The distributions of amphibians, birds and mammals have underpinned global and local conservation priorities, and have been fundamental to our understanding of the determinants of global biodiversity. In contrast, the global distributions of reptiles, representing a third of terrestrial vertebrate diversity, have been unavailable. This prevented the incorporation of reptiles into conservation planning and biased our understanding of the underlying processes governing global vertebrate biodiversity. Here, we present and analyse the global distribution of 10,064 reptile species (99% of extant terrestrial species). We show that richness patterns of the other three tetrapod classes are good spatial surrogates for species richness of all reptiles combined and of snakes, but characterize diversity patterns of lizards and turtles poorly. Hotspots of total and endemic lizard richness overlap very little with those of other taxa. Moreover, existing protected areas, sites of biodiversity significance and global conservation schemes represent birds and mammals better than reptiles. We show that additional conservation actions are needed to effectively protect reptiles, particularly lizards and turtles. Adding reptile knowledge to a global complementarity conservation priority scheme identifies many locations that consequently become important. Notably, investing resources in some of the world’s arid, grassland and savannah habitats might be necessary to represent all terrestrial vertebrates efficiently
BackgroundWith over 3,500 species encompassing a diverse range of morphologies and ecologies, snakes make up 36% of squamate diversity. Despite several attempts at estimating higher-level snake relationships and numerous assessments of generic- or species-level phylogenies, a large-scale species-level phylogeny solely focusing on snakes has not been completed. Here, we provide the largest-yet estimate of the snake tree of life using maximum likelihood on a supermatrix of 1745 taxa (1652 snake species + 7 outgroup taxa) and 9,523 base pairs from 10 loci (5 nuclear, 5 mitochondrial), including previously unsequenced genera (2) and species (61).ResultsIncreased taxon sampling resulted in a phylogeny with a new higher-level topology and corroborate many lower-level relationships, strengthened by high nodal support values (> 85%) down to the species level (73.69% of nodes). Although the majority of families and subfamilies were strongly supported as monophyletic with > 88% support values, some families and numerous genera were paraphyletic, primarily due to limited taxon and loci sampling leading to a sparse supermatrix and minimal sequence overlap between some closely-related taxa. With all rogue taxa and incertae sedis species eliminated, higher-level relationships and support values remained relatively unchanged, except in five problematic clades.ConclusionOur analyses resulted in new topologies at higher- and lower-levels; resolved several previous topological issues; established novel paraphyletic affiliations; designated a new subfamily, Ahaetuliinae, for the genera Ahaetulla, Chrysopelea, Dendrelaphis, and Dryophiops; and appointed Hemerophis (Coluber) zebrinus to a new genus, Mopanveldophis. Although we provide insight into some distinguished problematic nodes, at the deeper phylogenetic scale, resolution of these nodes may require sampling of more slowly-evolving nuclear genes.
A well-supported and well-resolved phylogeny based on a concatenated data set from one mitochondrial and two nuclear genes, six morphological characters, and nine color pattern characters for 44 of the 50 species of the Southeast Asian Rock Geckos (genus Cnemaspis Strauch, 1887) is consistent with the previous taxonomy of Cnemaspis based solely on morphology and color pattern. Cnemaspis is partitioned into four major clades that collectively contain six species groups. The monophyly of all clades and species groups is strongly supported and they are parapatrically distributed across well-established, biogeographical regions ranging from southern Vietnam westward through southern Indochina, southward through the Thai-Malay Peninsula, then eastward to Borneo. Eight new species (Cnemaspis omari sp. nov. from the Thai-Malaysian border; C. temiah sp. nov. from Cameron Highlands, Pahang, Malaysia; C. stongensis sp. nov. from Gunung Stong, Kelantan, Malaysia; C. hangus sp. nov. from Bukit Hangus, Pahang, Malaysia; C. sundagekko sp. nov. from Pulau Siantan, Indonesia; C. peninsularis sp. nov. from southern Peninsular Malaysia and Singapore, and C. mumpuniae sp. nov. and C. sundainsula sp. nov. from Pulau Natuna Besar, Indonesia) are described based on morphology and color pattern and all but C. sundagekko sp. nov. are included in the phylogenetic analyses. Cnemaspis kendallii is polyphyletic and a composite of six species. An updated taxonomy consistent with the phylogeny is proposed for all 50 species and is based on 25 morphological and 53 color pattern characters scored across 594 specimens. Cladogenetic events and biogeographical relationships within Cnemaspis were likely influenced by this group's low vagility and the cyclical patterns of geographical and environmental changes in Sundaland over the last 25 million years and especially within the last 2.5 million years. The phylogeny indicates that nocturnality, diurnality, substrate preferences, and the presence of ocelli in the shoulder regions have evolved independently multiple times.
Aim: Clutch size is a key life-history trait. In lizards, it ranges over two orders of magnitude. The global drivers of spatial and phylogenetic variation in clutch have been extensively studied in birds, but such tests in other organisms are lacking. To test the generality of latitudinal gradients in clutch size, and their putative drivers, we present the first global-scale analysis of clutch sizes across lizard taxa. Location: Global. Time period: Recent. Major taxa studied: Lizards (Reptilia, Squamata, Sauria). Methods: We analysed clutch-size data for over 3,900 lizard species, using phylogenetic generalized least-square regression to study the relationships between clutch sizes and environmental (temperature, precipitation, seasonality, primary productivity, insularity) and ecological factors (body mass, insularity, activity times, and microhabitat use). Results: Larger clutches are laid at higher latitudes and in more productive and seasonal environments. Insular taxa lay smaller clutches on average. Temperature B I OS K E TCH Shai Meiri is interested in the evolution of traits, and its relationship with geography.
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CommentAvailability of new Bayesian-delimited gecko names and the importance of character-based species descriptions Leaché & Fujita [1] present an empirical example of Bayesian species delimitation (BSD; [2]) to recognize three new species of African geckos from within the range of the widespread taxon Hemidactylus fasciatus, Gray 1842. As with any new method, BSD will undoubtedly generate questions and discussions about its practicality and assumptions. However, the use of this method of delimiting species does not obviate the need to adhere to the practice of describing or defining species on the basis of intrinsic characters.In order for any species name in zoology to be available, it must satisfy the applicable provisions of Articles 11 -20 of the International Code of Zoological Nomenclature (1999) (hereafter 'the Code'). Relevant to this issue, 'To be available, every new name published after 1930 . . . must be accompanied by a description or definition that states in words characters that are purported to differentiate the taxon (Article 13.1.1, p. 17)' where a character is 'any attribute of organisms used for recognizing, differentiating, or classifying taxa' (Glossary, p. 101). Leaché & Fujita [1] do not provide descriptions or definitions for their new taxa, only putative diagnoses (recommended but not required under the Code (Recommendation 13A)), and these are based not upon characters but upon degree of support under their species delimitation model (e.g. 'This species includes all populations that cluster with those from the Togo Hills included in this study with strong support in the Bayesian species delimitation model'). Although geographical location could be argued to be an organismal attribute, (i) Article 12.3 and, by implication, Article 13.1 [3] clarify that the mention of a locality does not in itself constitute a description, and (ii) Leaché & Fujita [1] have not actually used locality as a character, but as an indicator of the cluster to which populations belong. The new names they propose thus lack definitions or descriptions of organismal attributes (characters) as required by the Code and their diagnoses consist solely of extrinsic relational statements about populations. The new names proposed for members of the H. fasciatus group (Hemidactylus coalescens, Hemidactylus eniangii, Hemidactylus kyaboboensis) fail to conform to Article 13 and are nomina nuda, and thus unavailable under the Code.The diagnoses of their new species are similar to the definitions of clade names under phylogenetic taxonomy, but their species descriptions are also unavailable under the PhyloCode [4], which defers to 'provisions of the appropriate rank-based code (e.g. . . . ICZN)' for species availability.The unavailability of Leaché and Fujita's gecko names rests on more than a technicality. We emphasize this point to highlight the very purpose of the taxonomic protocols inherent in the Code's adherence to character-based species definitions. The application of Leaché & Fujita's approach would no doubt fac...
Aim Small geographic ranges make species especially prone to extinction from anthropogenic disturbances or natural stochastic events. We assemble and analyse a comprehensive dataset of all the world's lizard species and identify the species with the smallest ranges—those known only from their type localities. We compare them to wide‐ranging species to infer whether specific geographic regions or biological traits predispose species to have small ranges. Location Global. Methods We extensively surveyed museum collections, the primary literature and our own field records to identify all the species of lizards with a maximum linear geographic extent of <10 km. We compared their biogeography, key biological traits and threat status to those of all other lizards. Results One in seven lizards (927 of the 6,568 currently recognized species) are known only from their type localities. These include 213 species known only from a single specimen. Compared to more wide‐ranging taxa, they mostly inhabit relatively inaccessible regions at lower, mostly tropical, latitudes. Surprisingly, we found that burrowing lifestyle is a relatively unimportant driver of small range size. Geckos are especially prone to having tiny ranges, and skinks dominate lists of such species not seen for over 50 years, as well as of species known only from their holotype. Two‐thirds of these species have no IUCN assessments, and at least 20 are extinct. Main conclusions Fourteen per cent of lizard diversity is restricted to a single location, often in inaccessible regions. These species are elusive, usually poorly known and little studied. Many face severe extinction risk, but current knowledge is inadequate to properly assess this for all of them. We recommend that such species become the focus of taxonomic, ecological and survey efforts.
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