Lizard Assemblages Research Articles

Lizard assemblage from a sand dune habitat from southeastern Brazil: a niche overlap analysis.

Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba). We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic) using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards.

Modern tropical forests harbor an enormous diversity of squamates, but fossilization in such environments is uncommon and little is known about tropical lizard assemblages of the Mesozoic. We report the oldest lizard assemblage preserved in amber, providing insight into the poorly preserved but potentially diverse mid-Cretaceous paleotropics. Twelve specimens from the Albian-Cenomanian boundary of Myanmar (99 Ma) preserve fine details of soft tissue and osteology, and high-resolution x-ray computed tomography permits detailed comparisons to extant and extinct lizards. The extraordinary preservation allows several specimens to be confidently assigned to groups including stem Gekkota and stem Chamaleonidae. Other taxa are assignable to crown clades on the basis of similar traits. The detailed preservation of osteological and soft tissue characters in these specimens may facilitate their precise phylogenetic placement, making them useful calibration points for molecular divergence time estimates and potential keys for resolving conflicts in higher-order squamate relationships.

Early Holocene turnover, followed by stability, in a Caribbean lizard assemblage

Understanding how communities are impacted by environmental perturbations is integral for addressing the ongoing biodiversity crisis that impacts ecosystems worldwide. The fossil record serves as a window into ancient interactions and the responses of communities to past perturbations. Here, we re-examine paleontological data from Katouche Bay, Anguilla, a Holocene site in the Lesser Antilles. We reveal that the site was more diverse than previously indicated, with long-term, continuous records of three genera of extant lizards (Anolis, Ameiva, and Thecadactylus), and the early Holocene presence of Leiocephalus, a large ground-dwelling lizard that has since been completely extirpated from the Lesser Antilles. The disappearance of Leiocephalus from Katouche Bay resulted in high turnover, decreased evenness, and decreased species richness—a trend that continues to the present day. Our body size reconstructions for the most abundant genus, Anolis, are consistent with the presence of only one species, Anolis cf. gingivinus, at Katouche Bay throughout the Holocene, contrary to previously published studies. Additionally, we find no evidence of dwarfism in A. cf. gingivinus, which contrasts with a global study of contemporary insular lizards. Our data reveal that the impacts of diversity loss on lizard communities are long lasting and irreversible over millennia.

Diversity and seasonal dynamic of a lizard assemblage in a Neotropical semiarid habitat

ABSTRACTWe assessed the lizard assemblage from a priority conservation Caatinga area from northeastern Brazil, through a pluriannual ecological approach, to expand the understanding on biodiversity patterns of Neotropical semiarid habitats. The studied area presented one of the richest lizard faunas among Caatinga sites, being composed primarily by species typical from open landscapes. The local species composition was more similar to assemblages from adjacent Caatinga ecoregions than to those from other areas within the same ecoregion. The inventoried lizard assemblage consisted of a few common species and a majority of low abundance ones, and its overall richness and abundance did not differ between rainy and dry months. Our findings demonstrated that the composition of lizard assemblages did not match with the current proposed Caatinga ecoregions, and revealed that the studied assemblage followed a lognormal species-abundance distribution, showing no significant seasonal fluctuation in richness and abundance.

Niche overlap analysis of a lizard assemblage from the Atlantic Rainforest, evaluation of arsenic toxicity in cladocerans, and molecular biology of mycoplasmas

Niche overlap analysis of a lizard assemblage from the Atlantic Rainforest, evaluation of arsenic toxicity in cladocerans, and molecular biology of mycoplasmas

Juxtaposition and Disturbance: Disentangling the Determinants of Lizard Community Structure

AbstractDisturbance alters the structure and dynamics of communities. Here, we examined the effects of seasonal flooding on the lizard community structure by comparing two adjacent habitats, a seasonally flooded and a non‐flooded forest, in a Cerrado–Amazon ecotone area, the Cantão State Park, Tocantins state, Brazil. Despite the strong potential impact of seasonal flooding, the only significant environmental difference detected was more termite mounds in non‐flooded forests. Species richness was significantly higher in the non‐flooded forest. Colobosaura modesta, followed by Mabuya frenata and Anolis brasiliensis, were the only species that differed in number of captures between sites. Colobosaura modesta was exclusively found in the non‐flooded forest, while Anolis brasiliensis was the most captured in the flooded forest. Mabuya frenata is indicated as an indicator species in the flooded forest, and Colobosaura modesta in the non‐flooded forest. We found a significant association between lizard abundances and habitat characteristics, with flooding, canopy cover, and logs being the best predictors. A phylogenetic community structure analysis indicated a lack of structure in both lizard assemblages. Overall, we show that seasonal flooding can strongly impact species richness and species occurrence patterns, but not phylogenetic community structure. The Amazon–Cerrado transition is undergoing pronounced transformations due to deforestation and climate change. Despite being species‐poor compared with central areas in Amazon or Cerrado, this ecotone harbors species with important adaptations that could hold the key to persistence in human‐disturbed landscapes or during periods of climate change.

The first lizard fossil (Reptilia: Squamata) from the Mesozoic of South Korea

Upper Cretaceous deposits in Mongolia, Chinese Inner Mongolia, and, more recently, southern China, have yielded individually rich and taxonomically diverser lizard assemblages. Here we describe the remains of a new terrestrial lizard, Asprosaurus bibongriensis gen. et sp. nov., from the Upper Cretaceous of South Korea. It represents the first record of a Mesozoic lizard from the Korean Peninsula and, although incomplete, is exceptional in its very large size. Characters of the mandible support attribution to crown-group Anguimorpha, with the closest similarities being to monstersaurs, the group represented today by the venomous North American Beaded lizard and Gila monster, genus Heloderma. This group is well-represented in the Upper Cretaceous fossil record in of eastern Asia, and the remains of large monstersaurs have been recovered from several dinosaur egg localities, suggesting dietary preferences similar to those of the living genus. The new Korean lizard, recovered from the Boseong Bibong-ri Dinosaur Egg Site, fits the same pattern.

Co-occurrence patterns in independently evolved groups of Mediterranean insectivorous vertebrates (lizards and shrews)

Soricid mammals and lizards are small-sized, insectivorous vertebrates that are widespread and abundant in Mediterranean habitats. Because of their broad sympatry and their diet similarity, these taxa have been suspected to compete for food. Therefore, co-occurrence patterns between these taxa were studied at 72 sites in southern Italy by means of trapping methods. The assemblages were quite distinct depending on the site bioclimate: for the Lacertidae,Podarcis siculusdominated in the thermo-Mediterranean sites andP. muralisin the temperate sites, whereas, for the soricids,Suncus etruscusand two species ofCrocidurawere dominant in thermo-Mediterranean sites and threeSorexspecies in the temperate sites. The mean number of captured soricids was statistically higher in the temperate sites, and was positively related to the first component of a Principal Component Analysis summarizing three collinear study site variables (elevation, mean annual temperature, annual rainfall), the reverse being true for lizards. Co-occurrence analysis revealed that a non-segregated structure was present in the dataset, whereas a randomization algorithm showed that the assemblage of small mammals and lizards was non-randomly structured, with the frequency distribution of shrews being non-independent by site from that of lizards. However, when we divided the sites by their bioclimatic regime (thermo-Mediterranean versus temperate), the non-randomness of the community structure disappeared, thus demonstrating that interspecific competition was not the main force driving these assemblages of species. The number of shrews captured in each sampling site was however significantly negatively related to the number of lizards, this pattern being linked to the bioclimate of the various sampling sites. Overall, our data indicated that the assemblage of shrews and lizards was likely regulated essentially by local climate and not by synecological (interspecific competition) dynamics.

An assemblage of lizards from the Early Cretaceous of Japan

© Palaeontological Association July 2015. The Early Cretaceous deposits of the Tetori Group of western Japan have yielded a diverse wetland vertebrate fauna including both aquatic and terrestrial components. The latter include several lizards, three of which have been named and described in detail: Kaganaias hakusanensis, a long-bodied aquatic lizard; Kuwajimalla kagaensis, a herbivorous borioteiioid; and Sakurasaurus shokawensis, a relative of the Chinese Jehol genus Yabeinosaurus. Here we describe lizard material from the Shiramine locality representing five or six additional taxa, three of which are named herein: a small lizard represented by two associations, but of unresolved phylogenetic position; a slightly larger lizard with tricuspid teeth that is related to borioteiioids; and a bizarre lizard with bicuspid teeth represented by a single, but morphologically unique, jaw. The three additional lizard morphotypes are unnamed. One has bicuspid teeth but unspecialised jaws. The second has small unicuspid teeth in a dentary bearing a deep coronoid process and resembling the dentary of the enigmatic Late Cretaceous Mongolian Myrmecodaptria microphagosa. The third morphotype is represented by a single fragmentary specimen and has small teeth in a deep jaw. Together, the Kuwajima lizards form a phylogenetically and morphologically diverse assemblage.

Past, present and future distributions of a local assemblage of congeneric lizards in southern California

Understanding how species and species assemblages will respond to climate shifts is critical for predicting the impacts of modern warming on biodiversity. Addressing this question, we collected location data for four sympatric Sceloporus lizard species across a species-rich region of southern California, constructed habitat suitability models for each, and simulated temperature shifts to predict distributions at the last glacial maximum (LGM) and for a gradient of predicted end-of-century levels of warming. Current habitat modeled for Sceloporus magister comprises 243,204ha, was 357,100ha at the LGM, and may be reduced to 99,780ha at a +3°C future scenario; current habitat modeled for Sceloporus occidentalis comprises 150,870ha, was 222,590ha at the LGM, and could be reduced to 62,800ha at a +3°C; for current habitat modeled for Sceloporus vandenburgianus comprises 18,990ha, was 78,830ha at LGM, and may be 8210ha at +3°C; and habitat modeled for Sceloporus orcutti currently comprises 57,830ha, was 28,660ha at the LGM, and may be 35,970 at +3°C. Having undergone multiple climate shifts, regions recognized for high biodiversity may have intrinsic characteristics supporting that biodiversity. Our results indicate that the elevational heterogeneity of this landscape provided suitable habitat for these species throughout a past cold climate extreme and will likely continue to do so under predicted future warming. We identified climate refugia, areas providing suitable habitat under both current and shifted climates, obviating the challenge for species with low dispersal capabilities to track rapidly changing climate envelopes.

The importance of remnant native vegetation of Amazonian submontane forest for the conservation of lizards.

Forest fragmentation affects animal population dynamics mainly by loss of habitat and disruption of animal movement. Lizard assemblages are affected by environmental changes, but, depending on their ecological needs, some species might be more vulnerable than others. The southern Amazon suffers accelerated anthropic actions replacing natural environments by farmland (crops and pasture). This region is considerably drier than most of the northern Amazon, with stational semi-deciduous forests fragmented and isolated by pasture, and crops to a lesser extent. Here we report data on lizard assemblages using semi-deciduous forests, forest edge and the surrounding pasture in the southern Amazon in Mato Grosso, Brazil. Lizards were collected in 21 forest fragments (41 to 7,035 ha) surrounded by pasture; using pitfall traps placed on a degradation gradient - from pasture inwards forest fragment (up to 200 m). We collected 242 individuals (14 species, seven families) in 6,300 trap-days. The pattern of species occurrence was largely nested and this nesting was associated with three habitat guilds (generalist, edge-tolerant, and forest species). Although there was no obvious fragmentation effect on lizards diversity community-wise, Hoplocercus spinosus, Bachia dorbignyi, Micrablepharus maximiliani and Kentropyx calcarta were more vulnerable to such effects than all other ten species collected. We verified that assemblages inhabiting pasture and forest edge are a nested subset of assemblages from the forest core. The remnant native vegetation is not distributed homogeneously and lizards species can persist in different parts of the landscape, therefore we recommend the protection of forest remnants as an important conservation action for lizards of the southern Amazon.

Species composition, richness and nestedness of lizard assemblages from Restinga habitats along the brazilian coast.

Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia) and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the "Nestedness Temperature Calculator" to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species) whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island). Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P <0.00001; 5000 randomisations; randomisation temperature = 51.45° ± 7.18° SD), indicating that lizard assemblages in the coastal restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.

Direct and Short-Term Effects of Fire on Lizard Assemblages from a Neotropical Savanna Hotspot

Abstract As in other savanna biomes, burns are common in the Cerrado biodiversity hotspot, profoundly affecting its entire biota. We review the direct and indirect effects of fire on lizards and find that previous studies on herpetofauna report little or no direct postfire mortality, likely as a result of adaptive behaviors, and that studies on indirect effects of burns often assume the absence of direct effects on the herpetofauna. We investigate the immediate effects of prescribed fires upon lizard mortality in three South American Cerrado physiognomies. We also investigate the short-term (12 months) effects of fire on lizard captures in cerrado sensu stricto, the most widespread Cerrado physiognomy. We found no immediate postfire mortality with lizards using burrows and termite nests as prime shelters. Most lizard species displayed narrowed microhabitat use and reduced activity immediately after the fire. Twelve months after the burn, the capture rate of most species increased or remained the same as b...

Relative importance of habitat use, range expansion, and speciation in local species diversity of Anolis lizards in Cuba

Variations in species richness of local assemblages may be explained by local ecological processes or large‐scale evolutionary and biogeographical processes. In Anolis lizards, species with different ecomorphs can coexist by occupying different niches. In addition, several species with the same ecomorph (e.g., trunk‐ground) can coexist, and the number of trunk‐ground anole species varies among local species assemblages. In this study, we assessed the importance of ecological interactions, number of speciation events, and range expansion for local and regional species diversity of these lizards. We examined the species richness and thermal microhabitat partitioning (considered to be a measure of ecological interaction) of 12 trunk‐ground anole species in 11 local assemblages in Cuba. The results indicated that the phylogenetic structure of trunk‐ground anole lizard assemblages was random. However, there was an overdispersion of preferences for thermal microhabitat use, which indicates that differences in microhabitat use are likely to occur within assemblages. We suggest that the number of speciation events within regions and the number of sympatrically coexisting species increases species richness at the local level. Migration appeared to be limited, leading to the range expansion of only three species with different thermal requirements. The thermal niches of species were conserved within Anolis allogus clade, whereas species within the Anolis homolechis and Anolis sagrei clades tended to change their thermal niches. Our results suggest that the species composition and richness in local assemblages could be explained by evolutionary history (the number of speciation events and limits to range expansion) and ecological processes (habitat partitioning). Of the ecological factors, the number of thermal (microhabitat use) and structural niches (e.g., vegetation) could limit the potential number of coexisting species within a local assemblage.

Patterns of lizard species richness within National Parks and Biosphere Reserves across North America's deserts

Warm deserts world-wide provide habitats for rich lizard species assemblages; North American deserts are no exception, however the desert regions of the US and Mexico are experiencing increasing habitat changes from multiple anthropogenic sources. Our objective here was to document current lizard species richness patterns across the North American deserts within the existing network of conservation areas. We identified 110 lizard species occurring across one or more of the 19 sites we analyzed. Three species richness hot spots were identified; a northern Baja California faunal extension into southern California in the US, and in Mexico, two sites within the state of Coahuila, as well as high endemism in the Cape Region of Baja California Sur. Species richness was associated with sites where desert ecoregions overlap and with insular isolation. Our uncertainty regarding how species will respond to the multifaceted aspects of global change is such that large protected natural areas with complex topography may be the most effective strategy for protecting desert lizards along with overall biodiversity. The 19 sites we analyzed represent the cores of a more robust conservation network that will be needed for the protection of biodiversity across North American Deserts.

Effects of wildfire, rainfall and region on desert lizard assemblages: the importance of multi-scale processes

Vertebrate populations are influenced by environmental processes that operate at a range of spatial and temporal scales. Wildfire is a disturbance that can affect vertebrate populations across large spatial scales, although vertebrate responses are frequently influenced by processes operating at smaller spatial scales such as topography, interspecific interactions and regional history. Here, we investigate the effects of a broad-scale wildfire on lizard assemblages in a desert region. We predicted that a rainfall gradient within the region affected by the wildfire would influence lizard responses to the fire by encouraging post-fire succession to proceed more rapidly in high-rainfall areas, and would be enabled in turn by more rapid vegetation recovery. To test our prediction, we censused lizards, measured rainfall, undertook vegetation surveys and sampled invertebrate abundance across burnt and unburnt habitat ecotones within three regional areas situated along a gradient of long-term annual rainfall. Lizard diversity was not affected by fire or region and lizard abundance was influenced only by region. Lizard assemblage composition was also only influenced by region, but this did not relate to differences in rainfall or habitat as we had predicted. Regional differences in lizard assemblages related instead to food availability. The observed differences also likely reflected regional differences in the strength of biotic interactions with predators and changes in land use. Our study shows that assemblage responses to a disturbance were not uniform within a large desert region and instead were influenced by other environmental processes operating simultaneously at multiple temporal and spatial scales.

Lizards and amphisbaenians (Reptilia, Squamata) from the late Eocene of Sossís (Catalonia, Spain)

A new diverse late Eocene lizard and amphisbaenian assemblage from the classical mammal locality of Sossis (Catalonia, Spain) is described. It represents the first Paleogene lizard assemblage from Spain and the first late Eocene lizard locality from the Iberian Peninsula. The family-level composition of the assemblage replicates that of other contemporaneous European localities, with the presence of iguanians, geckos, lacertids, scincids, cordyliforms, amphisbaenians, anguines, and glyptosaurines. Many of these families still occur in Catalonia, but the presence of thermophilic taxa like iguanians and cordyliforms are indicative of warmer conditions during the Eocene. The closest faunal match is with the contemporaneous French localities of the Phosphorites du Quercy. Sossis and other newly recovered Paleogene Spanish squamate assemblages have the potential to contribute to an understanding of patterns of faunal interchange between different Paleogene bioprovinces, complementing existing data on mammals. © Palaeontological Association March 2013.

Vegetation Refuges of a Sand Lizard Assemblage in Temperate Coastal Sand Dunes

Natural refuges constitute a fundamental resource in the habitat of any given species. Consequently, the knowledge of those elements that are used as protection from predators is a priority for conservation. We studied the antipredatory mechanisms of an assemblage of sand dune lizards, determining whether refuge sites are random or whether particular types are chosen depending on their availability. We also compared the frequencies of the use of refuge sites with the use of perch sites by individuals at initial detection. Liolaemus multimaculatus used sites under rocks, either as refuges or as perches, and sites under sub-shrubs (Senecio bergii) and clump herbs (Spartina ciliata) as refuge only. Liolaemus gracilis used sites under creeping herbs (almost exclusively Panicum racemosum) and sub-shrubs (Senecio bergii) as refuge and perch sites more frequently than expected. Liolaemus wiegmannii only used sub-shrubs (mainly Melilotus indicus but also Achyrocline satureioides and Senecio bergii) both as refuge and perch sites. We show that lizards of Costa Bonita select certain types of native psammophytic grassland plants as refuge. Most of the plants used as refuge are also used as perch sites.

A new lizard skull from the Purbeck Limestone Group (Lower Cretaceous) of England

Abstract The Purbeck Limestone Group of England has yielded a rich assemblage of Late Jurassic to Early Cretaceous (Berriasian) vertebrate fossils, including one of the most diverse Early Cretaceous lizard assemblages on record. Here we describe the first articulated lizard skull from Purbeck. The specimen was rediscovered in the collections of the British Geological Survey, having been excavated at least a century ago. Although originally assigned to the Purbeck genus Paramacellodus, with which it shares maxillary and some dental characters, the new Purbeck skull differs from other Purbeck genera, including Paramacellodus, in frontal, pterygoid and maxillary morphology. It is here assigned to a new genus and species. Cladistic analysis groups it with Lacertoidea, unlike Paramacellodus, Becklesius and Parasaurillus which group with scincids and cordyliforms.

Diversity and habitat use by snakes and lizards in coastal environments of southernmost Brazil

This study examined species composition differences among snake and lizard assemblages from coastal dunes and restinga habitats in southernmost Brazil. Animals were collected between April 2009 and March 2010 using pitfall traps, artificial shelters, and time-constrained searches in grasslands areas susceptible to flooding. Species richness was higher in the restinga, but lower than the observed in other Brazilian biomes, possibly associated with more unstable microclimate conditions and low habitat complexity (vertical and horizontal distribution of the vegetation) in this habitat. This hypothesis is supported by the fact that the most abundant species of both snakes and lizards have fossorial habits. The assemblage of snakes is apparently mainly determined by abiotic characteristics of the habitat, while the assemblage of lizards, by vegetation cover.