Matthew P. Heinicke

Major Caribbean and Central American frog faunas originated by ancient oceanic dispersal

Approximately one-half of all species of amphibians occur in the New World tropics, which includes South America, Middle America, and the West Indies. Of those, 27% (801 species) belong to a large assemblage, the eleutherodactyline frogs, which breed out of water and lay eggs that undergo direct development on land. Their wide distribution and mode of reproduction offer potential for resolving questions in evolution, ecology, and conservation. However, progress in all of these fields has been hindered by a poor understanding of their evolutionary relationships. As a result, most of the species have been placed in a single genus, Eleutherodactylus, which is the largest among vertebrates. Our DNA sequence analysis of a major fraction of eleutherodactyline diversity revealed three large radiations of species with unexpected geographic isolation: a South American Clade (393 sp.), a Caribbean Clade (171 sp.), and a Middle American Clade (111 sp.). Molecular clock analyses reject the prevailing hypothesis that these frogs arose from land connections with North and South America and their subsequent fragmentation in the Late Cretaceous (80–70 Mya). Origin by dispersal, probably over water from South America in the early Cenozoic (47–29 million years ago, Mya), is more likely.

A new frog family (Anura: Terrarana) from South America and an expanded direct-developing clade revealed by molecular phylogeny

Three frogs of a new species found in cloud forests on two nearby mountains in Guyana were included in a molecular phylogeny of 17 nuclear and mitochondrial genes (10,739 aligned sites) that revealed that their closest relative is Terrarana (Brachycephalidae, Craugastoridae, Eleutherodactylidae, and Strabomantidae) and their next-closest relative is Hemiphractidae (marsupial frogs). We place these frogs in a new family, genus, and species which is strongly supported as the basal clade within Terrarana: Ceuthomantidae n. fam., Ceuthomantis smaragdinus n. gen, n. sp. Morphological evidence supports the placement of two other species from the Guiana Highlands, Pristimantis aracamuni (BarrioAmoros & Molina) and P. cavernibardus (Myers & Donnelly), in the new family and genus. This close phylogenetic relationship of terraranans and marsupial frogs, nearly all of which have direct development, supports an hypothesis that direct development evolved early in the evolution of this huge clade (~1000 species), for which we propose the unranked taxonomic epithet Orthobatrachia.

Phylogeny of a trans-Wallacean radiation (Squamata, Gekkonidae, Gehyra) supports a single early colonization of Australia

Heinicke, M. P., Greenbaum, E., Jackman, T. R. & Bauer, A. M. Phylogeny of a trans‐Wallacean radiation (Squamata, Gekkonidae, Gehyra) supports a single early colonization of Australia. —Zoologica Scripta, 40, 584–602.

Phylogeny of bent-toed geckos (Cyrtodactylus) reveals a west to east pattern of diversification.

The Asian/Pacific genus Cyrtodactylus is the most diverse and among the most widely distributed genera of geckos, and more species are continually being discovered. Major patterns in the evolutionary history of Cyrtodactylus have remained largely unknown because no published study has broadly sampled across the geographic range and morphological diversity of the genus. We assembled a data set including sequences from one mitochondrial and three nuclear loci for 68 Cyrtodactylus and 20 other gekkotan species to infer phylogenetic relationships within the genus and identify major biogeographic patterns. Our results indicate that Cyrtodactylus is monophyletic, but only if the Indian/Sri Lankan species sometimes recognized as Geckoella are included. Basal divergences divide Cyrtodactylus into three well-supported groups: the single species C. tibetanus, a clade of Myanmar/southern Himalayan species, and a large clade including all other Cyrtodactylus plus Geckoella. Within the largest major clade are several well-supported subclades, with separate subclades being most diverse in Thailand, Eastern Indochina, the Sunda region, the Papuan region, and the Philippines, respectively. The phylogenetic results, along with molecular clock and ancestral area analyses, show Cyrtodactylus to have originated in the circum-Himalayan region just after the Cretaceous/Paleogene boundary, with a generally west to east pattern of colonization and diversification progressing through the Cenozoic. Wallacean species are derived from within a Sundaland radiation, the Philippines were colonized from Borneo, and Australia was colonized twice, once via New Guinea and once via the Lesser Sundas. Overall, these results are consistent with past suggestions of a Palearctic origin for Cyrtodactylus, and highlight the key role of geography in diversification of the genus.

Origin of invasive Florida frogs traced to Cuba

Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent.

Evolution of gliding in Southeast Asian geckos and other vertebrates is temporally congruent with dipterocarp forest development

Gliding morphologies occur in diverse vertebrate lineages in Southeast Asian rainforests, including three gecko genera, plus frogs, snakes, agamid lizards and squirrels. It has been hypothesized that repeated evolution of gliding is related to the dominance of Asian rainforest tree floras by dipterocarps. For dipterocarps to have influenced the evolution of gliding in Southeast Asian vertebrates, gliding lineages must have Eocene or later origins. However, divergence times are not known for most lineages. To investigate the temporal pattern of Asian gliding vertebrate evolution, we performed phylogenetic and molecular clock analyses. New sequence data for geckos incorporate exemplars of each gliding genus (Cosymbotus, Luperosaurus and Ptychozoon), whereas analyses of other vertebrate lineages use existing sequence data. Stem ages of most gliding vertebrates, including all geckos, cluster in the time period when dipterocarps came to dominate Asian tropical forests. These results demonstrate that a gliding/dipterocarp correlation is temporally viable, and caution against the assumption of early origins for apomorphic taxa.

Phylogeny, taxonomy and biogeography of a circum-Indian Ocean clade of leaf-toed geckos (Reptilia: Gekkota), with a description of two new genera

Geckos with a leaf-toed morphology (digits with a single pair of enlarged adhesive pads located terminally) occur on six continents and many islands. Although most leaf-toed gecko genera belong to independently derived lineages, recent studies support the monophyly of a circum-Indian Ocean group including four genera from disparate regions: the southern African genera Afrogecko and Cryptactites, the Malagasy genus Matoatoa, and the Australian genus Christinus. We obtained molecular and/or morphological data for most species in these genera to estimate phylogenetic relationships among constituent species and infer broad historical biogeographic patterns. Our results confirm that Afrogecko is not monophyletic, and that Christinus is embedded among African taxa. Afrogecko is comprised of three lineages, each of which is distinct in external features and osteology. Based on these results, we partition Afrogecko and recognize two new genera. Molecular clock analyses suggest divergences within the circum-Indian Ocean group are too recent for Gondwanan vicariance or hypothesized land bridges (e.g. Kerguelen Plateau) to account for the observed Africa/Madagascar/Australia distributional pattern. Ancestral area analyses support an origin of the clade in mainland Africa or Madagascar, and imply a dispersal event from southern Africa to Australia, similar to those observed in some plant and arthropod taxa, but otherwise unknown among non-volant terrestrial vertebrates. Dispersal was likely via a southern route and may have been facilitated by island hopping using Antarctica or other southern landmasses available in the mid-Cainozoic. http://zoobank.org/urn:lsid:zoobank.org:pub:7706B624-CD49-45CC-9DA3-FAB370BEE12B).

Phylogenomic support for evolutionary relationships of New World direct-developing frogs (Anura: Terraranae)

Phylogenomic approaches have proven able to resolve difficult branches in the tree of life. New World direct-developing frogs (Terraranae) represent a large evolutionary radiation in which interrelationships at key points in the phylogeny have not been adequately determined, affecting evolutionary, biogeographic, and taxonomic interpretations. We employed anchored hybrid enrichment to generate a data set containing 389 loci and >600,000 nucleotide positions for 30 terraranan and several outgroup frog species encompassing all major lineages in the clade. Concatenated maximum likelihood and coalescent species-tree approaches recover nearly identical topologies with strong support for nearly all relationships in the tree. These results are similar to previous phylogenetic results but provide additional resolution at short internodes. Among taxa whose placement varied in previous analyses, Ceuthomantis is shown to be the sister taxon to all other terraranans, rather than deeply embedded within the radiation, and Strabomantidae is monophyletic rather than paraphyletic with respect to Craugastoridae. We present an updated taxonomy to reflect these results, and describe a new subfamily for the genus Hypodactylus.

The measure of success: geographic isolation promotes diversification in Pachydactylus geckos

BackgroundGeckos of the genus Pachydactylus and their close relatives comprise the most species-rich clade of lizards in sub-Saharan Africa. Many explanations have been offered to explain species richness patterns of clades. In the Pachydactylus group, one possible explanation is a history of diversification via geographic isolation. If geographic isolation has played a key role in facilitating diversification, then we expect species in more species-rich subclades to have smaller ranges than species in less diverse subclades. We also expect traits promoting geographic isolation to be correlated with small geographic ranges. In order to test these expectations, we performed phylogenetic analyses and tested for correlations among body size, habitat choice, range sizes, and diversification rates in the Pachydactylus group.ResultsBoth body size and habitat use are inferred to have shifted multiple times across the phylogeny of the Pachydactylus group, with large size and generalist habitat use being ancestral for the group. Geographic range size is correlated with both of these traits. Small-bodied species have more restricted ranges than large-bodied species, and rock-dwelling species have more restricted ranges than either terrestrial or generalist species. Rock-dwelling and small body size are also associated with higher rates of diversification, and subclades retaining ancestral conditions for these traits are less species rich than subclades in which shifts to small body size and rocky habitat use have occurred. The phylogeny also illustrates inadequacies of the current taxonomy of the group.ConclusionsThe results are consistent with a model in which lineages more likely to become geographically isolated diversify to a greater extent, although some patterns also resemble those expected of an adaptive radiation in which ecological divergence acts as a driver of speciation. Therefore, the Pachydactylus group may represent an intermediate between clades in which radiation is adaptive versus those in which it is non-adaptive.

A New Species of the Pachydactylus weberi Complex (Reptilia: Squamata: Gekkonidae) from the Namibrand Reserve, Southern Namibia

Abstract A new species of gecko of the Pachydactylus weberi complex is described from the NamibRand Reserve in southern Namibia. It is morphologically well differentiated from all other members of this group, in lacking thigh tubercles, and can further be distinguished by its small size (< 45 mm snout–vent length), participation of the first supralabial in the nostril rim, snout scales much larger than interorbital scales, and three body bands in juveniles and adults. It has a distinctive, bold, contrasting hatchling coloration that superficially resembles that of P. mclachlani, from which it is distinguished both morphologically and genetically. DNA sequence data from two nuclear genes (RAG-1, PDC) and the ND2 mitochondrial gene plus its five flanking tRNAs (2,975 bp) reveal that this new species is most closely related, among the taxa sampled, to P. monicae from the lower Orange River valley.