morphological and biochemical features of the specimens of the contact area proves that the new form is genetically sufficiently separated from Pedioplanis undata to be regarded as a species of its own {Pedioplanis husabensis n. sp.) Makokha, J.S. & Bauer, A.M. & Mayer, W. & Matthee, C.A. (2007) - Nuclear and mtDNA-based phylogeny of southern African sand lizards, Pedioplanis (Sauria: Lacertidae). - Molecular Phylogenetics and Evolution, 44 (2): 622-633. × The diversity of lacertid lizards in Africa is highest in the southern African subcontinent, where over two-thirds of the species are endemic. With eleven currently recognized species, Pedioplanis is the most diverse among the southern African genera. In this study we use 2200 nucleotide positions derived from two mitochondrial markers (ND2 and 16S rRNA) and one nuclear gene (RAG-1) to (i) assess the phylogeny of Pedioplanis and (ii) estimate divergence time among lineages using the relaxed molecular clock method. Individual analyses of each gene separately supported different nodes in the phylogeny and the combined analysis yielded more well supported relationships. We present the first, well-resolved gene tree for the genus Pedioplanis and this is largely congruent with a phylogeny derived from morphology. Contrary to previous suggestions Heliobolus/Nucras are sister to Pedioplanis. The genus Pedioplanis is monophyletic, with P. burchelli/P. laticeps forming a clade that is sister to all the remaining congeners. Two distinct geographic lineages can be identified within the widespread P. namaquensis; one occurs in Namibia, while the other occurs in South Africa. The P. undata species complex is monophyletic, but one of its constituent species, P. inornata, is paraphyletic. Relationships among the subspecies of P. lineoocellata are much more complex than previously documented. An isolated population previously assigned to P. l. pulchella is paraphyletic and sister to the three named subspecies. The phylogeny identifies two biogeographical clades that probably diverged during the mid-Miocene, after the development of the Benguella Current. This probably led to habitat changes associated with climate and, in conjunction with physical barriers (Great Escarpment), contributed towards speciation within the genus Pedioplanis. Kirchhof, S. & Hetem, R.S. & Lease, H.M. & Miles, D.B. & Mitchell, D. & Müller, J. & Rödel, M.-O. & Sinervo, B. & Wassenaar, T. & Murray, I.W. (2017) - Thermoregulatory behavior and high thermal preference buffer impact of climate change in a Namib Desert lizard. - Ecosphere, 8 (12): 1-22. × Knowledge of the thermal ecology of a species can improve model predictions for temperatureinduced population collapse, which in light of climate change is increasingly important for species with limited distributions. Here, we use a multi-faceted approach to quantify and integrate the thermal ecology, properties of the thermal habitat, and past and present distribution of the diurnal, xeric-adapted, and active-foraging Namibian lizard Pedioplanis husabensis (Sauria: Lacertidae) to model its local extinction risk under future climate change scenarios. We asked whether climatic conditions in various regions of its range are already so extreme that local extirpations of P. husabensis have already occurred, or whether this micro-endemic species is adapted to these extreme conditions and uses behavior to mitigate the environmental challenges. To address this, we collected thermoregulation and climate data at a micro-scale level and combined it with micro- and macroclimate data across the species’ range to model extinction risk. We found that P. husabensis inhabits a thermally harsh environment, but also has high thermal preference. In cooler parts of its range, individuals are capable of leaving thermally favorable conditions—based on the species’ thermal preference—unused during the day, probably to maintain low metabolic rates. Furthermore, during the summer, we observed that individuals regulate at body temperatures below the species’ high thermal preference to avoid body temperatures approaching the critical thermal maximum. We find that populations of this species are currently persisting even at the hottest localities within the species’ geographic distribution. We found no evidence of range shifts since the 1960s despite a documented increase in air temperatures. Nevertheless, P. husabensis only has a small safety margin between the upper limit of its thermal preference and the critical thermal maximum and might undergo range reductions in the near future under even the most moderate climate change scenarios. Childers, J.L. & Kirchhof, S. & Bauer, A.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): 249–272. × The lacertid genus Pedioplanis is a moderately speciose group of small-bodied, cryptically-colored lizards found in arid habitats throughout southern Africa. Previous phylogenetic work on Pedioplanis has determined its placement within the broader context of the Lacertidae, but interspecific relations within the genus remain unsettled, particularly within the P. undata species complex, a group largely endemic to Namibia. We greatly expanded taxon sampling for members of the P. undata complex and other Pedioplanis, and generated molecular sequence data from 1,937 bp of mtDNA (ND2 and cyt b) and 2,015 bp of nDNA (KIF24, PRLR, RAG-1) which were combined with sequences from GenBank resulting in a final dataset of 455 individuals. Both maximum likelihood and Bayesian analyses recover similar phylogenetic results and reveal the polyphyly of P. undata and P. inornata as presently construed. We con- firm that P. husabensis is sister to the group comprising the P. undata complex plus the Angolan sister species P. huntleyi + P. haackei and demonstrate that P. benguelensis lies outside of this clade in its entirety. The complex itself comprises six species including P. undata, P. inornata, P. rubens, P. gaerdesi and two previously undescribed entities. Based on divergence date estimates, the P. undata species complex began diversifying in the late Miocene (5.3 ± 1.6 MYA) with the most recent cladogenetic events dating to the Plio- cene (2.6 ± 1.0 MYA), making this assemblage relatively young compared to the genus Pedioplanis as a whole, the origin of which dates back to the mid-Miocene (13.5 ± 1.8 MYA). Using an integrative approach, we here describe Pedioplanis branchi sp. nov. and Pedioplanis mayeri sp. nov. representing northern populations previously assigned to P. inornata and P. undata, respectively. These entities were first flagged as possible new species by Berger-Dell’mour and Mayer over thirty years ago but were never formally described. The new species are supported chiefly by differences in coloration and by unique amino acid substitutions. We provide comprehensive maps depicting historical records based on museum specimens plus new records from this study for all members of the P. undata complex and P. husabensis. We suggest that climatic oscillations of the Upper Miocene and Pliocene-Pleistocene era in concert with the formation of biogeographic barriers have led to population isolation, gene flow restrictions and ultimately cladogenesis in the P. undata complex.
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