Lizards

Rapid activation of central serotonergic systems occurs in response to the social stress of aggression in dominant lizards. The most rapid expression of serotonergic activity occurs in nucleus accumbens, hippocampus and brainstem. To compare previously measured responses induced by social stressors with those provoked by physical stress, serotonergic activity was examined following restraint stress (handling) and forced physical exertion. After handling, some male Anolis carolinensis were placed on a race track and either run until there was no movement following 1 min of prodding, or half that time. Controls were killed without treatment. Lizards stressed by handling showed rapid (25 s) increases in serotonergic activity (5-HIAA/5-HT) in striatum, dorsal cortex, locus ceruleus, and nucleus accumbens. Other changes in serotonergic systems caused by stress occurred in raphe and hippocampus. Serotonergic changes induced by handling stress were reversed by exercise (to 50% maximal exertion time) in subiculum, striatum and nucleus accumbens. The serotonergic profile of lizards run until they would no longer respond to prodding (maximal exertion time) was significantly different from that for more acute exertion in hippocampus, subiculum, striatum, medial amygdala, locus ceruleus, area postrema, and raphe. Physical stress (handling) mimicked social stress by producing rapid serotonergic changes in hippocampus, subiculum, nucleus accumbens and locus ceruleus. In contrast, the medial amygdala, which has previously been demonstrated to respond serotonergically to social stress only after a temporal delay, did not show a rapid response to restraint stress.

The evolution of viviparity requires modifications to multiple integrated physiological features to support embryonic development during pregnancy. Embryonic growth during pregnancy is dependent upon the capacity of the uterine vascular system to satisfy increasing embryonic oxygen demand throughout gestation. We tested the hypothesis that total surface area of uterine blood vessels increases in concert with embryonic growth, and hence its oxygen demand, during gestation. We used immunofluorescence and laser-scanning confocal microscopy to quantify uterine microvascular density and morphology during gestation in the oviparous skink Ctenotus taeniolatus and in Saiphos equalis, a skink species with prolonged egg retention. For C. taeniolatus, vessel density (Nv) and vessel length-density (Lv) in the embryonic hemisphere of the uterus is 23% and 17% less, respectively, than that of S. equalis and vascular surface-area does not differ as a function of embryo stage. For S. equalis, overall Nv, Lv, and vessel diameter (Dv), does not change during the first half of gestation but increases by 36% (Nv), 44% (Lv), and 60% (Dv) by near-term embryo stages late in gestation. The chorioallantoic membrane of S. equalis increases in absolute size but vascular density does not differ as a function of embryo stage. The marked increase in uterine vascular density during late gestation coincides with the phase of rapid growth in embryo mass and concomitant increase in metabolic rate. Expansion of the uterine vascular bed in concert with embryo size and metabolism is likely to be an important transitional step in the evolution of viviparity. Anat Rec, 293:829–838, 2010. © 2010 Wiley-Liss, Inc.

Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR. Citation: Fitze PS, Cote J, San-Jose LM, Meylan S, Isaksson C, et al. (2009) Carotenoid-Based Colours Reflect the Stress Response in the Common Lizard. PLoS ONE 4(4): e5111.

This is a draft of the introductory chapter of a book-in-progress entitled Lizard, which has been contracted for publication in the Animal series of Reaktion Books in London. It discusses the changing definitions of "lizard" throughout history, and the  methodological difficulties, together with their philosophical foundation, involved in settling on a single definition today.  These are compared with the problems of settling on a single meaning for "humankind." It concludes that the meaning of "lizard" cannot be fixed, and the animal may only be understood within the context of an evolving tradition. I would be very interested in any comments or suggestions.

The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km 2 to 376 km 2 . Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin's niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma.

Uteri of Anolis carolinensis exhibited spontaneous rhythmic contractions in vitro. Addition of arginine vasotocin (AVT) caused an immediate, strong, tonic contraction followed by rhythmic contractions with the same frequency as spontaneous contractions but of a greater amplitude. At low tension (1.5 g) the AVT-induced tonic contraction was blocked by low dose of indomethacin, suggesting that it is influenced by calcium rather than prostaglandins (PGs). An increase in tension (from 1.5 to 15 g) reduced the duration of the AVT-induced tonic contraction; this stretch-induced decrease was also blocked by indomethacin. Stretch also decreased the duration of the rhythmic contractions, but this stretch effect was not inhibited by indomethacin. The rest interval between rhythmic contractions was decreased by PGF 2a and PGE 2 , and indomethacin or stretch blocked these PG effects. Indomethacin, AVT, or stretch alone did not affect PGF 2a secretion from AVT-treated uteri. Stretch also reduced PGF 2a secretion from AVT-treated uteri, an effect inhibited by indomethacin.

Female green iguanas, Iguana iguana, were caught in Belize, Central America (17"N), in December, at the onset of seasonal gonadal activity. The animals were immediately transferred to San Diego (32"N). Ovarian follicular development continued, with peak plasma hormone levels measured in January and February; 200 pg/ml for progesterone (P) and 800 pg/ml for

Background: Birds are one of the most highly successful and diverse groups of vertebrates, having evolved a number of distinct characteristics, including feathers and wings, a sturdy lightweight skeleton and unique respiratory and urinary/excretion systems. However, the genetic basis of these traits is poorly understood. Results: Using comparative genomics based on extensive searches of 60 avian genomes, we have found that birds lack approximately 274 protein coding genes that are present in the genomes of most vertebrate lineages and are for the most part organized in conserved syntenic clusters in non-avian sauropsids and in humans. These genes are located in regions associated with chromosomal rearrangements, and are largely present in crocodiles, suggesting that their loss occurred subsequent to the split of dinosaurs/birds from crocodilians. Many of these genes are associated with lethality in rodents, human genetic disorders, or biological functions targeting various tissues. Functional enrichment analysis combined with orthogroup analysis and paralog searches revealed enrichments that were shared by non-avian species, present only in birds, or shared between all species.

The exquisite transitional fossil Tetrapodophis e described as a stem-snake with four small legs from the Lower Cretaceous of Brazil e has been widely considered a burrowing animal, consistent with recent studies arguing that snakes had fossorial ancestors. We reevaluate the ecomorphology of this important taxon using a multivariate morphometric analysis and a reexamination of the limb anatomy. Our analysis shows that the body proportions are unusual and similar to both burrowing and surface-active squa-mates. We also show that it exhibits striking and compelling features of limb anatomy, including enlarged first metapodials and reduced tarsal/carpal ossification e that conversely are highly suggestive of aquatic habits, and are found in marine squamates. The morphology and inferred ecology of Tetra-podophis therefore does not clearly favour fossorial over aquatic origins of snakes.

Our storybooks are full of lizards, but we usually call them something else—dragons, serpents, dinosaurs or monsters. These stories vastly increase their size, bestow wings upon them, make them exhale flame, and endow them with magical powers. Lizards stimulate the human imagination unlike most other animals, despite generally being small, soundless, and hidden from sight in burrows, treetops, and crevices. They can blend into a vast range of environments, from rocky coasts to deserts to rain forests. Their fluid motion can make us think of water, while their curvilinear form suggests vegetation. Their stillness suggests death, while their sudden arousal is like resurrection. This delightful book gives lizards their due, demonstrating how the story of lizards is interwoven with the history of human imagination. Boria Sax considers the lizard as a sensual being—a symbol, a myth, a product of evolution and an aesthetic form. He describes the diversity of lizards and traces the representation of the reptile in cultures including those of pre-conquest Australia, the Quiché Maya, Mughal India, and central Africa. Illustrated throughout with beguiling images, Lizard is a unique and often surprising introduction to a popular but little-understood reptile.

Photoreceptors are the first in the chain of neurons that process visual information. In lateral eyes of vertebrates, light hyperpolarizes rod and cone photoreceptors that synapse onto bipolar and horizontal cells in the first synaptic layer of the retina. The sign of the photoreceptor signal is either conserved or inverted in bipolar cells, resulting in chromatically dependent depolarizing and hyperpolarizing responses to visual stimuli. Visual information is then conveyed to the second synaptic layer for encoding and transmission to the brain by ganglion cells. The parietal (third) eye of lizards does not contain bipolar cells or other interneurons. Photoreceptors synapse directly onto ganglion cells and yet, even in the absence of interneurons, antagonistic chromatic mechanisms modulate the ganglion cell responses. We report here that chromatic antagonism in the third eye originates in the chromatically dependent hyperpolarizing and depolarizing response of the photoreceptors to ...

Lactate dehydrogenase isoenzyme-1 was purified from fiver of Uromastix hardwickii using colchicine-Sepharose and heat-inactivation methods. The crude enzyme showed four isoenzymes by agarose gel electrophoresis (AGE). The purified enzyme showed a single band after native AGE and SDS-PAGE corresponding to a molecular weight of 34 kDa. The enzyme did not bind with DEAE-Sepharose at pH 7.2. The optimum pH for forward reaction was 7.5, while for reverse reaction, the maximum activity was at pH 9.5. The Km values for pyruvate, NADH, lactate and NAD + were 0.105, 0.045, 9.0 and 0.011 mM, respectively. The pyruvate showed maximum activity at about 150/~M and then starts showing inhibition at higher concentration. Pre-heating of enzyme showed that it was stable at 80°C for 30 min and at 100°C it became inactive immediately. Oxalate, glutamate, Cu z+, Co z+, Mn 2+, and Mg 2+ have shown inhibitory effects both for forward-and reverse-reactions. From these properties, we suggest that LDH-1 from Uromastix fiver may be quite different from that of other vertebrates.

Biological impacts of climate warming are predicted to increase with latitude, paralleling increases in warming. However, the magnitude of impacts depends not only on the degree of warming but also on the number of species at risk, their physiological sensitivity to warming and their options for behavioural and physiological compensation. Lizards are useful for evaluating risks of warming because their thermal biology is well studied. We conducted macrophysiological analyses of diurnal lizards from diverse latitudes plus focal species analyses of Puerto Rican Anolis and Sphaerodactyus. Although tropical lowland lizards live in environments that are warm all year, macrophysiological analyses indicate that some tropical lineages (thermoconformers that live in forests) are active at low body temperature and are intolerant of warm temperatures. Focal species analyses show that some tropical forest lizards were already experiencing stressful body temperatures in summer when studied several decades ago. Simulations suggest that warming will not only further depress their physiological performance in summer, but will also enable warm-adapted, open-habitat competitors and predators to invade forests. Forest lizards are key components of tropical ecosystems, but appear vulnerable to the cascading physiological and ecological effects of climate warming, even though rates of tropical warming may be relatively low.

Ontogenetic variation in venom composition was examined in the Pacific rattlesnakes Crotalus viridis helleri and C. v. oreganus. Venoms were analyzed for protease, phospholipase A2, L-amino acid oxidase, exonuclease and elastinolytic activities, and toxicity toward a native prey (Sceloporus graciosus). Protease activity increased significantly with size; L-amino acid oxidase and exonuclease activities also tended to increase. Phospholipase A2 activity decreased significantly with size, as did venom toxicity. These factors produce a highly toxic venom with low protease activity in juvenile snakes, which facilitates efficient handling of lizards and young rodents. Analysis of gut contents of museum specimens showed that lizards constitute a major fraction of prey taken by juvenile rattlesnakes. Lizards continue to be taken with high frequency until snakes reach approx. 500 mm in total length; above this size, mammals are taken exclusively. As snakes increase in size, they feed on larger mammalian prey, and a functionally different venom is produced. Venom from adult Pacific rattle-snakes is less toxic but has high protease activity, aiding in the digestion of prey in a thermally variable environment.

Lizards of the World is ultimate book on these fascinating creatures, featuring the all the different types of lizard worldwide. As survivors from the time of the dinosaurs, lizards are scaly, cold-blooded, living fossils – relics from a prehistoric world that remain alive and well in ours. Lizards exert a morbid fascination, in many mythologies they are dark creatures, symbolizing death and misfortune. From chameleons and skinks to geckos and iguanas, Lizards of the World brings these creatures firmly into the light, to reveal their extraordinary diversity Found in almost every type of terrain globally, there are almost 6,500 species of lizard, including lizards with frills, horns or wings, those that drop their tails, and others that squirt blood from their eyes. Here, the lizard family and subfamily profiles, organized phylogenetically, are illustrated with stunning photography. Each profile includes a population distribution map, a table of essential information and a fascinating commentary revealing notable characteristics, fresh scientific understanding and the diversity of species. Written by world-renowned herpetologist Mark O’Shea, Lizards of the World is a magnificent showcase of the natural history and beauty of these remarkable reptiles.

A história de vida é o resultado de um desafio ecológico imposto pelo ambiente, tenta explicar como a evolução molda os organismos a fim de atingir o sucesso reprodutivo (Stearns, 2000). Sendo assim está intimamente relacionada com as mudanças climáticas em pauta nesta edição especial. Neste artigo são revistos os efeitos de mudanças de temperatura e precipitação em alguns traços fenotípicos de história de vida de lagartos. Ao final, com base no conhecimento atual sobre os lagartos brasileiros e nas previsões de mudanças climáticas para o Brasil, são feitas algumas previsões de mudanças na história de vida dos lagartos. Palavras-chave. Mudanças climáticas, lagartos, história de vida.

In 1969, a palaeontologist proposed 1 that theropod dinosaurs used their tails as dynamic stabilizers during rapid or irregular movements, contributing to their depiction as active and agile predators. Since then the inertia of swinging appendages has been implicated in stabilizing human walking 2,3 , aiding acrobatic manoeuvres by primates 4-8 and rodents 9 , and enabling cats to balance on branches . Recent studies on geckos suggest that active tail stabilization occurs during climbing, righting and gliding. By contrast, studies on the effect of lizard tail loss show evidence of a decrease, an increase or no change in performance . Application of a control-theoretic framework could advance our general understanding of inertial appendage use in locomotion. Here we report that lizards control the swing of their tails in a measured manner to redirect angular momentum from their bodies to their tails, stabilizing body attitude in the sagittal plane. We video-recorded Red-Headed Agama lizards (Agama agama) leaping towards a vertical surface by first vaulting onto an obstacle with variable traction to induce a range of perturbations in body angular momentum. To examine a known controlled tail response, we built a lizard-sized robot with an active tail that used sensory feedback to stabilize pitch as it drove off a ramp. Our dynamics model revealed that a body swinging its tail experienced less rotation than a body with a rigid tail, a passively compliant tail or no tail. To compare a range of tails, we calculated tail effectiveness as the amount of tailless body rotation a tail could stabilize. A model Velociraptor mongoliensis supported the initial tail stabilization hypothesis 1 , showing as it did a greater tail effectiveness than the Agama lizards. Leaping lizards show that inertial control of body attitude can advance our understanding of appendage evolution and provide biological inspiration for the next generation of manoeuvrable search-and-rescue robots.

Reproductively, South American Mabuya are among the most extraordinary of squamate reptiles.  Not only have these scincid lizards evolved a degree of placentotrophy that exceeds that of all other known squamates, but they have converged strongly on a pattern usually assumed to be confined to eutherian mammals.  Characteristics of this reproductive pattern include viviparity, a lengthy gestation period, ovulation of small ova, formation of chorioallantoic placentae with chorionic areolae and a placentome, and placental provision of virtually all of the nutrients for development.  The independent evolution of such features among mammals and lizards represents one of the most striking cases of evolutionary convergence in reproductive specializations to be documented among terrestrial vertebrates (Blackburn, 1991).



Aside from their similarities to eutherians, however, South American lizards of the genus Mabuya  are highly worthy of study in their own right.  These lizards represent an extreme in the spectrum of reptilian reproductive features, and their specializations appear to be of functional significance in the environments that they inhabit (Vitt and Blackburn, 1983, 1991; Vitt, in press).  The extent of intra-generic diversity in reproductive mode, placentation, and fetal nutritional mode suggests Mabuya to be a model taxon for inquiries into the evolution of viviparity and placentotrophy, as well as the evolution of structural – functional complexes, such as is represented by the placenta.



Unfortunately, survival of at least some of the South American species of Mabuya  is now threatened over wide portions of their ranges.  For example, during the past ten years of habitat destruction in Pernambuco, M. heathi has become increasingly scarce, and the range of M. bistriata undoubtedly is being diminished by devastation of the Amazonian rainforest.  Extinction of these remarkable species would be an incalculable loss, and protection and maintenance of the genus Mabuya throughout South America is of the utmost urgency.

Snakes and lizards are considered 'stoic' animals and often show only non-specific signs of illness. Consequently, diagnostic imaging -along with clinical examination and laboratory tests -is gaining importance in making a final diagnosis and establishing a correct therapy. The large number of captive snake and lizard species commonly kept as pets, together with the high inter-and intraspecific morphological variability that is innate in these animals, make the analysis of diagnostic images challenging for the veterinary practitioner. Moreover, a thorough knowledge of the anatomy, physiology and pathology of the species that are the object of clinical investigation is mandatory for the correct interpretation of diagnostic images. Despite the large amount of clinical and scientific work carried out in the past two decades, the radiographic features of snakes and lizards have not undergone systematic description, and therefore veterinarians often have to rely mostly on anatomical studies rather than radiological literature. The aim of this paper is to review the most commonly used diagnostic imaging modalities, as well as to provide an overview of the available international original studies and scientific reviews describing the normal and pathological imaging features in snakes and lizards. At the present time, some excellent references describing the anatomy, physiology (O'Malley 2005) and pathology (Mader 2005a, Jacobson 2007) of reptile species belonging to the clade Squamata are available, thus enabling a great increase in the demand for veterinary speciality health services for captive snakes and lizards. A particularly good reference is the Biology of the Reptilia series, produced by the Society for the Study of Amphibians and Reptiles from 1970 to 2010.

Recently, there has been significant interest in developing dry adhesives mimicking the gecko adhesive system, which offers several advantages compared to conventional pressure-sensitive adhesives. Specifically, gecko adhesive pads have anisotropic adhesion properties; the adhesive pads (spatulae) stick strongly when sheared in one direction but are non-adherent when sheared in the opposite direction. This anisotropy property is attributed to the complex topography of the array of fine tilted and curved columnar structures (setae) that bear the spatulae. In this study, we present an easy, scalable method, relying on conventional and unconventional techniques, to incorporate tilt in the fabrication of synthetic polymer-based dry adhesives mimicking the gecko adhesive system, which provides anisotropic adhesion properties. We measured the anisotropic adhesion and friction properties of samples with various tilt angles to test the validity of a nanoscale tape-peeling model of spatular function. Consistent with the peel zone model, samples with lower tilt angles yielded larger adhesion forces. The tribological properties of the synthetic arrays were highly anisotropic, reminiscent of the frictional adhesion behavior of gecko setal arrays. When a 60°tilt sample was actuated in the gripping direction, a static adhesion strength of ∼1.4 N/cm 2 and a static friction strength of ∼5.4 N/cm 2 were obtained. In contrast, when the dry adhesive was actuated in the releasing direction, we measured an initial repulsive normal force and negligible friction.

The blue-tongue lizard (Tiliqua scincoides) is a variety of large skink common throughout Australia. There are seven species of Tiliqua and all of them have long bodies, short limbs and short and robust tails. T. scincoides occurs in a wide range of habitats; its diet is omnivorous. When threatened, it opens the mouth and protrudes its characteristic large fleshy cobalt blue tongue. It is currently found as a popular species and also as a pet animal in the European countries. No data are available in literature about the morphology of the tongue of T. scincoides; therefore, the aim of the present study was to investigate by means of scanning electron microscopy and light microscopy, the anatomy of the dorsal lingual surface. Our results demonstrate the presence of a tongue tip with a smooth surface without papillae. The foretongue was characterized by a stratified epithelium with foliate-like papillae and deep interpapillar spaces in the middle part and cylindrical papillae with a flat surface in the lateral parts. All the posterior area of the tongue was characterized by more compacted papillae and the inter-papillar spaces were very narrow. Light microscopy showed the presence of melanin throughout the tongue. No taste buds were recognized on the lingual dorsal surface. Therefore, the papillae probably have a mechanical function showing an important role in the swallowing phase. The morphology of the tongue surface can be correlated to the diet and, different roles, as in other examined species, can be hypothesized for different areas.

Se presenta una actualización de la lista de las taxa confirmadas o probables, del Orden Sauria (lagartijas) de Bolivia, con discusiones sobre aspectos sistemáticos, taxonómicos y biogeográficos. Hasta septiembre de 2005, se reconoce 97 especies confirmadas de saurios para Bolivia, con otras 37 especies probables. De los saurios confirmados, 13 especies y una subespecie son endémicas para Bolivia. Se presenta además una serie de regiones prioritarias para inventarios de la saurofauna boliviana.

Extreme weather events, such as unusually hot or dry conditions, can cause death by exceeding physiological limits, and so cause loss of population. Survival will depend on whether or not susceptible organisms can find refuges that buffer extreme conditions. Microhabitats offer different microclimates to those found within the wider ecosystem, but do these microhabitats effectively buffer extreme climate events relative to the physiological requirements of the animals that frequent them? We collected temperature data from four common microhabitats (soil, tree holes, epiphytes, and vegetation) located from the ground to canopy in primary rainforests in the Philippines. Ambient temperatures were monitored from outside of each microhabitat and from the upper forest canopy, which represent our macrohabitat controls. We measured the critical thermal maxima (CT max ) of frog and lizard species, which are thermally sensitive and inhabit our microhabitats. Microhabitats reduced mean temperature by 1-2°C and reduced the duration of extreme temperature exposure by 14-31 times. Microhabitat temperatures were below the CT max of inhabitant frogs and lizards, whereas macrohabitats consistently contained lethal temperatures. Microhabitat temperatures increased by 0.11-0.66°C for every 1°C increase in macrohabitat temperature, and this nonuniformity in temperature change influenced our forecasts of vulnerability for animal communities under climate change. Assuming uniform increases of 6°C, microhabitats decreased the vulnerability of communities by up to 32-fold, whereas under nonuniform increases of 0.66 to 3.96°C, microhabitats decreased the vulnerability of communities by up to 108-fold. Microhabitats have extraordinary potential to buffer climate and likely reduce mortality during extreme climate events. These results suggest that predicted changes in distribution due to mortality and habitat shifts that are derived from macroclimatic samples and that assume uniform changes in microclimates relative to macroclimates may be overly pessimistic. Nevertheless, even nonuniform temperature increases within buffered microhabitats would still threaten frogs and lizards.

Thermoregulatory studies of ectothermic organisms are an important tool for ecological physiology, evolutionary ecology and behavior, and recently have become central for evaluating and predicting global climate change impacts. Here, we present a novel combination of field, laboratory, and modeling approaches to examine body temperature regulation, habitat thermal quality, and hours of thermal restriction on the activity of two sympatric, aridlands horned lizards (Phrynosoma cornutum and Phrynosoma modestum) at three contrasting Chihuahuan Desert sites in Mexico. Using these physiological data, we estimate local extinction risk under predicted climate change within their current geographical distribution. We followed the Hertz et al. (1993, Am. Nat., 142, 796-818) protocol for evaluating thermoregulation and the Sinervo et al. (2010, Science, 328, 894-899) eco-physiological model of extinction under climatic warming. Thermoregulatory indices suggest that both species thermoregulate effectively despite living in habitats of low thermal quality, although high environmental temperatures restrict the activity period of both species. Based on our measurements, if air temperature rises as predicted by climate models, the extinction model projects that P. cornutum will become locally extinct at 6% of sites by 2050 and 18% by 2080 and P. modestum will become extinct at 32% of sites by 2050 and 60% by 2080. The method we apply, using widely available or readily acquired thermal data, along with the modeling, appeared to identify several unique ecological traits that seemingly exacerbate climate sensitivity of P. modestum.

The central bearded dragon (Pogona vitticeps) is one of the most popular pet lizards. However, little is known regarding their nutrient requirement, or their natural diet. Therefore, the stomach contents of 14 free-roaming P. vitticeps were determined by flushing. These stomach contents were described taxonomically, and analyzed for crude protein content as well as fatty acid content and composition. Most of the dry matter intake was in the form of animal material (61%) stemming from nine arthropod orders. The most abundant were alates of the termite Drepanotermes sp., accounting for 95% of the total number of prey items and more than half of the total dry matter (DM) intake. Plant material contributed 16% of the total DM intake. The diets were high in crude protein (41-50% DM) and the total fatty acid content was 14-27% of the DM intake. The main fatty acid was C18:1n9c (51-56% of total fatty acids), and polyunsaturated fatty acids (n3 and n6) comprised 6-8% of the total fat intake. Our data suggest that P. vitticeps is an opportunistic predator, which exploits the seasonal availability of prey. Based on our data and other studies, a diet consisting of several insect species, supplemented with leafy vegetables, rich in n3 FA's, would best resemble the expected natural diet of P. vitticeps. Zoo Biol. XX:XX-XX, 2015.

The behaviour and body temperatures of the bearded dragon (Pogona vitticeps) were recorded during periods with handling and non-handling intervals. Differences in perching and hiding were observed after the animals were handled but basking and locomotory activity remained almost constant. The observed differences in behaviour appeared to have no influence on either set point or variance in body temperatures.

The behaviour, body temperatures and respiratory rates of captive bearded dragons (Pogona vitticeps) were recorded during periods with handling and non-handling intervals. Respiratory rates increased at approximately equal rates with increasing body temperatures irrespective of whether the animals were handled or not. Respiratory rates increased significantly after handling but there were no significant differences in behaviour before and after handling. The implications have been discussed in respect to animal usage in captive husbandry and education programmes.

Inference of colour patterning in extinct dinosaurs 1-3 has been based on the relationship between the morphology of melanin-containing organelles (melanosomes) and colour in extant bird feathers. When this relationship evolved relative to the origin of feathers and other novel integumentary structures, such as hair and filamentous body covering in extinct archosaurs, has not been evaluated. Here we sample melanosomes from the integument of 181 extant amniote taxa and 13 lizard, turtle, dinosaur and pterosaur fossils from the Upper-Jurassic and Lower-Cretaceous of China. We find that in the lineage leading to birds, the observed increase in the diversity of melanosome morphologies appears abruptly, near the origin of pinnate feathers in maniraptoran dinosaurs. Similarly, mammals show an increased diversity of melanosome form compared to all ectothermic amniotes. In these two clades, mammals and maniraptoran dinosaurs including birds, melanosome form and colour are linked and colour reconstruction may be possible. By contrast, melanosomes in lizard, turtle and crocodilian skin, as well as the archosaurian filamentous body coverings (dinosaur 'protofeathers' and pterosaur 'pycnofibres'), show a limited diversity of form that is uncorrelated with colour in extant taxa. These patterns may be explained by convergent changes in the key melanocortin system of mammals and birds, which is known to affect pleiotropically both melanin-based colouration and energetic processes such as metabolic rate in vertebrates 4 , and may therefore support a significant physiological shift in maniraptoran dinosaurs.

Autino, A. G. y Montero, R. 2012. Guía de Vertebrados de Bajo La Alumbrera, Catamarca, Argentina. Minera Alumbrera Limited, 224 pp.  Edición rústica: ISBN 978-987-28792-0-4; Edición cartoné: ISBN 978-987-28792-1-1.

Contiene información sobre las 93 especies más conspicuas de los Vertebrados de la región de Bajo De La Alumbrera (Catamarca, Argentina), incluyendo fotografías, dibujos, su descripción, distribución, biología y estado de conservación.