title: Evolutionary relationships, species delimitation and biogeography of Eastern Afromontane horned chameleons (Chamaeleonidae: Trioceros).
abstract: The Eastern Afromontane Region (EAR) contains numerous endemic species, yet its reptile diversity remains relatively poorly understood. We used molecular data to examine species diversity of the Sub-Saharan chameleon genus Trioceros. In particular, we focus on establishing species boundaries for taxa with disjunct distributions across the fragmented mountains of the EAR, including T. affinis, T. balebicornutus, T. deremensis, T. harennae, T. tempeli and T. werneri. We applied three species-delimiting approaches, General Mixed Yule-Coalescent (GMYC), a Bayesian implementation of the GMYC, and Bayes Factor Delimitation to estimate species diversity. Using a dated phylogeny, we also examined spatial and temporal diversification patterns in Trioceros. We found strong congruence between different species delimitation approaches, with all methods suggesting that species diversity is currently underestimated. In particular, T. werneri consists of at least four candidate species (i.e. species awaiting description) with some mountain ranges (Uluguru and Udzungwa) having potentially more than one species. Most interspecific divergences between extant Trioceros lineages are estimated to be >5Mya, consistent with a Pliocene origin of the endemic montane fauna, as exhibited in other taxonomic groups. Multiple, overlapping geographic events (climate and/or geomorphological changes) might account for speciation patterns in Trioceros given the dating results.
authors.affiliation: University of Basel, Biogeography Research Group, Department of Environmental Sciences, Basel 4056, Switzerland.
authors.forename: F Sara
authors.initials: FS
authors.lastname: Ceccarelli
authors.affiliation: Tropical Biodiversity Section, Science Museo of Trento, Via della Scienza e del lavoro, 38122 Trento, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Menegon
authors.affiliation: Applied Biodiversity Research Division, South African National Biodiversity Institute, Claremont 7735, Cape Town, South Africa; Department of Botany and Zoology, Stellenbosch University, Matieland 7602, South Africa.
authors.forename: Krystal A
authors.initials: KA
authors.lastname: Tolley
authors.affiliation: Department of Botany and Zoology, Stellenbosch University, Matieland 7602, South Africa.
authors.forename: Colin R
authors.initials: CR
authors.lastname: Tilbury
authors.affiliation: Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Gower
authors.affiliation: University of Basel, Biogeography Research Group, Department of Environmental Sciences, Basel 4056, Switzerland.
authors.forename: Maiti H
authors.initials: MH
authors.lastname: Laserna
authors.affiliation: Ethiopian Wildlife Conservation Authority, P.O. Box 386, Addis Ababa, Ethiopia.
authors.forename: Roman
authors.initials: R
authors.lastname: Kasahun
authors.affiliation: Tropical Biodiversity Section, Science Museo of Trento, Via della Scienza e del lavoro, 38122 Trento, Italy.
authors.forename: Ana
authors.initials: A
authors.lastname: Rodriguez-Prieto
authors.affiliation: University of Basel, Biogeography Research Group, Department of Environmental Sciences, Basel 4056, Switzerland.
authors.forename: Reto
authors.initials: R
authors.lastname: Hagmann
authors.affiliation: University of Basel, Biogeography Research Group, Department of Environmental Sciences, Basel 4056, Switzerland. Electronic address: simon.loader@unibas.ch.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Loader
mesh_terms: D017954:Africa South of the Sahara; D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D002980:Climate; D016013:Likelihood Functions; D008116:Lizards / Q000145:classification* / Q000235:genetics; D008957:Models, Genetic; D010802:Phylogeny; D017422:Sequence Analysis, DNA
keywords: Africa; Ancestral areas; Biodiversity; Ethiopia; Squamata; Tanzania