Lizards of a different stripe: phylogenetics of the Pedioplanis undata species complex (Squamata, Lacertidae), with the description of two new species

Abstract

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 cytb) 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 confirm 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 Pliocene (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 branchisp. nov. and Pedioplanis mayerisp. 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.

The Angolan bushveld lizards, genus Heliobolus Fitzinger, 1843 (Squamata: Lacertidae): Integrative taxonomy and the description of two new species

“…It is interesting to note that one of the few consistent physical features differentiating the three Angolan Heliobolus species is their coloration patterns, not only of the adults but also of the juveniles. Although coloration in lacertids has traditionally been disregarded as a good diagnostic character for closely related taxa, especially due to the high prevalence of color polymorphism in the family Lacertidae (see Brock et al 2022) and for the difficulty of objectively differentiating between subtle coloration differences, most recent descriptions of southern African lacertids (all backed by molecular phylogenies) have relied on coloration differences to diagnose the newly described species (Conradie et al 2012;Branch et al 2019b;Childers et al 2021;Parrinha et al 2021). This situation agrees with the results of Brock et al (2022) that color polymorphism can be a driver of speciation.…”

Plant speciation in the Namib Desert: potential origin of a widespread derivative species from a narrow endemic

“…García-Aloy et al 2017) and animals (e.g. insects, reptiles:Lamb and Bond 2013;Collins et al 2019;Childers et al 2021). …”