Speciation across mountains: Phylogenomics, species delimitation and taxonomy of the Liolaemus leopardinus clade (Squamata, Liolaemidae).

Organisms rapidly diversifying across unstable environments such as mountain tops provide substantial challenges for resolving evolutionary histories and delimiting species. The Liolaemus leopardinus clade is a group of five species of lizards adapted to high altitudes in central Chile, with most species found in the Andes, but one species, L. frassinettii is found in the independent Costa Cordillera. Despite their allopatric distributions, they display shallow mitochondrial divergences, making phylogenetics and species delimitation of this clade hard to resolve. We use an integrative approach to delimit species by considering morphological data (linear and landmark-based), mitochondrial DNA (mtDNA), and nuclear DNA (Sequences and SNPs collected with ddRADseq). We find strong conflicting signals between phylogenetic analyses of the nuclear and mtDNA data. While mtDNA places L. frassinettii as sister to the rest of the clade, the SNPs support a south to north order of divergences, with southernmost species (new taxon described here) as sister to the rest of the clade. Moreover, species delimitation using mtDNA only supports two species (one in the Costa and one in the Andes), whereas combined analyses using the nuclear data and morphology support multiple Andean taxa, including a new one we describe here. Based on these results, population structure analyses and our knowledge of the geological and climatic history of the Andes, we argue that this mito-nuclear discordance is explained by past introgression among the Andean taxa, likely during glacial periods that forced these lizards to lower altitudes where they would hybridize. The complete isolation between the Costa and Andes cordilleras has prevented any further contact between taxa on either mountain chain. Our study highlights the importance of using multiple lines of evidence to resolve evolutionary histories, and the potential misleading results from relying solely on mtDNA.

A systematic review of parasites and micropredators of non-avian reptiles (Reptilia=Sauropsida) in Chile.

Knowledge about the identity of parasites in vertebrates is relevant because of their influence on ecological processes and health of their hosts. This is particularly important for groups of animals currently facing conservation issues, such as reptiles. The diversity of species and supra-specific taxa of microparasites and macroparasites (such as helminths and arthropods) present in non-avian reptiles in Chile was analyzed through a systematic review. A total of 49 scientific documents (thesis projects, abstracts in congresses, book chapters and peer-reviewed articles) concerning parasites, taxonomic descriptions and parasite ecology were included in this review. The suborder Iguania was among the most studied group with 35 native species recognized as hosts of parasites and 39 species of parasites reported up to the category of species or genus. Liolaemus tenuis was the species with the most taxa of recorded parasites (11 taxa, and only three to species level), but Liolaemus chillanensis had the highest number of identified species of parasites. In addition, only one native species of Serpentes, one of Gymnophthalmoidea, and two of Gekkota, as well as some reports of exotic species, were recorded as hosts. Among parasites, Trombidiformes was the richest order with 10 species from the superfamily Pterygosomatoidea and 16 species from Trombiculoidea. Current knowledge about the richness of helminths is very limited and there were only a few records of microparasites. In general, there is an urgent need for the development of collaborative works between specialists in reptile taxonomy and epidemiology in parasitology destined to evaluate the consequences that reptiles and their parasites will suffer due to the ongoing processes of habitat loss, climate change and the still present taxonomic issues of the native reptiles.

The missing leopard lizard: Liolaemus ubaghsi sp. nov., a new species of the leopardinus clade (Reptilia: Squamata: Liolaemidae) from the Andes of the O'Higgins Region in Chile.

Liolaemus is an extremely species rich genus of iguanid lizards from southern South America. Most of the diversity though is found in the Andes Cordillera, between Argentina and Chile. Here we describe Liolaemus ubaghsi sp. nov., from El Teniente Mine, in the Andean mountains of the O'Higgins Region in Chile. This species presents scalation and pattern traits that belong to the leopardinus clade, a group of viviparous, high altitude lizards that inhabit the mountain ranges surrounding Santiago City. The species of this clade in turn belong to the Andean and Patagonian elongatus-kriegi complex. Liolaemus ubaghsi sp. nov. has been previously recognized as L. leopardinus and L. elongatus, nevertheless we present diagnostic traits that allow us to describe it as a new species. It mainly differs from the rest of the leopardinus clade (L. leopardinus, L. ramonensis, L. valdesianus and L. frassinettii) by having the following unique combination of traits: ochre background coloration, a wide dark occipital stripe, dark flanks, white dots dispersed on the dorsum, absence of leopard-like spots and enlarged infralabial scales. 

On the identity of Liolaemus nigromaculatus Wiegmann, 1834 (Iguania, Liolaemidae) and correction of its type locality.

In the current study, we review the taxonomic status of Liolaemus nigromaculatus. Despite being the nominal species of the nigromaculatus group and being the second species of the genus Liolaemus that was described, this species is of uncertain type locality and its true identification is a matter of discussion. After carefully analyzing several digital pictures of the holotype (juvenile male), reviewing all of the literature concerning the issue, examining specimens of nearly all recognized species of the nigromaculatus group, and determining the locations visited by the specimen collector, we are able to point out the following: 1) Liolaemus nigromaculatus was collected between Puerto Viejo and Copiapó of the Atacama region in Chile, and not in Huasco 2) Liolaemus bisignatus is a nomen nudum, and populations attributed to Liolaemus bisignatus should be referred to as Liolaemus nigromaculatus. 3) There is agreement that Liolaemus copiapoensis is indistinguishable from populations currently referred to as Liolaemus bisignatus (= Liolaemus nigromaculatus), 4) Populations found in Huasco (currently considered the type locality of Liolaemus nigromaculatus) are very similar to those found in Caldera (currently considered Liolaemus bisignatus) and should be designated as Liolaemus nigromaculatus, and 5) Liolaemus oxycephalus and Liolaemus inconspicuus are not synonymous with Liolaemus nigromaculatus, although their true identities are difficult to determine. We also detail several characteristic based on the holotype of Liolaemus nigromaculatus, in addition to drawing diagnostic comparisons between this species and others belonging to the nigromaculatus group.

Deep Divergences within Liolaemus nigroviridis (Squamata, Liolaemidae) Lineages Associated with Sky Islands in Central Chile.

Evolution of montane species may be strongly influenced by climate oscillations, particularly species distributed in isolated high-elevation areas (sky islands). Chilean topography is exemplified by montane environments including the Andes and Coastal Mountains. To test hypotheses related to genetic divergence associated with sky islands, we explored population genetics and phylogenetic signatures in the montane lizard Liolaemus nigroviridis Müller and Hellmich 1932. We sequenced the mitochondrial cytochrome b for samples collected from six montane areas in central Chile. We found high genetic divergence among populations, congruent with well-supported clades from phylogeny reconstructions. The most recent common ancestor of all samples of L. nigroviridis was dated around the limit of Pliocene-Pleistocene (2.7 Mya), congruent with early vicariance of Andean and coastal populations. Deep lineage divergences suggest that allopatric populations accumulated high nucleotide differences and maintained long periods without gene exchange. We discuss potential taxonomic revisions considering relative genetic divergence.