Molecular phylogeny of Panaspis and Afroablepharus skinks (Squamata: Scincidae) in the savannas of sub-Saharan Africa

Abstract

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 95 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.

Multilocus phylogenetics in a widespread African anuran lineage (Brevicipitidae: Breviceps) reveals patterns of diversity reflecting geoclimatic change

“…Even if this cladogenic event occurred earlier and under different stimuli, the dramatic uplift (up to 1,000 m) almost certainly reinforced geographical separation. Furthermore, global cooling trends led to the fragmentation of pan‐African forest and promoted the emergence of savanna and grassland (Couvreur, Chatrou, Sosef, & Richardson, ; Zachos, Pagani, Sloan, Thomas, & Billups, ), which in turn has sculpted modern species distributions (Medina et al., ). Fossil and pollen records suggest widespread expansion of these habitats (coinciding with the shift from C3 to C4 grasses), rather than contraction, beginning in the Miocene (Jacobs, ; Sepulchre et al., ).…”

A new species of Rain Frog (Brevicipitidae, Breviceps) endemic to Angola

“…Unfortunately, this is not unique to the B. mossambicus group. Many recent studies on other herpetofauna have stated that large sampling gaps across sub-Saharan Africa may cause misleading biogeographic conclusions (Medina et al 2016;Jongsma et al 2018). The central and eastern localities of B. ombelanonga, as well as the latter from either B. adspersus or B. poweri, may be separated by drainage basins; however, with no contemporary sampling across regions spanning hundreds of kilometers, it is difficult to test these broad biogeographic hypotheses.…”

A Cryptic New Species of Polemon (Squamata: Lamprophiidae, Aparallactinae) from the Miombo Woodlands of Central and East Africa

“…Polemon ater inhabits southeastern Lualaba, Haut-Katanga, and Haut-Lomami provinces of DRC, and Zambia, which are dominated by grasslands and miombo woodlands ( de Witte, 1953;Broadley et al, 2003). Within Lualaba, Haut-Katanga, and Haut-Lomami provinces, plant species richness was highest within the miombo ecoregion (Broadley and Cotterill, 2004), and several unique species of reptiles are known from the region (e.g., Greenbaum et al, 2012;Medina et al, 2016). Polemon ater might have adapted to the miombo woodlands and savannas when arid climates in Africa increased after 9.6 mya (Feakins and DeMenocal, 2010).…”

“…Because of these factors, these habitats are constantly at risk, especially unprotected regions in southeastern DRC miombo woodlands and savannas (Sodhi et al, 2007;Herrmann and Branch, 2013). Additionally, southeastern DRC is known to harbor high species diversity of plants, amphibians, reptiles, and birds (Broadley and Cotterill, 2004;Greenbaum et al, 2012;Larson et al, 2016;Medina et al, 2016). Given the results herein and from Portillo et al (2018), it is likely that P. ater is endemic to the grasslands, miombo woodlands, and possibly forests of southeastern DRC, Zambia, and west-central Tanzania.…”