Phylogenetic relationships within a patagonian clade of reptiles (Liolaemidae:Phymaturus) based on DNA sequences and morphology

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.

High reproductive effort in a vulnerable lizard from high altitudes in Argentina: Reproductive biology and sexual dimorphism in Phymaturus extrilidus

Reproductive biology is fundamental to understanding the ecology and evolution of lizards which, in turn, is essential for the definition of the species´ conservation status. We studied life-history traits related to the reproduction of the Phymaturus extrilidus lizard, including the male and female reproductive cycles, litter size, mean annual reproductive output, reproductive effort, sexual maturity size and sexual dimorphism, body condition, and fat body cycles. We found sexual dimorphism in size and shape, supporting the hypotheses of sexual and fecundity selection. Females exhibited biennial reproductive cycles synchronous with the annual prenuptial male cycle, adjusted for the maturation of the vitellogenic follicles of females. Females of P. extrilidus have the highest mean annual reproductive output (MARO=1.14) recorded in Phymaturus, and this is accompanied by the highest reproductive effort (C=0.28, C energetic =0.31). Births occur from late summer to early autumn. The female reproductive cycle, strictly biennial, like all species of the P. palluma group, and the vitellogenesis in particular, appear to be limited by body condition and the amount of fat body stored. This study presents the fundamental reproductive traits of P. extrilidus that can provide valuable information to be used in the evaluation of the conservation status of this species.

Looking at the past to infer into the future: Thermal traits track environmental change in Liolaemidae

The diversity of habitats generated by the Andes uplift resulted a mosaic of heterogeneous environments in South America for species to evolve a variety of ecological and physiological specializations. Species in the lizard family Liolaemidae occupy a myriad of habitats in the Andes. Here, we analyze the tempo and mode of evolution in the thermal biology of liolaemids. We assessed whether there is evidence of local adaptation (lability) or conservatism (stasis) in thermal traits. We tested the hypothesis that abiotic factors (e.g., geography, climate) rather than intrinsic factors (egg-laying [oviparous] or live-bearing [viviparous], substrate affinity) explain variation in field active body temperature (T_b ), preferred temperature (T_p ), hours of restriction of activity, and potential hours of activity. Although most traits exhibited high phylogenetic signal, we found variation in thermal biology was shaped by geography, climate, and ecological diversity. Ancestral character reconstruction showed shifts in T_b tracked environmental change in the past ∼20,000 years. Thermal preference is 3°C higher than T_b , yet exhibited a lower rate of evolution than T_b and air temperature. Viviparous Liolaemus have lower T_b s than oviparous species, whereas T_p is high for both modes of reproduction, a key difference that results in a thermal buffer for viviparous species to cope with global warming. The rapid increase in environmental temperatures expected in the next 50-80 years in combination with anthropogenic loss of habitats are projected to cause extirpations and extinctions in oviparous species.