Date of Award
Doctor of Philosophy
The Subfamilies Aparallactinae (collared snakes) and Atractaspidinae (burrowing asps) occur in multiple habitats throughout sub-Saharan Africa, and they include multiple poorly studied genera. The monophyly of these groups are well established, but relationships within the subfamilies are poorly known. My study contains samples from six of eight aparallactine genera, and both atractaspidine genera in the Middle East and sub-Saharan Africa. I employed concatenated gene-tree analyses, divergence dating approaches, ancestral-area reconstructions, ancestral-state reconstructions, morphological analyses, and taxonomic assessments to infer phylogenies, biogeographic patterns, and evolutionary histories with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). Diversification occurred predominantly during the Miocene, with a few speciation events occurring during the Pliocene and Pleistocene. Biogeographic analyses suggested that the Zambezian biogeographic region composed of grasslands and woodlands, facilitated radiations, vicariance, and dispersal for many aparallactines. Moreover, the ranges of many forest species were fragmented during xeric and cooler conditions, thus aiding in diversification events. Biogeographic patterns of aparallactine and atractaspidine snakes were consistent with previous studies on other sub-Saharan herpetofauna. Ancestral-state reconstructions suggested the ancestor to collared snakes and burrowing asps was rear-fanged with a broad diet. Multiple fang types have rapidly evolved within burrowing asps, allowing these snakes to exploit specific prey items. Additionally, current classification of collared snakes and burrowing asps is insufficient; herein a taxonomic revision was conducted including the description of two new species, the first collared snakes to be described in over 40 years.
Received from ProQuest
Portillo, Francisco, "Systematics Of Collared Snakes And Burrowing Asps (aparallactinae And Atractaspidinae) (squamata: Lamprophiidae)" (2017). Open Access Theses & Dissertations. 731.