Anolis chrysolepis Duméril and Bibron, 1837 (Squamata: Iguanidae), Revisited: Molecular Phylogeny and Taxonomy of the Anolis chrysolepis Species Group

Revealing anole diversity in the highlands of the Northern Andes: New and resurrected species of the Anolis heterodermus species group

The Anolis heterodermus group comprises eight big-headed and short-legged lizard species from the highlands of the northernmost South American Andes. Recent studies revealed unknown lineages within this group that had previously been categorized as a species complex. By widely sampling and applying an integrative taxonomic framework, we (1) assessed the species diversity of the group using a molecular dataset (two mitochondrial and one nuclear markers) along with an inclusive morphological study (scalation, scale configuration and ornamentation, morphometrics, and dewlap and body colour patterns); and (2) we inferred the evolutionary relationships within this species group. Our analyses confirmed the formerly reported differentiation between populations of those high-altitude lizards, and we identified several unknown evolutionary lineages. Our results provided evidence for the existence of nine distinct, independently evolving evolutionary lineages in the heterodermus group. As a result, we described two morphologically and genetically highly distinct lineages as species new to science (A. quimbayasp. nov. and A. tequendamasp. nov.). We redescribed A. heterodermus and erected as a valid species Anolis richteri, a previously described synonym of A. heterodermus. A taxonomic key for the identification of species of the Phenacosaurus clade was presented. The identification of two additional poorly-known lineages suggested that the diversity of this group of lizards is still unknown; therefore, it is necessary to establish measurements for the group´s conservation, as well as to perform fieldwork and revision of herpetological collections to identify possible hidden diversity within the group.

Lizards on newly created islands independently and rapidly adapt in morphology and diet

Rapid adaptive changes can result from the drastic alterations humans impose on ecosystems. For example, flooding large areas for hydroelectric dams converts mountaintops into islands and leaves surviving populations in a new environment. We report differences in morphology and diet of the termite-eating gecko Gymnodactylus amarali between five such newly created islands and five nearby mainland sites located in the Brazilian Cerrado, a biodiversity hotspot. Mean prey size and dietary prey-size breadth were larger on islands than mainlands, expected because four larger lizard species that also consume termites, but presumably prefer larger prey, went extinct on the islands. In addition, island populations had larger heads relative to their body length than mainland populations; larger heads are more suited to the larger prey taken, and disproportionately larger heads allow that functional advantage without an increase in energetic requirements resulting from larger body size. Parallel morphological evolution is strongly suggested, because there are indications that, before flooding, relative head size did not differ between future island and future mainland sites. Females and males showed the same trend of relatively larger heads on islands, so the difference between island and mainland sites is unlikely to be due to greater male-male competition for mates on islands. We thus discovered a very fast (at most 15 y) case of independent parallel adaptive change in response to catastrophic human disturbance.

Phylogeny and diversity of neotropical monkey lizards (Iguanidae: Polychrus Cuvier, 1817)

Neotropical monkey lizards (Polychrus) are arboreal lizards with compressed bodies, partially fused eyelids and strikingly long, whip-like tails. The eight currently recognized species occur in the lowlands of South and Central America. Based on the largest taxon and character sampling to date, we analyze three mitochondrial and one nuclear gene using Bayesian methods to (1) infer the phylogeny of Polychrus under both concatenated-tree and species-tree methods; (2) identify lineages that could represent putative undescribed species; and (3) estimate divergence times. Our species tree places P. acutirostris as the sister taxon to all other species of Polychrus. While the phylogenetic position of P. gutturosus and P. peruvianus is poorly resolved, P. marmoratus and P. femoralis are strongly supported as sister to P. liogaster and P. jacquelinae, respectively. Recognition of P. auduboni and P. marmoratus sensu stricto as distinct species indicates that the populations of "P. marmoratus" from the Amazon and the Atlantic coast in Brazil represent separate species. Similarly, populations of P. femoralis from the Tumbes region might belong to a cryptic undescribed species. Relative divergence times and published age estimates suggest that the orogeny of the Andes did not play a significant role in the early evolution of Polychrus.

Hemipenial morphology and diversity in South American anoles (Squamata: Dactyloidae)

Hemipenial morphology has provided useful characters to improve species identification and phylogenetic relationships in squamates. Here we provide hemipenial description and illustration of 13 South American anoles. At generic and specific levels, differences are mainly related to shape and ornamentation; intraspecific variation is low. An asulcate process, present in the hemipenis of most anole species studied, was highly variable among species and may be a useful taxonomic character in hemipenial morphology of this group.

Phylogenetic relationships of Amazonian anole lizards (Dactyloa): taxonomic implications, new insights about phenotypic evolution and the timing of diversification

The ecology and evolution of Caribbean anoles are well described, yet little is known about mainland anole species. Lack of phylogenetic information limits our knowledge about species boundaries, morphological evolution, and the biogeography of anoles in South America. To help fill this gap, we provide an updated molecular phylogeny of the Dactyloa (Dactyloidae), with emphasis on the punctata species group. By sampling understudied Amazonian taxa, we (i) assess the phylogenetic placement of the 'odd anole', D. dissimilis; (ii) infer the relationships of the proboscis-bearing D. phyllorhina, testing the hypothesis of independent nasal appendage evolution within the anole radiation; and (iii) examine genetic and dewlap color variation in D. punctata and D. philopunctata. Combining multiple nuclear loci with a review of the fossil record, we also (iv) estimate divergence times within the pleurodont iguanian clade of lizards, including Amazonian representatives of Dactyloa and Norops (Dactyloidae) and of Polychrus (Polychrotidae). We recover the five Dactyloa clades previously referred to as the aequatorialis, heteroderma, latifrons, punctata and roquet species groups, as well as a sixth clade composed of D. dissimilis and the non-Amazonian D. neblinina and D. calimae. We find D. phyllorhina to be nested within the punctata group, suggesting independent evolution of the anole proboscis. We consistently recover D. philopunctata nested within D. punctata, and report limited genetic divergence between distinct dewlap phenotypes. The most recent common ancestor of Dactyloa, Anolis and Norops dates back to the Eocene. Most Amazonian taxa within both Dactyloa and Norops diverged in the Miocene, but some diversification events were as old as the late Eocene and late Oligocene. Amazonian Polychrus diverged in the Pliocene. Our findings have broad implications for anole biogeography, disputing recent suggestions that modern dactyloid genera were present in the Caribbean region during the Cretaceous.

Out of Florida: mtDNA reveals patterns of migration and Pleistocene range expansion of the Green Anole lizard (Anolis carolinensis)

Anolis carolinensis is an emerging model species and the sole member of its genus native to the United States. Considerable morphological and physiological variation has been described in the species, and the recent sequencing of its genome makes it an attractive system for studies of genome variation. To inform future studies of molecular and phenotypic variation within A. carolinensis, a rigorous account of intraspecific population structure and relatedness is needed. Here, we present the most extensive phylogeographic study of this species to date. Phylogenetic analyses of mitochondrial DNA sequence data support the previous hypothesis of a western Cuban origin of the species. We found five well-supported, geographically distinct mitochondrial haplotype clades throughout the southeastern United States. Most Florida populations fall into one of three divergent clades, whereas the vast majority of populations outside Florida belong to a single, shallowly diverged clade. Genetic boundaries do not correspond to major rivers, but may reflect effects of Pleistocene glaciation events and the Appalachian Mountains on migration and expansion of the species. Phylogeographic signal should be examined using nuclear loci to complement these findings.