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Recent taxonomic studies of forest habitats in South Africa have revealed the presence of three new species of freshwater crabs, suggesting that decapod diversity within the indigenous forest biome remain poorly documented. Surveys of the freshwater crabs of north eastern KwaZulu-Natal province produced a number of specimens from Ntendeka Wilderness Area (Ngome forest) and Nkandla and Ngoye forests that proved to belong to two new species following morphological and molecular analysis (mtDNA sequencing of three loci, 12S rRNA, 16S rRNA and COI). Two undescribed species, P. ntendekaensis sp. nov. and P. ngoyensis sp. nov. are described. The divergence time estimation of the new phylogeny for eastern and southern African freshwater crabs is discussed to illuminate biogeographic patterning and to understand factors responsible for cladogenesis.

We investigate the phylogeographic structure of a fossorial forest-living snake species, the forest thread snake, Leptotyphlops sylvicolus Broadley & Wallach, 1997 by sampling specimens from the Eastern Cape and KwaZulu-Natal provinces of South Africa. Phylogenetic results, using Bayesian inferences and maximum likelihood, from the combined mitochondrial sequence data (cyt b and ND4), along with population genetic analyses suggest the presence of phylogeographic breaks broadly congruent to those exhibited by other forest-living taxa. Divergence-time estimates indicate that cladogenesis within the study taxon occurred during the late Miocene climatic shifts, suggesting that cladogenesis was driven by habitat fragmentation. We further investigate the species-level divergence within L. sylvicolus by including two partial nuclear loci (PRLR and RAG1). The three species delimitation methods (ABGD, bGMYC, and STACEY), retrieved 10-12 putative species nested within the L. sylvicolus species complex. These results were corroborated by iBPP implementing molecular and morphological data in an integrative Bayesian framework. The morphological analyses exhibit large overlap among putative species but indicate differences between grassland and forest species. Due to the narrow distributions of these putative species, the results of the present study have further implications for the conservation status of the L. sylvicolus species complex and suggest that forest and grassland habitats along the east coast of South Africa may harbor significantly higher levels of diversity than currently recognized.

We examined the systematics of a ubiquitously distributed southern African freshwater crab, Potamonautes sidneyi s.l. species complex. Specimens were subjected to DNA sequence analyses of two mitochondrial loci (16S rRNA + COI). We applied three species delimitations methods (ASAP, bGMYC and bPTP) to test their utility in delineating species boundaries in Potamonautes and three additional Afrotropical genera (Liberonautes, Nesonautes and Seychellum). The combined mtDNA dataset retrieved five clades. Clade 1 comprised of P. barbarai, clade 2 comprised of specimens from the interior of the Great Karoo Basin, sister to P. sidneyi s.s. in clade 3. Clade 4 was confined to Eswatini and the Mpumalanga Province of South Africa, and sister to clade 5 that comprised P. danielsi. The three species delimitation methods either over- or underestimated the number of species. Phylogenetically, specimens from the Great Karoo Basin (clade 2) were equidistant to P. sidneyi s.s. and P. perlatus, while the Eswatini and Mpumalanga specimens (clade 4) were sister to P. danielsi. Clades 2 and 4 are herein described as P. karooensis sp. nov. and P. valles sp. nov., respectively.

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Aim: Comparative phylogeographic studies provide important insights into the biogeographic processes shaping regional patterns of diversity. Yet, comparative studies are lacking for southern African herpetofauna, despite their high diversity. We statistically compare phylogeographic structure and divergence-time estimates among five co-distributed forest-living herpetofaunal taxa to assess rivers, climatic refugia and climatic gradients as congruent drivers of phylogeographic diversity.Location: Maputoland-Pondoland-Albany biodiversity hotspot, Southern Africa. Taxon: herpetofauna (reptiles and amphibians).Methods: Phylogeographic structure and divergence-times within species were estimated from mitochondrial and nuclear DNA sequence data. Phylogeographic concordance factors were used to estimate the degree of phylogeographic congruence among sympatric localities. Full-likelihood Bayesian comparisons were used to estimate synchronous divergence between phylogeographic regions and across a putative river barrier. Palaeoclimatic niche models were compared among taxa to identify congruent climatic refugia. Nonparametric statistics were used to identify climatic differences between regions and among populations within each species. Finally, redundancy analyses were used to assess geographic distance, climate and the putative river barrier as explanatory variables to genetic diversity. Results: There is comprehensive phylogeographic structuring within each species, comprising distinct northerly and southerly clades. Phylogeographic concordance factors generally support co-diversification in a north/south axis. Yet, analyses of the divergence-time estimates through the Mio/Plio/Pleistocene indicate asynchronous phylogeographic histories. Climatic niche models identified idiosyncratic responses to palaeoclimatic change. Climatic variables are significantly different among populations in all species and correlated with latitude. A combined model of distance, climate and rivers explained the greatest proportion of genetical diversity in most taxa, of which climate explained the highest variance. Main Conclusions: Ancient and recent species-specific responses to climatic and geological processes resulted in pseudo congruent phylogeographic histories among the five co-distributed species. The presence of a congruent north/south pattern in multiple taxonomic groups occupying different forested microhabitats, from fossorial to arboreal, supports latitudinal gradients as global drivers of phylogeographic diversity along the east coast of South Africa.

The African genus of fossorial legless lizards (Acontias Cuvier) currently comprises 26 species and subspecies. In a recent study on the two disjunct populations of Acontias breviceps Essex, the presence of cryptic species was discovered. Here, we increase the sampling size and describe these disjunct populations from the Mpumalanga Escarpment of South Africa as new species. The new species differ from congeners based on a combination of factors, including the number of midbody, ventral, and subcaudal scale counts, ventral pigmentation, allopatric distributions, and genetic divergences. The new species are genetically distant from nominal A. breviceps, with which it shares overall pigmentation and scalation. The new description adds to the growing number of Mpumalanga escarpment endemic reptiles, and highlights the area as a biodiversity hotspot. The use of vertebral counts as a distinguishing character between species is briefly discussed.

Phenotypic convergence of traits in similar environments can provide insights into the evolutionary processes shaping trait evolution. Among squamate reptiles, horn-like cephalic appendages have evolved under various selective pressures, including selection for defence, crypsis or sexual selection. Yet, among snakes, particularly vipers, the functional and evolutionary significance of horns are unknown. We used a comparative phylogenetic approach with habitat and diet data on 263 viper taxa to shed light on the selective pressures underlying horn evolution in vipers. We detected significant correlations with habitat but not diet. The relative positions of horns are ecologically divergent in that supranasal horns are positively correlated with terrestrial forest habitats while supraocular horns are negatively correlated with terrestrial forest habitats and are instead associated with arboreal or sparsely vegetated habitats. Multiple independent origins of supranasal or supraocular horns in similar habitats provide evidence of adaptive convergence. Comparisons with other snake lineages suggest that cephalic appendages may have evolved under selection for crypsis in ambush foraging snakes.