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.

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.

Una nueva especie de Liolaemus (Iguania: Liolaemidae) perteneciente al grupo L. montanus en las lomas costeras del sur de Perú

El género Liolaemus presenta una gran diversidad entre los tetrápodos actuales, al punto de corresponder al segundo género con mayor número de especies válidas descritas del infraorden Iguania. En este trabajo, se describe una nueva especie de lagartija arenícola perteneciente al subgénero Eulaemus, grupo de Liolaemusmontanus, procedente de las lomas costeras de Quilca, La Chira y Ocoña, todos en la provincia de Camaná, departamento de Arequipa, Perú. Para determinar el estatus taxonómico de esta nueva especie, analizamos los caracteres morfológicos, moleculares y geográficos. Los caracteres morfológicos permitieron la caracterización y diagnóstico de la nueva especie, los moleculares fueron utilizados para realizar una inferencia bayesiana y los geográficos para determinar potenciales áreas de distribución. Este reptil se diferencia de las otras especies del grupo Liolaemusmontanus en su tamaño pequeño a mediano, su conjunto de caracteres morfológicos, folidosis y patrón de coloración: es la única especie del género donde los machos tienen un patrón de manchas laterales de forma redondeada con borde oscuro e interior verde desde las axilas hasta la mitad del cuerpo. Del mismo modo, los resultados filogenéticos moleculares realizados con el gen Cyt-b indican que no tiene relación directa con las especies fenéticamente similares descritas para el grupo. Sin embargo, existe una relación con poblaciones geográficamente cercanas que permanecen taxonómicamente innominadas. Finalmente, se determinó que esta lagartija tiene un endemismo muy marcado y sus poblaciones son poco abundantes.

The genus Liolaemus presents great diversity among the current tetrapods. It is the second genus with the highest number of valid species described of the Iguana infraorder. In this study, we described a new species of sand lizard from the coastal lomas of Quilca, La Chira and Ocoña that belongs to the subgenus Eulaemus and group of Liolaemus montanus, all in the province of Camaná, department of Arequipa, Peru. To determine the taxonomic status of this new organism, we analyzed morphological, molecular and geographical characters. The morphological characters allowed the characterization and diagnosis of the new species, the molecular data was used to make a Bayesian inference, and the geographic data served to determine potential distribution areas. This lizard diverges from the other species of the Liolaemus montanus group for its small to medium size, several sets of morphological characters, folidosis and color pattern. It is also the only species of the genus where the males have a pattern of lateral spots of rounded shape with dark border and green interior, from the armpits to the middle of the body. Additionally, the molecular phylogenetic results made with the Cyt-b gene indicate that it has no direct relationship with the phenetically similar species described for the group; nevertheless, there is a relationship with geographically close populations, which has not been properly described. Finally, it was determined that this lizard has a very marked endemism and its populations are not abundant.

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.

Study of lipid reserves in Liolaemus koslowskyi (Squamata: Liolaemidae): reproductive and ecological implications.

In reptiles, many lipid reserve structures were recognized, and different patterns of storage and utilization of lipids have been identified. In this study, a population of Liolaemus koslowskyi was studied to analyze the diversity and functioning of the lipid reserve structures. The specific objectives were to identify the main lipid reserve structures, and to describe their seasonal patterns; to study sexual and seasonal variations of the reserve structures; and to analyze the relation between seasonal patterns of such reserves with the sexual cycle and other biological aspects. Individuals of both sexes collected at five different times of the year were analyzed. The abdominal fat bodies, livers, tails, fat deposits of the lateral folds of the neck, the fat bodies of the axillary region and gonads were weighted. The fat content of livers, tails and neck fat reserves were determined through the extraction in a Soxhlet device. The volume of the ovaries, oviductal oocytes and testicles, and the average surface and thickness of the epididymides were estimated. The abdominal fat bodies and the tail-extracted fats were the main lipid reserves. In general, females showed higher lipid contents, and significant seasonal variations in weight and lipid content in both sex were found, while seasonal variations in the liver fresh weight and liver fat content were found only in males. The axillar and neck fats deposits probably function as auxiliary reserves, and the caudal autotomy did not significantly affect tail fat content. The sexual cycles were synchronic in both sexes.

Effect of body mass and melanism on heat balance in Liolaemus lizards of the goetschi clade.

The body temperature of ectotherms depends on the environmental temperatures and behavioral adjustments, but morphology may also have an effect. For example, in colder environments, animals tend to be larger and to show higher thermal inertia, as proposed by Bergmann's rule and the heat balance hypothesis (HBH). Additionally, dark coloration increases solar radiation absorption and should accelerate heat gain (thermal melanism hypothesis, TMH). We tested Bergmann's rule, the HBH and the TMH within the ITALIC! Liolaemus goetschilizard clade, which shows variability in body size and melanic coloration. We measured heating and cooling rates of live and euthanized animals, and tested how morphology and color affect these rates. Live organisms show less variable and faster heating rates compared with cooling rates, suggesting behavioral and/or physiological adjustments. Our results support Bergmann's rule and the HBH, as larger species show slower heating and cooling rates. However, we did not find a clear pattern to support the TMH. The influence of dorsal melanism on heating by radiation was masked by the body size effect in live animals, and results from euthanized individuals also showed no clear effects of melanism on heating rates. Comparison among three groups of live individuals with different degrees of melanism did not clarify the influence of melanism on heating rates. However, when euthanized animals from the same three groups were compared, we observed that darker euthanized animals actually heat faster than lighter ones, favoring the TMH. Although unresolved aspects remain, body size and coloration influenced heat exchange, suggesting complex thermoregulatory strategies in these lizards, probably regulated through physiology and behavior, which may allow these small lizards to inhabit harsh weather environments.

New Patagonian species of Liolaemus (Iguania: Liolaemidae) and novelty in the lepidosis of the southernmost lizard of the world: Liolaemus magellanicus.

We describe a new species within the genus Liolaemus from southeast Argentine Patagonia. This new taxon, Liolaemus yatel sp. nov., presents anatomical traits shared with the Liolaemus lineomaculatus section within the Liolaemus lineomaculatus group, especially the absence of precloacal pores in both sexes. However, Liolaemus yatel sp. nov. does not exhibit trifid dorsal scales, which is a diagnostic character of the L. lineomaculatus group. Moreover, this new species differs from other taxa of the L. lineomaculatus group in that dorsal and nuchal scales either completely lack keels or are slightly keeled. We also report, for the first time, the presence of trifid scales in Liolaemus magellanicus, another species included in the L. lineomaculatus section but constituting an independent lineage regarding the L. lineomaculatus group. The phenotypic traits of L. yatel sp. nov. and the presence of trifid scales in L. magellanicus provide additional information for the study of evolutionary relationships among the species of the L. lineomaculatus section, especially the establishment of their diagnostic character states.

Nuevo Liolaemus (Iguania: Liolaemidae) con novedoso carácter morfológico, de la frontera entre Argentina y Chile / New Liolaemus (Iguania: Liolaemidae) with a new morphological character from the border between Argentina and Chile

Liolaemus belongs to the Eulaemus subgenus, that is included in the Liolaemus montanus group or section, and is distributed in Argentina, Bolivia, Chile and Peru. The species members of this clade inhabit arid and high altitude environments, usually above 2 800m, and have a strong tendency to herbivory and a viviparous reproductive type. In a herpetological expedition to the Salta Province highlands, Argentina, in April 2012, we collected individuals of this new species for their description. The specimens were collected with loop, slaughtered by anesthesia and deposited in the herpetological collection of Fundación Miguel Lillo in Tucumán (FML). To characterize this new taxon, we analyzed 144 external morphological characters, referring primarily to lepidosis, color pattern, and body proportions, comparing with data from 66 constituent species of the L. montanus group (45 taxa from collection specimens and 21 from literature). Description of the colors in life was made in the field and based on photographs taken during the capture. The species described in this work inhabits a very narrow mountain range area in Salta Province (Argentina), and the Atacama Region (Chile), always above the 3 600m. This new taxon shows characteristics of lepidosis and color patterns clearly different from the other species members of the L. montanus group: the maximum snout-vent length is 72.9mm; shows 74-96 scales around midbody, 89-104 dorsal scales between the occiput and hind limbs, 92-109 ventrals, precloacal pores are evident in both, males and females, and supernumerary pores in males. Also, the presence of postcloacal pores stands out as unique among all Liolaemus. This is a new character, not only for the genus, but also to all Reptilia, becoming a morphological discovery of great importance, since in reptiles only precloacal and femoral pores are known. Based on our field observations, this new Liolaemus is related to rocky environments, which are used as refuge by this omnivorous species, and when handled, very aggressive males.

Liolaemus, es el segundo género más diverso dentro de Iguania, con más de 245 especies. Se describe una nueva especie de Liolaemus, perteneciente al subgénero Eulaemus, grupo o sección de Liolaemus montanus. Esta especie habita en un sector cordillerano muy restringido de la Provincia de Salta, Argentina, y en la provincia de Atacama, Chile; siempre por arriba de los 3 600msnm. Este nuevo taxón presenta características de lepidosis y patrón de coloración claramente diferente a los de las demás especies que integran el grupo de L. montanus, se destaca como carácter exclusivo entre todos los Liolaemus, la presencia de poros postcloacales. Este carácter es novedoso, no sólo en el género, sino también en todos los Reptilia, tornándose un descubrimiento morfológico de suma importancia, ya que sólo se conocen para algunos reptiles únicamente poros precloacales y femorales. Con base en las observaciones de campo realizadas, este nuevo Liolaemus es una lagartija relacionada a los ambientes rocosos, que utiliza para refugiarse, es una especie omnívora y los machos son muy agresivos al ser manipulados.

[New Liolaemus (Iguania: Liolaemidae) with a new morphological character from the border between Argentina and Chile]. / Nuevo Liolaemus (Iguania: Liolaemidae) con novedoso carácter morfológico, de la frontera entre Argentina y Chile.

Liolaemus belongs to the Eulaemus subgenus, that is included in the Liolaemus montanus group or section, and is distributed in Argentina, Bolivia, Chile and Peru. The species members of this clade inhabit arid and high altitude environments, usually above 2800 m, and have a strong tendency to herbivory and a viviparous reproductive type. In a herpetological expedition to the Salta Province highlands, Argentina, in April 2012, we collected individuals of this new species for their description. The specimens were collected with loop, slaughtered by anesthesia and deposited in the herpetological collection of Fundación Miguel Lillo in Tucuman (FML). To characterize this new taxon, we analyzed 144 external morphological characters, referring primarily to lepidosis, color pattern, and body proportions, comparing with data from 66 constituent species of the L. montanus group (45 taxa from collection specimens and 21 from literature). Description of the colors in life was made in the field and based on photographs taken during the capture. The species described in this work inhabits a very narrow mountain range area in Salta Province (Argentina), and the Atacama Region (Chile), always above the 3600 m. This new taxon shows characteristics of lepidosis and color patterns clearly different from the other species members of the L. montanus group: the maximum snout-vent length is 72.9 mm; shows 74-96 scales around midbody, 89-104 dorsal scales between the occiput and hind limbs, 92-109 ventrals, precloacal pores are evident in both, males and females, and supernumerary pores in males. Also, the presence of postcloacal pores stands out as unique among all Liolaemus. This is a new character, not only for the genus, but also to all Reptilia, becoming a morphological discovery of great importance, since in reptiles only precloacal and femoral pores are known. Based on our field observations, this new Liolaemus is related to rocky environments, which are used as refuge by this omnivorous species, and when handled, very aggressive males.

Running in cold weather: morphology, thermal biology, and performance in the southernmost lizard clade in the world (Liolaemus lineomaculatus section: Liolaemini: Iguania).

The integration or coadaptation of morphological, physiological, and behavioral traits is represented by whole-organism performance traits such as locomotion or bite force. Additionally, maximum sprint speed is a good indicator of whole-organism performance capacity as variation in sprinting ability can affect survival. We studied thermal biology, morphology, and locomotor performance in a clade of Liolaemus lizards that occurs in the Patagonian steppe and plateaus, a type of habitat characterized by its harsh cold climate. Liolaemus of the lineomaculatus section display a complex mixture of conservative and flexible traits. The phylogenetically informed analyses of these ten Liolaemus species show little coevolution of their thermal traits (only preferred and optimum temperatures were correlated). With regard to performance, maximum speed was positively correlated with optimum temperature. Body size and morphology influenced locomotor performance. Hindlimbs are key for maximal speed, but forelimb length was a better predictor for sustained speed (i.e. average speed over a total distance of 1.2 m). Finally, sustained speed differed among species with different diets, with herbivores running on average faster over a long distance than omnivores.