Species Of Liolaemus Research Articles

The skull of Liolaemus huayra compared to other species of Liolaemus and Phymaturus (Squamata, Liolaemidae).

Despite the extensive study of various aspects of the genus Liolaemus, there remains a scarcity of information regarding the osteology of species. In the last two decades, over 100 species have been described within the genus, but still less than 10% of the Liolaemus species includes any osteological data. In this study, we provide a description of the skull of Liolaemus huayra, a taxon closely related to the L. dorbignyi clade (a subset of the L. montanus group). The species was originally described in 2008 based on a few specimens from the Sierra de Quilmes, Tucumán. By obtaining new specimens from a nearby locality (La Ovejería, Catamarca), we were able to prepare the skulls of two males and two females specimens. Despite the limited sample size, we observed intra-specific variability in characters such as postorbital and nasal shape, as well as mandibular curvature. We also document some inter-specific differences based on the scarce osteological information available from other species within the genus. This description constitutes a significant contribution to the osteology of the Liolaemidae clade. We emphasize the importance of detailed descriptions that provide morphological characters suitable for inclusion in comprehensive phylogenetic analyses.

A new species of Liolaemus (Iguania: Liolaemidae) from the hot deserts of northern Patagonia, Argentina

A new species of Liolaemus is described from southwest of the town of Añelo, Neuquén Province, Argentina. Integrative evidence methodology of external morphological characters and molecular phylogenetic analyses of mitochondrial DNA (cyt-b) is used to place the new species to the species group of Liolaemus boulengeri. The new species is phenotypically close to L. mapuche. The new Liolaemus is medium to large in size (males 77.64–83.98 mm, females 72.88–78.58 mm), with evident sexual dichromatism. Genetic distances of the mtDNA (cyt-b) between the new species and its closest relative species are greater than 3% (L. cuyanus 7.48–12.02%; L. josei 7.56–9.60%; L. puelche 8.23–9.93%; L. mapuche 8.51–9.79%). Molecular and morphological phylogenetic results show L. mapuche as the sister species of the new one. The new species is larger than L. mapuche. Dorsal and ventral scales are more numerous in the new species than in L. mapuche, precloacal pores in females are present in L. mapuche and absent in the new species. It has strict psammophilic habits, using sand mounds and sheltering, under Alpataco (Neltuma alpataco) bushes. The L. boulengeri group now contains 75 species distributed in Argentina, Bolivia, Brazil, Chile, Paraguay, Peru and Uruguay.

The role of climate and maternal manipulation in determining and maintaining reproductive mode in Liolaemus lizards

AbstractEvolutionary transitions in life‐history strategies, such as the shift from egg‐laying to live birth (viviparity) are of great interest to evolutionary biologists. In squamate reptiles, several hypotheses have been proposed to explain viviparity including the cold climate hypothesis, maternal manipulation hypothesis, hypoxia hypothesis, and several others. We used two approaches: first we studied 45 species of Liolaemus, a genus where nearly 50% of species are viviparous, using a diverse ecophysiological dataset to examine the cold climate and maternal manipulation hypotheses. We collected environmental thermal data (accounting for elevational differences among species), physiological traits including preferred body temperature and its coefficient of variation as an indicator of precision in thermoregulation. Additionally, we collected standard metabolic rates for 23 of the 45 species. In one clade (the darwinii group of species) with both reproductive modes, we ran our second approach. We tested for differences in thermal physiology and metabolic rates between viviparous and oviparous species during pregnancy and non‐pregnancy periods. The cold climate hypothesis received strong support because viviparous species occur in sites with colder air temperatures (including areas at both higher elevations and latitudes) compared with oviparous species. Our detailed analysis showed that the maternal manipulation hypothesis also is supported; pregnant viviparous females show lower variation in their selected temperature. Our evidence suggests that the Andean orogeny is likely to have played a key role in the diversification of Liolaemus lizards and the evolution of viviparity in this clade may have been driven by a variety of physiological advantages accrued at different stages of embryogenesis and over evolutionary time. Thus, historical climate changes may have led to egg retention and may have been accompanied by other adaptations such as thermoregulation precision.

Liolaemus duellmani Cei, 1978 (Reptilia: Squamata: Liolaemini), redescription of the holotype and variation in a microendemic and inadequately known species of Liolaemus from Northwestern Patagonia

Liolaemus duellmani is a microendemic lizard described from southern Mendoza, Argentina, representing the southernmost distribution of the Liolaemus montanus species group. The original description was based on a small batch of preserved material and a juvenile collected alive. Along the years, this poorly known species was rarely collected or observed in the field, with no additional reports or findings published until a recent description of an adult female which was considered as a rediscovery of the species. Here, we redescribe the species and describe variation on external morphology, coloration, and some natural history observations.

Geographic variation in the matching between call characteristics and tympanic sensitivity in the Weeping lizard.

Effective communication requires a match among signal characteristics, environmental conditions, and receptor tuning and decoding. The degree of matching, however, can vary, among others due to different selective pressures affecting the communication components. For evolutionary novelties, strong selective pressures are likely to act upon the signal and receptor to promote a tight match among them. We test this prediction by exploring the coupling between the acoustic signals and auditory sensitivity in Liolaemus chiliensis, the Weeping lizard, the only one of more than 285 Liolaemus species that vocalizes. Individuals emit distress calls that convey information of predation risk to conspecifics, which may respond with antipredator behaviors upon hearing calls. Specifically, we explored the match between spectral characteristics of the distress calls and the tympanic sensitivities of two populations separated by more than 700 km, for which previous data suggested variation in their distress calls. We found that populations differed in signal and receptor characteristics and that this signal variation was explained by population differences in body size. No precise match occurred between the communication components studied, and populations differed in the degree of such correspondence. We suggest that this difference in matching between populations relates to evolutionary processes affecting the Weeping lizard distress calls.

Four Species Linked by Three Hybrid Zones: Two Instances of Repeated Hybridization in One Species Group (Genus Liolaemus)

Hybridization is an evolutionary process that can generate diverse outcomes, such as reinforcing species boundaries, generating new species, or facilitating the introgression of locally-adapted alleles into new genomic backgrounds.Liolaemusis a highly diverse clade of South American lizards with ~260 species and as many as ten new species are described each year. PreviousLiolaemusstudies have detected gene flow and introgression among species using phylogenetic network methods and/or through comparisons of nuclear and mitochondrial DNA patterns, yet no study has systematically studied hybrid zones betweenLiolaemusspecies. Here, we compared three hybrid zones between four species in theLiolaemus fitzingeriigroup of lizards in Central Argentina where two species,L. melanopsandL. xanthoviridis, each hybridize with two other species (L. shehuenandL. fitzingerii). We sampled three transects that were each ~120 km in length and sequenced both mitochondrial and genome-wide SNP data for 267 individuals. In our analyses of nuclear DNA, we also compared bi-allelic SNPs to phased alleles (50 bp RAD loci). Population structure analyses confirmed that boundaries separating species are sharp, and all clines are <65 km wide. Cline center estimates were consistent between SNPs and phased alleles, but cline width estimates were significantly different with the SNPs producing wider estimates. The mitochondrial clines are narrower and shifted 4–20 km southward in comparison to the nuclear clines in all three hybrid zones, indicating that either each of the species has sex-biased dispersal (males northward or females southward), the population densities are unequal, or that the hybrid zones are moving north over time. These comparisons indicate that some patterns of hybridization are similar across hybrid zones (mtDNA clines all narrower and shifted to the south), whereas cline width is variable. Hybridization in theL. fitzingeriigroup is common and geographically localized; further studies are needed to investigate whether hybrid zones act as hard species boundaries or promoters of speciation through processes such as reinforcement. Nonetheless, this study provides insights into both biotic and abiotic mechanisms helping to maintain species boundaries within the specioseLiolaemussystem.

Filling Linnean shortfalls increases endemicity patterns: conservation and biogeographical implications for the extreme case ofLiolaemus(Liolaemidae, Squamata) species

AbstractLinnean shortfalls, or the discrepancy between formally described species and the number of existing species, imply noteworthy biodiversity conservation constraints. The case of Argentinian reptiles is unique in this context. The genus Liolaemus represents ~60% of the Argentine reptile fauna and has a current species description rate of 3.25 spp./year, leading to a significant increase in the number of known species. Filling Linnean shortfalls within this genus has revealed an extraordinary recent evolutionary radiation that strongly modifies the spatial accumulation patterns of richness and endemism, mainly in the Patagonian steppe and Monte ecoregions of Argentina. Thus, while 40 years ago none of the studied species was considered endemic at the ecoregional level, today the genus represents an essential element to define the southernmost terrestrial ecoregions of the world. Furthermore, the remarkable decrease in the average extent of occurrence (EOO) of Liolaemus species implies an increased extinction risk in light of threats caused by humans. Based on the thresholds for the IUCN Red List B1 criteria, and 11 well-studied clades of Liolaemus, we show that, while in 1980 87% of the described species would not qualify as threatened based on EOO, today 80% of the species have an EOO smaller than 20 000 km2. Therefore, they may qualify as threatened based on the B1 EOO thresholds, which demonstrates the importance of the recent increase of knowledge regarding the taxonomy, systematics and genetics of the group.

Una nueva especie de lagartija del género Liolaemus (Iguania: Liolaemidae) endémica de la Puna del sur de Perú

The Andes of southern Peru contain a biodiversity with high degree of endemism due to itspeculiar geography and bioclimate. In this work a new endemic species of the genus Liolaemusis described which would be restricted to an altitude between 3870–4100 m s.n.m., in theSalado river basin of the district and province of Espinar, department of Cusco. This speciesis characterized by the unique combination of morphological characters and the color patternthat distinguish it from the rest of the species of the genus Liolaemus, mainly within of L. ortiziclade of the L. montanus group, where the new species is located according to our phylogenetichypothesis based on morphological evidence presented in this study.

Comentarios y adiciones sobre especies recientemente descritas del grupo Liolaemus montanus procedentes de Perú

In this paper, information is added and comments are made about two recently describedPeruvian species of Liolaemus from the montanus group: L. balagueri and L. qalaywa. WhenL. balagueri was described, differences from L. nazca was based on a phylogenetic analysis of asingle mitochondrial locus, but without including phenotypic diagnostic traits that might differentiatedthem. On the other hand, L. qalaywa description was based upon specimens fromApurimac department and intraspecific variation in meristic traits were missing. In this study,we added a molecular and morphological analyses between L. balagueri and L. nazca, supportingmore rigorously the separation between these two taxa. In addition, the geographic rangeof L. qalaywa is extended to Cusco department (southwestern Peru), intraspecific variation ofmorphological characteristics and geographic information up to 79 specimens are included,and the conservation issues of this species is commented.

Structure and comparative analysis of the mitochondrial genomes of Liolaemus lizards with different modes of reproduction and ploidy levels.

Liolaemus is the most specious genus of the Squamata lizards in South America, presenting exceptional evolutionary radiation and speciation patterns. This recent diversification complicates the formal taxonomic treatment and the phylogenetic analyses of this group, causing relationships among species to remain controversial. Here we used Next-Generation Sequencing to do a comparative analysis of the structure and organization of the complete mitochondrial genomes of three differently related species of Liolaemus and with different reproductive strategies and ploidy levels. The annotated mitochondrial genomes of ca. 17 kb are the first for the Liolaemidae family. Despite the high levels of sequence similarity among the three mitochondrial genomes over most of their lengths, the comparative analyses revealed variations at the stop codons of the protein coding genes and the structure of the tRNAs among species. The presence of a non-canonical dihydrouridine loop is a novelty for the pleurodonts iguanians. But the highest level of variability was observed in two repetitive sequences of the control region, which were responsible for most of the length heterogeneity of the mitochondrial genomes. These tandem repeats may be useful markers to analyze relationships of closely related species of Liolaemus and related genera and to conduct population and phylogenetic studies.

Correlated evolution between herbivory and gastrointestinal tract in a prolific lizard adaptive radiation

Abstract Radiations of ectothermic vertebrates across cold climates depend on the coordinated evolution of multiple traits that compensate for the constraints imposed by limited and fluctuating resources, such as temperature, food and oxygen. One of nature’s most prolific such radiations, Liolaemus lizards, has diversified across the extreme cold climates of the Andes and Patagonia. Remarkably, the prevailing patterns of reptile herbivory are opposed by Liolaemus which, in contrast with lizards generally, have repeatedly evolved plant consumption across small-bodied species from cold climates. Herbivory is hypothesized to depend on the evolution of multiple traits that maximize absorption of nutrients from an intrinsically poor-quality diet, such as increases in gastrointestinal tract size and increases in the density of nematodes in the intestine that may assist with plant digestion. Here, a comparative phylogenetic approach across Liolaemus species is implemented to test these hypotheses, which have only been investigated nonphylogenetically. Results reveal that intestine length increases consistently with increasing herbivory, whereas stomach size or nematode load are not associated with plant consumption. Body size plays no role in herbivory either. Consequently, this evidence places emphasis on the enlargement of the intestine to facilitate the evolution of herbivory in cold climates.

Redescription of Liolaemus robertmertensi, Hellmich 1964 (Iguania: Liolaemidae) with description of a new species

We redescribe Liolaemus robertmertensi and describe a new species of Liolaemus, the secondmost speciose lizard genus. These species belong to the L. robertmertensi group of the subgenusLiolaemus sensu stricto. In recent years, some newly identified populations were assignedto Liolaemus robertmertensi. We applied an integrative approach using morphological andphylogenetic evidence to determine the relationships among these populations and found oneto belong to a new species described here. We performed statistical analyses to differentiate L.robertmertensi and the new species from other species of the alticolor-bibronii group. The newspecies shows a set of character states that allows it to be distinguished from L. robertmertensiand from all other species of Liolaemus. Despite the description of this new species, the taxonomicstatus of many populations still remain unknown.

Las especies del género Liolaemus (Liolaemidae). Lista de taxones y comentarios sobre los cambios taxonómicos más recientes

Taxonomic lists are important tools for understanding biodiversity and they provide informationat different scales about the species distributed within a region; as such, they allow us tounderstand the identities of the species that compose a given supra-specific taxon. While listsof the species of the genus Liolaemus have been published over the past few decades, providingtaxonomic and systematic information, these lists are now outdated and the number of validspecies within the genus has fluctuated rapidly over time and many taxonomic changes havegone unregistered. Although there are alternative means to consult this information, thesesources have suffered from a number of involuntary errors as well as some arbitrary omissionsor inclusions that have affected the dynamics of species inventories. In this work, we presentthe most complete taxonomic enumeration of the species of Liolaemus to date, including theavailable names for all of the valid and invalid species associated with these taxonomic changes.We recognize a total of 283 valid species in Liolaemus, along with another 65 invalid names.Fifteen taxa are recognized as species inquirenda, eight as nomina dubia, and two as nomina nuda.We hope that the careful review of each case and the exhaustive literature review will make thiswork a primary reference on South America's most speciose lizard genus.

Historia y taxonomía: redescripción de Liolaemus andinus Koslowsky, 1895 y descripción de dos nuevas especies de Liolaemus (Iguania: Liolaemidae)

Due to lack of information about the precise type locality of Liolaemus andinus, and the subsequentloss of the type material, for a long-time various population of divergent morphologicalcharacteristics were assigned to this taxon, which caused the identification of the true L. andinusto become problematic. The present study started in 2004 and after sixteen years of research ofthe various populations assigned or related to this species, L. andinus is redescribed, a neotypeis assigned, and considerations on its probable provenance, and data on its biology and distributionare provided. Also, a hypothesis is presented on the provenance of L. andinus based onbiological and historical support evidence. The taxonomic position of populations that have beenassigned to and confused with L. andinus in the literature is determined, several of which haveaffinity with L. poecilochromus and L. rosenmanni. Morphology and molecular-based analysesperformed in this study allow us to describe two new Liolaemus species, previously confusedand identified as Liolaemus andinus. These new taxa inhabit the high Andes phytogeographicregion in Argentina, at altitudes above 3000 m a.s.l. One of these species is distributed in thesouthwest of Catamarca province and the other inhabits the central-western portion of LaRioja province. The most significant morphological differences between these new species andLiolaemus andinus are mainly the coloration pattern and some lepidosis characters related tonumber of scales.

Nuevas especies de Liolaemus para la herpetofauna de la provincia de La Rioja, Argentina

Three Liolaemus species are cited as new from La Rioja province. Two were found in a poorlyexplored area in the top of an isolated mountain system in the middle of the Dry Chaco andother from the eastern edge of a salt-pan basin in the southwest limit of the Chaco biogeographicformation. We also present an updated checklist of La Rioja lizards.

A new species of Liolaemus (Reptilia: Squamata) of the Liolaemus capillitas clade (Squamata, Liolaemini, Liolaemus elongatus-kriegi group) from Sierra de Velasco, La Rioja Province, Argentina.

A new species of the Liolaemus capillitas clade is described. Liolaemus galactostictos sp. nov. differs from other members of its group by a combination of morphological and molecular traits, in particular its black dorsal coloration pattern not found in any other Liolaemus species. Liolaemus galactostictos sp. nov. is only known from its type locality. This new species is found in rocky fields surrounded by grasslands on the top of the Velasco Mountains, a ¨sky island environment¨, in northwestern Argentina. As well as other members of its clade this species seems to be strictly saxicolous, viviparous and feeds on insects.

Neuroanatomy of the lumbosacral plexus in a highly diversified clade of South-American lizards. Evolution and phylogenetic implications.

Only few published studies that describe the neuroanatomy of lizards. Here, we describe the neuroanatomy of several Iguanian species belonging to three families (species of Liolaemus and Phymaturus belonging to Liolaemidae, Tropidurus and Stenocercus as representatives of Tropiduridae, and Diplolaemus as a representative of Leiosauridae). Based on Sudan Black B staining and conventional dissections, the neuroanatomy of the lumbosacral region is described. Among the most outstanding results is the existence of a neuronal pattern of the lumbosacral plexus characteristic of Liolaemidae. In addition, it was found that in the genus Liolaemus the lumbosacral plexus is composed of five pairs of spinal nerves while in Phymaturus, Tropidurus, Stenocercus and Diplolaemus is composed from five to six pairs of spinal nerves (from pre-sacral, sacral, and caudal vertebrae). We find differences in the origin of the spinal nerves that constitute the plexus. In some cases, the pattern of nerves involved includes even the caudal vertebrae. Variation among taxa related to the zeugopodial innervation is described, and the homology of these nervous branches is discussed. Sexual differences were found in some species studied. Based on our results and available literature, we found three different patterns of innervation of the zeugopodium. The major contribution of this study is to provide a detailed description of lumbosacral plexus nerves pathways from their origins at the vertebral column to the muscles that they innervate.

How and when melanic coloration is an advantage for lizards: the case of three closely-related species of Liolaemus

Body temperature affects various aspects of ectotherm biology. Reptiles, as ectotherms, gain and control their temperature mainly through behavioural adjustments, although some body traits may also be advantageous. According to the thermal melanism hypothesis (TMH) dark colour may be thermally advantageous in cold environments. Additionally, differences in thermoregulatory capacity may also affect performance. We analysed the role of melanism in the thermoregulation and sprint speed performance of three species of Liolaemus lizards from Argentinean Patagonia. Liolaemus shitan, L. elongatus and L. gununakuna are phylogenetically close, with similar body sizes and life history traits, but differ in their melanic colouration, L. shitan being the darkest and L. gununakuna the lightest species. We estimated sprint speed performance curves and heating rates, and recorded final body temperature and sprint speed achieved after a fixed heating time, from two different initial body temperatures, and with and without movement restriction. Performance curves were similar for all the species, but for L. gununakuna the curve was more flattened. Darker species showed faster heating rates, ran faster after fixed heating trials at the lowest temperature, and reached higher body temperatures than L. gununakuna, but this was compensated for by behavioural adjustments of the lighter lizards. Similarity of sprint speed performance may be due to the conservative nature of this character in these species, while variation in heating ability, particularly when starting from low temperatures, may reflect plasticity in this trait. The latter provides support for the TMH in these lizards, as melanism helps them increase their body temperature. This may be especially advantageous at the beginning of the day or on cloudy days, when temperatures are lower.

Description and phylogeny of a new species of Liolaemus (Iguania: Liolaemidae) endemic to the south of the Plurinational State of Bolivia.

The Liolaemus montanus group is a diverse group of lizards that ranges from central Peru to southwestern Mendoza, Argentina, including much of the Plurinational State of Bolivia (“Bolivia”) and Chile. The species of this group mainly inhabit high elevation areas with cold temperatures. In the last years, several species of this group have been described, mostly in Argentina and Chile. In Bolivia, there are at least thirteen valid species belonging to the L. montanus group. In this study, we describe a new species of the L. montanus group with a marked endemism in the Cordillera de Sama of the Tarija Department, Bolivia, and a combination of unique character states that allows its formal description as a new species. The phylogenetic relationships based on analysis of 159 morphological characters suggest that it belongs to the L. montanus group, and that it is closest to Liolaemus pulcherrimus, which is found allopatrically in a small area of the Jujuy Province, Argentina. The multivariate analyses of 66 morphological characters support the phylogenetic relationships. Statistical analyses of inter-species comparisons of morphological characters are not considered the only methods due to the non-independence of some characters states among species; thus, a phylogenetic analysis is recommended. The detailed revision of specimens of the L. montanus group held in the collections of Bolivia is filling major geographic gaps and improving our understanding of the phylogenetic and biogeographic relationships of this widely distributed group of South American lizards.

Solving the Liolaemus bibronii puzzle, an integrative taxonomy approach: redescription of L. bibronii and description of three new species (Iguania: Liolaemidae)

AbstractWe redescribe Liolaemus bibronii and describe three new species of Liolaemus, a genus of lizards distributed across South America. These species belong to the L. alticolor–bibronii group, which are included in the subgenus Liolaemus s.s. Liolaemus bibronii was previously proposed as a species complex, but many populations initially assigned to this complex were described as valid species. The three new species described here were populations denominated under L. bibronii. In order to validate the new species, we apply an integrative approach, including molecular and morphological evidence. Also, we perform phylogenetic analyses applying parsimony and Bayesian inference. The three new species described here show a set of character states that allow them to be distinguished from L. bibronii, from each other and from all other species of Liolaemus. Our phylogenies show that the newly described species are more related to other species than to L. bibronii. With this study, we are closer to solving the taxonomic puzzle that L. bibronii represents.