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Humewood, South Africa

Medina M.F.,University of Texas at El Paso | Bauer A.M.,Villanova University | Branch W.R.,Bayworld | Branch W.R.,Nelson Mandela Metropolitan University | And 12 more authors.
Molecular Phylogenetics and Evolution | Year: 2016

African snake-eyed skinks are relatively small lizards of the genera Panaspis and Afroablepharus. Species allocation of these genera frequently changed during the 20th century based on morphology, ecology, and biogeography. Members of these genera occur primarily in savanna habitats throughout sub-Saharan Africa and include species whose highly conserved morphology poses challenges for taxonomic studies. We sequenced two mitochondrial (16S and cyt b) and two nuclear genes (PDC and RAG1) from 76 Panaspis and Afroablepharus samples from across eastern, central, and southern Africa. Concatenated gene-tree and divergence-dating analyses were conducted to infer phylogenies and biogeographic patterns. Molecular data sets revealed several cryptic lineages, with most radiations occurring during the mid-Miocene to Pliocene. We infer that rifting processes (including the formation of the East African Rift System) and climatic oscillations contributed to the expansion and contraction of savannas, and caused cladogenesis in snake-eyed skinks. Species in Panaspis and Afroablepharus used in this study, including type species for both genera, formed a monophyletic group. As a result, the latter genus should be synonymized with the former, which has priority. Conservatively, we continue to include the West African species P. breviceps and P. togoensis within an expanded Panaspis, but note that they occur in relatively divergent clades, and their taxonomic status may change with improved taxon sampling. Divergence estimates and cryptic speciation patterns of snake-eyed skinks were consistent with previous studies of other savanna vertebrate lineages from the same areas examined in this study. © 2016 Elsevier Inc. Source

Vidal N.,French Natural History Museum | Marin J.,French Natural History Museum | Morini M.,French Natural History Museum | Donnellan S.,South Australian Museum | And 7 more authors.
Biology Letters | Year: 2010

Worm-like snakes (scolecophidians) are small, burrowing species with reduced vision. Although largely neglected in vertebrate research, knowledge of their biogeographical history is crucial for evaluating hypotheses of snake origins. We constructed a molecular dataset for scolecophidians with detailed sampling within the largest family, Typhlopidae (blindsnakes). Our results demonstrate that scolecophidians have had a long Gondwanan history, and that their initial diversification followed a vicariant event: the separation of East and West Gondwana approximately 150 Ma. We find that the earliest blindsnake lineages, representing two new families described here, were distributed on the palaeolandmass of India + Madagascar named here as Indigascar. Their later evolution out of Indigascar involved vicariance and several oceanic dispersal events, including a westward transatlantic one, unexpected for burrowing animals. The exceptional diversification of scolecophidians in the Cenozoic was probably linked to a parallel radiation of prey (ants and termites) as well as increased isolation of populations facilitated by their fossorial habits. © 2010 The Royal Society. Source

Dalhuijsen K.,University of Witwatersrand | Branch W.R.,Bayworld | Branch W.R.,Nelson Mandela Metropolitan University | Alexander G.J.,University of Witwatersrand
African Zoology | Year: 2014

We present data from gut content analyses of Varanus albigularis (savanna monitor) and V. niloticus (water monitor) in South Africa. Both species are generalist, opportunistic feeders. We did not detect any sex-based differences in the diet of V. albigularis, and there were relatively high levels of dietary overlap between the species, although there were significant differences for certain prey types. These differences match differences in habitat use between the species: the more aquatic V. niloticus consumed aquatic prey, such as amphibians and crabs, more often than did V. albigularis. Varanus albigularis included more terrestrial prey such as diplopods in its diet. Tortoises and millipedes were also prominent in the V. albigularis diet, constituting an important component of dietary intake. Few of our samples from V. albigularis had empty stomachs, suggesting that this species may occupy a lower trophic level than its Australian counterparts. Although there is a large degree of overlap in the diets of the two species, there is a trend for V. albigularis to eat more slow-moving prey. These differences result in the species foraging at different trophic levels. Source

Conradie W.,Bayworld | Branch W.R.,Bayworld | Braack H.,Abrus Environmental Consultancy | Manson M.,Golder Associates
Herpetology Notes | Year: 2010

The diet of metamorph Giant African Bullfrogs from a semi-aquatic habitat in the Karoo were recorded. All stomachs contained prey items; insects accounted for the greatest prey diversity, with Coleopterans (11 families) dominating the 29 insect families recorded. The most abundant prey items, none of which have previously been recorded in the diet, were a conchostracan "clam shrimp" (Leptestheriella cf. inermis), an aquatic snail (Physidae) and the small frog Cacosternum boettgeri. Metamorph bullfrogs had an average SUL of 39.3 mm and a mass of 5.19 g. After nine months, including a period of winter dormancy, the frogs had an average SUL of 81.4 mm and a mass of 71.38 g, equivalent to just over a doubling in SUL and a 1326% increase in mass. Source

Herrmann H.-W.,University of Arizona | Branch W.R.,Bayworld | Branch W.R.,Nelson Mandela Metropolitan University
Journal of Arid Environments | Year: 2013

Namibia is mostly an arid and semi-arid country with a high number of reptile and fewer amphibian species. We review the herpetological literature dealing with Namibian species over the past fifty years, and provide up-to-date amphibian and reptile accounts using a widely accepted taxonomy and nomenclature. We critically discuss species accounts, draw attention to the historical development of species inventories for the country, and indicate species endemism for Namibia and the Namib Desert. In Namibia, the lizard families Gekkonidae, Lacertidae, and Scincidae have undergone adaptive radiations and are species-rich. This also applies to the snake family Psammophiidae.Areas of herpetological research that have received most attention are systematics (with its disciplines faunistics (area inventories), taxonomy, and phylogeny), ecology, and physiology. The former is indicative of early stages of herpetological research such as area inventories and the subsequent analyzes of the collections. The latter two were largely enabled by (1) species highly adapted to life in the hyper-arid Namib Desert, and (2) by the accessibility of these species in the Namib Desert through the infrastructure provided by the Gobabeb Research and Training Center. The majority of the eco-physiological research has focused on three highly psammophilus, diurnal lizard species; Meroles anchietae, M. cuneirostris, and Gerrhosaurus skoogi, whilst diverse geckos form the basis of eco-morphological studies.The concentration of research localities around cities and the Gobabeb Research and Training Center is characteristic for opportunistic research. Geographic centers of herpetological research have been the central Namib Desert (i.e. Gobabeb), and areas around Swakopmund and Windhoek. Extensive parts of Namibia remain barely touched. Herpetological publication frequency has been approximately the same since its beginning in the early 1800's until the 1970's. The period between 1986 and 2003 experienced a remarkable increase of publication activity that has slightly subsided around 2004 and picked up again in recent years.Recent conservation related studies investigate the impact of overgrazing with land degradation and water related issues such as canals and hydroelectric dam projects on herpetological communities. In the near future the impact of mining, especially Uranium mining in the Namib Desert, and the effects of climate change with the predicted drying and warming will demand increased attention.Advances in biotechnology with ever-increasing amounts of data and decreasing cost have and will progressively enable advances in traditional disciplines like taxonomy, phylogeny, and systematics. Additionally, these technologies will increasingly empower the newer disciplines of molecular ecology and conservation biology in Namibia.Annotated, updated species checklists highlight Namibian and Namib diversity and endemicity, and also direct researchers to the numerous taxonomic problems that still confound full understanding of the region's herpetofauna. © 2012 Elsevier Ltd. Source

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