The niche-filling process predicted by the 'ecological opportunity' (EO) model is an often-invoked mechanism for generating exceptional diversity in island colonizers. Whether the same process governs lineage accumulation and... more
The niche-filling process predicted by the 'ecological opportunity' (EO) model is an often-invoked mechanism for generating exceptional diversity in island colonizers. Whether the same process governs lineage accumulation and trait disparity during continental colonization events is less clear. Here we test this prediction by investigating the rate dynamics and trait evolution of one of Africa's most widespread amphibian colonizers, the true toads (Bufonidae). By reconstructing the most complete molecular phylogeny of African Bufonidae to date, we find that the diversification of lineages in Africa best conforms to a constant rate model throughout time and across subclades, with little support for EO. Evolutionary rates of life history traits have similarly been constant over time. However, an analysis of generalists and specialists showed a shift towards higher speciation rates associated with habitat specialization. The overall lack of EO signal can be interpreted in a...
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The phylogenetic relationships of the African mongrel frog genus Nothophryne are poorly understood. We provide the first molecular assessment of the phylogenetic position of, and diversity within, this monotypic genus from across its... more
The phylogenetic relationships of the African mongrel frog genus Nothophryne are poorly understood. We provide the first molecular assessment of the phylogenetic position of, and diversity within, this monotypic genus from across its range-the Afromontane regions of Malawi and Mozambique. Our analysis using a two-tiered phylogenetic approach allowed us to place the genus in Pyxicephalidae. Within the family, Nothophryne grouped with Tomopterna, a hypothesis judged significantly better than alternative hypotheses proposed based on morphology. Our analyses of populations across the range of Nothophryne suggest the presence of several cryptic species, at least one species per mountain. Formal recognition of these species is pending but there is a major conservation concern for these narrowly distributed populations in an area impacted by major habitat change. The phylogenetic tree of pyxicephalids is used to examine evolution of life history, ancestral habitat, and biogeography of this...
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The tadpole of Leptopelis cf. grandiceps is described from the Uluguru Mountains of Tanzania. The tadpole resembles other Leptopelis tadpoles but differs from known East African Leptopelis tadpoles in having a divided first row (P1) of... more
The tadpole of Leptopelis cf. grandiceps is described from the Uluguru Mountains of Tanzania. The tadpole resembles other Leptopelis tadpoles but differs from known East African Leptopelis tadpoles in having a divided first row (P1) of infralabial keratodonts and in having more and longer oral papillae. There are furthermore pronounced differences in oral apparatus morphology between tadpoles of L. cf. grandiceps previously described from the Ukaguru Mountains and the material described here, which might indicate that the populations are in fact separate species. Tadpole morphology can provide additional characters that can contribute to taxonomic assessments and revisions.
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New data on Syrian amphibians and reptiles collected between 1990 and 2004 are given. The most important findings are the Elapid snake Walterinnesia aegyptia [now W. morgani], here reported for the first time from Syria; Zamenis... more
New data on Syrian amphibians and reptiles collected between 1990 and 2004 are given. The most important findings are the Elapid snake Walterinnesia aegyptia [now W. morgani], here reported for the first time from Syria; Zamenis hohenackeri and Vipera xanthina [sensu lato], previously known only from Mount Hermon, and the very rare and poorly known Telescopus nigriceps and Lytorhynchus kennedyi. Other specles were previously known from only a very few Syrian localities.
Peripatric speciation and peripheral isolation have uncertain importance in species accumulation, and are largely overshadowed by assumed dominance of allopatric modes of speciation. Understanding the role of different speciation... more
Peripatric speciation and peripheral isolation have uncertain importance in species accumulation, and are largely overshadowed by assumed dominance of allopatric modes of speciation. Understanding the role of different speciation mechanisms within biodiversity hotspots is central to understanding the generation of biological diversity. Here, we use a phylogeographic analysis of the spiny-throated reed frogs and examine sister pairings with unbalanced current distributional ranges for characteristics of peripatric speciation. We further investigate whether forest/grassland mosaic adapted species are more likely created through peripatric speciation due to instability of this habitat type. We reconstructed a multi-locus molecular phylogeny of spiny-throated reed frogs which we then combined with comparative morphologic data to delimit species and analyze historical demographic change; identifying three new species. Three potential peripatric speciation events were identified along wit...
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Excerpt: Both the fossil record and molecular dating show that most major squamate families were well established by the mid-Cretaceous and that a few stem lineages were present as early as the Jurassic (Kumazawa, 2007; Chapter 9). For... more
Excerpt: Both the fossil record and molecular dating show that most major squamate families were well established by the mid-Cretaceous and that a few stem lineages were present as early as the Jurassic (Kumazawa, 2007; Chapter 9). For example, skinks, cordylids and lacertids were present in the early Cretaceous or the late Jurassic (Vidal and Hedges, 2005, 2009), and gecko diversification is attributed to Gondwanan fragmentation in the early to mid-Cretaceous (Gamble et al., 2008). Chameleons (family Chamaeleonidae) however, are a young clade as compared with most other squamates. Together with Agamidae and Leiolepididae (collectively known as “acrodonts” ), they diverged from a common ancestor with the Iguanidae (“pleurodonts”) more than 120 Mya (Townsend et al., 2011a). Within the acrodonts, divergence between chameleons and the Leiolepididae / Agamidae occurred approximately 90 Mya (Kumazawa, 2007; Townsend et al., 2011a; Tolley et al., 2013). Although there is some uncertainty ...
The genus Leptopelis occurs in multiple habitats throughout sub-Saharan Africa, and it includes several species that have highly variable color patterns, which makes taxonomic studies challenging. In this study, we examined multiple... more
The genus Leptopelis occurs in multiple habitats throughout sub-Saharan Africa, and it includes several species that have highly variable color patterns, which makes taxonomic studies challenging. In this study, we examined multiple populations of Leptopelis from the Albertine Rift (AR), a region known for its high levels of endemism and biodiversity. Currently, five species are recognized from the AR: L. anebos, L. fiziensis, L. karissimbensis, L. kivuensis, and L. mtoewaate, most of which are found in and around the Itombwe Plateau in Democratic Republic of the Congo (DRC). We sampled 90 individuals of Leptopelis from multiple localities in DRC, Uganda, Rwanda and Burundi. We employed concatenated gene-tree analyses, coalescent species-tree analyses, and divergence dating approaches to infer phylogenies and biogeographic patterns with a multi-locus data set consisting of two mitochondrial (16S and cyt b) and one nuclear gene (RAG1). All analyses revealed several cryptic lineages within the genus, suggesting that a revision of AR Leptopelis taxonomy is needed.
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In 1931, Ernst Ahl described two species of reed frogs inhabiting montane forests of the Albertine Rift in East Africa, Hyperolius alticola and H. discodactylus, which were synonymized two decades later by Raymond Laurent. Since then,... more
In 1931, Ernst Ahl described two species of reed frogs inhabiting montane forests of the Albertine Rift in East Africa, Hyperolius alticola and H. discodactylus, which were synonymized two decades later by Raymond Laurent. Since then, this revision has been questioned repeatedly, but taxonomists have been reluctant to make a conclusive decision on the matter, especially since the type material of H. alticola was reported as being lost. Here, we examine the rediscovered type material of H. alticola and reassess the validity of Laurent's synonymy using morphological data from historic and new collections including all available type material, call recordings and molecular data from animals collected on recent expeditions. We find evidence for a northern and southern genetic clade, a divide that is somewhat supported by diverging morphology as well. However, no distinction in advertisement calls could be recovered to support this split and both genetic and morphological differences between geographic units are marginal and not always congruent and thus more likely reflect population-level variation. We therefore conclude that H. alticola is not a valid taxon and should continue to be treated as a synonym of H. discodactylus. Finally, we also report on newly collected material from outside the species known range, with first records of this species from Burundi.
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Torrent frogs of the genus Petropedetes Reichenow, 1874 as currently understood have a disjunct distribution with species endemic to West, Central or East Africa. We herein present a phylogenetic analysis including all but one of the... more
Torrent frogs of the genus Petropedetes Reichenow, 1874 as currently understood have a disjunct distribution with species endemic to West, Central or East Africa. We herein present a phylogenetic analysis including all but one of the currently described 12 species of the genus. Maximum Likelihood and Bayesian analyses of combined nuclear (rag1, SIA, BDNF) and mitochondrial (16S, 12S, cytb) genes of more than 3500 base pairs, revealed clades corresponding to the three sub-Saharan regions. Molecular results are confirmed by morphological differences. Surprisingly, the three geographic clades do not form a monophyletic group with respect to closely related families Pyxicephalidae and Conrauidae and therefore require taxonomic changes. We resurrect Arthroleptides Nieden, 1911 for the East African taxa. The Central African taxa remain in the genus Petropedetes. The West African members are placed in the new genus Odontobatrachus gen. nov. The taxonomic position of the new genus remains incertae sedis as it was not assigned to any of the four families included in our analyses. Potential new species have been detected within all three major clades, pointing to a still not fully clarified diversity within African torrent frogs.
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1 Sezione di Zoologia dei Vertebrati, Museo Tridentino di Scienze Naturali, Via Calepina 14, I38100 Trento, Italy 2 Udzungwa Mountains Monitoring Centre, c/o Udzungwa Mountains National Park, PO Box 99 Mang'ula, Tanzania 3 Tanzania... more
1 Sezione di Zoologia dei Vertebrati, Museo Tridentino di Scienze Naturali, Via Calepina 14, I38100 Trento, Italy 2 Udzungwa Mountains Monitoring Centre, c/o Udzungwa Mountains National Park, PO Box 99 Mang'ula, Tanzania 3 Tanzania Forest Conservation Group, PO Box ...
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Two new species of Callulina are described from the Nguru Mountains, one from the main Nguru South block (C. hanseni sp. nov.) and one from the outlying mountain fragment of the Nguru in Kanga Forest Reserve (C. kanga sp. nov.). The... more
Two new species of Callulina are described from the Nguru Mountains, one from the main Nguru South block (C. hanseni sp. nov.) and one from the outlying mountain fragment of the Nguru in Kanga Forest Reserve (C. kanga sp. nov.). The species are diagnosed based on a combination of morphological, acoustic and molecular data. An updated key to the species of all the known Callulina is provided. The conservation status of the two species is examined and, based on highly restricted distributions and ongoing ...