Adaptation to life in aeolian sand: how the sandfish lizard, Scincus scincus, prevents sand particles from entering its lungs.

The sandfish lizard, Scincus scincus (Squamata: Scincidae), spends nearly its whole life in aeolian sand and only comes to the surface for foraging, defecating and mating. It is not yet understood how the animal can respire without sand particles entering its respiratory organs when buried under thick layers of sand. In this work, we integrated biological studies, computational calculations and physical experiments to understand this phenomenon. We present a 3D model of the upper respiratory system based on a detailed histological analysis. A 3D-printed version of this model was used in combination with characteristic ventilation patterns for computational calculations and fluid mechanics experiments. By calculating the velocity field, we identified a sharp decrease in velocity in the anterior part of the nasal cavity where mucus and cilia are present. The experiments with the 3D-printed model validate the calculations: particles, if present, were found only in the same area as suggested by the calculations. We postulate that the sandfish has an aerodynamic filtering system; more specifically, that the characteristic morphology of the respiratory channel coupled with specific ventilation patterns prevent particles from entering the lungs.

Three new endemic species of Epictia Gray, 1845 (Serpentes: Leptotyphlopidae) from the dry forest of northwestern Peru.

Three new blind snake species of the genus Epictia are described based on material collected in the Peruvian Regions Amazonas, Cajamarca and La Libertad. All three species are well differentiated from all congeners based on characteristics of their morphology and coloration. They share 10 scale rows around the middle of the tail and possess two supralabials with the anterior one in broad contact with the supraocular. Epictia septemlineata sp. nov. has 16 subcaudal scales, 257 mid-dorsal scale rows, a yellowish-white rostral, and a black terminal spine. Epictia vanwallachi sp. nov. exhibits 16 subcaudals, 188 mid-dorsal scale rows, a grayish-brown rostral, and a yellow terminal spine. Epictia antoniogarciai sp. nov. features 14-18 subcaudals, 195-208 mid-dorsal scale rows, a bright yellow or yellowish-white rostral, and the terminal spine and terminal portion of the tail yellow. All three species were collected in the interandean dry forest valleys of the Marañón River and its tributaries. This region is an area of endemism and warrants further attention from systematic and conservation biologists.

A hybrid phylogenetic-phylogenomic approach for species tree estimation in African Agama lizards with applications to biogeography, character evolution, and diversification.

Africa is renowned for its biodiversity and endemicity, yet little is known about the factors shaping them across the continent. African Agama lizards (45 species) have a pan-continental distribution, making them an ideal model for investigating biogeography. Many species have evolved conspicuous sexually dimorphic traits, including extravagant breeding coloration in adult males, large adult male body sizes, and variability in social systems among colorful versus drab species. We present a comprehensive time-calibrated species tree for Agama, and their close relatives, using a hybrid phylogenetic-phylogenomic approach that combines traditional Sanger sequence data from five loci for 57 species (146 samples) with anchored phylogenomic data from 215 nuclear genes for 23 species. The Sanger data are analyzed using coalescent-based species tree inference using (*)BEAST, and the resulting posterior distribution of species trees is attenuated using the phylogenomic tree as a backbone constraint. The result is a time-calibrated species tree for Agama that includes 95% of all species, multiple samples for most species, strong support for the major clades, and strong support for most of the initial divergence events. Diversification within Agama began approximately 23 million years ago (Ma), and separate radiations in Southern, East, West, and Northern Africa have been diversifying for >10Myr. A suite of traits (morphological, coloration, and sociality) are tightly correlated and show a strong signal of high morphological disparity within clades, whereby the subsequent evolution of convergent phenotypes has accompanied diversification into new biogeographic areas.

Jack-of-all-trades master of all? Snake vertebrae have a generalist inner organization.

Snakes are a very speciose group of squamates that adapted to various habitats and ecological niches. Their ecological diversity is of particular interest and functional demands associated with their various styles of locomotion are expected to result in anatomical specializations. In order to explore the potential adaptation of snakes to their environment we here analyze variation in vertebral structure at the microanatomical level in species with different locomotor adaptations. Vertebrae, being a major element of the snake body, are expected to display adaptations to the physical constraints associated with the different locomotor modes and environments. Our results revealed a rather homogenous vertebral microanatomy in contrast to what has been observed for other squamates and amniotes more generally. We here suggest that the near-absence of microanatomical specializations in snake vertebrae might be correlated to their rather homogeneous overall morphology and reduced range of morphological diversity, as compared to lizards. Thus, snakes appear to retain a generalist inner morphology that allows them to move efficiently in different environments. Only a few ecologically highly specialized taxa appear to display some microanatomical specializations that remain to be studied in greater detail.

Two new endemic species of Ameiva (Squamata: Teiidae) from the dry forest of northwestern Peru and additional information on Ameiva concolor Ruthven, 1924.

We describe two new species of Ameiva Meyer, 1795 from the dry forest of the Northern Peruvian Andes. The new species Ameiva nodam sp. nov. and Ameiva aggerecusans sp. nov. share a divided frontal plate and are differentiated from each other and from their congeners based on genetic (12S and 16S rRNA genes) and morphological characteristics. A. nodam sp. nov. has dilated postbrachials, a maximum known snout-vent length of 101 mm, 10 longitudinal rows of ventral plates, 86-113 midbody granules, 25-35 lamellae under the fourth toe, and a color pattern with 5 longitudinal yellow stripes on the dorsum. Ameiva aggerecusans sp. nov. has not or only hardly dilated postbrachials, a maximum known snout-vent length of 99.3 mm, 10-12 longitudinal rows of ventral plates, 73-92 midbody granules, 31-39 lamellae under the fourth toe, and the females and juveniles of the species normally exhibit a cream-colored vertebral stripe on a dark dorsum ground color. We provide information on the intraspecific variation and distribution of A. concolor. Furthermore, we provide information on the environmental niches of the taxa and test for niche conservatism. 

A new species of the genus Calotes Cuvier, 1817 (Squamata: Agamidae) from southern Vietnam.

We describe a new species of the agamid genus Calotes Cuvier, 1817 from southern Vietnam, which is most similar to Calotes mystaceus Duméril & Bibron, 1837, but can be distinguished from the latter and its other congeners by genetic and morphological differences. We discuss the current distribution of the new species and its sister species C. mystaceus in Mainland Southeast Asia.

A new species of Kukri Snake (Oligodon Fitzinger, 1826; Squamata: Colubridae) from the Cat Tien National Park, southern Vietnam.

We describe a new species of the genus Oligodon from the lowland forests of Cat Tien National Park, Dong Nai Province, in southern Vietnam. Oligodon cattienensis sp. nov. is distinguished from the remaining Southeast Asian kukri snakes by the combination of the following characters: medium-sized, deeply forked hemipenes without spines, 17-17-15 dorsal scale rows, nasal entire, 2 small postoculars, almost equal in size, 167-178 ventrals, 31-35 subcaudals, 24-35 + 5 large dark-edged vertebral blotches in combination with a yellow-orange or red vertebral stripe between blotches, head pattern including ocular band, temporal bands and elongated chevron, ventrals pink or whitish (reddish in juveniles) in life, some bearing a quadrangular dark blotch on each lateral side, or ventrals being entirely dark. Based on the hemipenial morphology the new species is assigned to the Oligodon cyclurus species group. A comparison table for all Indochinese Oligodon is provided.

Eastward from Africa: palaeocurrent-mediated chameleon dispersal to the Seychelles islands.

Madagascar and the Seychelles are Gondwanan remnants currently isolated in the Indian Ocean. In the Late Cretaceous, these islands were joined with India to form the Indigascar landmass, which itself then split into its three component parts around the start of the Tertiary. This history is reflected in the biota of the Seychelles, which appears to contain examples of both vicariance- and dispersal-mediated divergence from Malagasy or Indian sister taxa. One lineage for which this has been assumed but never thoroughly tested is the Seychellean tiger chameleon, a species assigned to the otherwise Madagascar-endemic genus Calumma. We present a multi-locus phylogenetic study of chameleons, and find that the Seychellean species is actually the sister taxon of a southern African clade and requires accomodation in its own genus as Archaius tigris. Divergence dating and biogeographic analyses indicate an origin by transoceanic dispersal from Africa to the Seychelles in the Eocene-Oligocene, providing, to our knowledge, the first such well-documented example and supporting novel palaeocurrent reconstructions.

The anatomy of the respiratory system in Platysternon megacephalum Gray, 1831 (Testudines: Cryptodira) and related species, and its phylogenetic implications.

We discuss the morphology of the respiratory system regarding the phylogenetic relation among selected Testudines (Tetrapoda: Amniota). Lung structure and the associated coelomic organization are compared in Platysternon megacephalum and in representatives of the most-likely closely related taxa Chelydridae and Testudinoidea (Emydidae+Testudinidae). P. megacephalum shows horizontal intrapulmonary septation in the medial chambers, dividing them into dorsal and ventral lobes. This structure is found only in Platysternon and in the Emydidae, and is interpreted as a possible synapomorphy for these two taxa. In addition to further suggested synapomorphies for Platysternon and the Testudinoidea, we found - in contrast to previous reports - a small post-pulmonary septum (PPS) and incomplete coelomic compartmentalization in the Chelydridae. Thus, all major taxa of Testudines possess a PPS. Since this structure is also present in mammals, archosaurs and some lepidosaurs, the plesiomorphy of a coelomic compartmentalization by the PPS in amniotes in general should be considered. These preliminary results indicate that further comparative study of the respiratory apparatus might help resolve the phylogenetic relationships among the Testudines, as well as to shed light on its evolution among the Amniota.

Variation in body size and sexual size dimorphism in the most widely ranging lizard: testing the effects of reproductive mode and climate.

Reproductive mode, ancestry, and climate are hypothesized to determine body size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species' range, we analyzed how sex-specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south-western France) exhibited a smaller female size and less female-biased SSD than those of the western viviparous (France to Eastern Europe) and the eastern viviparous (Eastern Europe to Far East) lineages; this pattern persisted even after controlling for climatic effects. The phenotypic response to seasonality was complex: across the lineages, as well as within the eastern viviparous lineage, female size and SSD increase with increasing seasonality, whereas the western viviparous lineage followed the opposing trends. Altogether, viviparous populations seem to follow a saw-tooth geographic cline, which might reflect the nonmonotonic relationship of body size at maturity in females with the length of activity season. This relationship is predicted to arise in perennial ectotherms as a response to environmental constraints caused by seasonality of growth and reproduction. The SSD allometry followed the converse of Rensch's rule, a rare pattern for amniotes. Our results provide the first evidence of opposing body size-climate relationships in intraspecific units.

A new species of Dibamus Duméril Bibron, 1839 (Squamata: Dibamidae) from Pulau Manado Tua, Northern Sulawesi, Indonesia.

Based on three adult specimens, viz. two males and a female that form the type series, a new species of blind or worm-like lizards is described from Pulau (= Island) Manado Tua, a little volcanic island located off the northern tip of the Minahassa Peninsula of Sulawesi, Indonesia. Dibamus manadotuaensis sp. nov. differs from all congeneric species in the following unique combination of characters: maximum snout-vent length 135 mm; tail length up to 14.2 mm (i.e., 12-13% of SVL); labial and nasal sutures present and complete; four (three) postoculars; four to six scales on posterior edge of infralabial; 26-28 midbody scale rows; 30-33 transverse scale rows posterior to head; 25 transverse scale rows anterior to vent; 218-232 ventral scales; 39 subcaudal scales; relative size of frontal to frontonasal 0.68-0.73; relative size of interparietal to surrounding scales 0.67-1.43; 132-135 presacral and 21-24 postsacral vertebrae. Morphologically, D. manadotuaensis is most similar to D. celebensis, which occurs on mainland Sulawesi.Dibamus manadotuaensis sp. nov. represents the twenty-fourth species of Dibamus and the third species of this genus recorded from the Sulawesi region. At the same time, it is the only squamate species considered endemic for the islands of the Bunaken Marine National Park, to which Manado Tua belongs.

A global catalog of primary reptile type specimens.

We present information on primary type specimens for 13,282 species and subspecies of reptiles compiled in the Reptile Database, that is, holotypes, neotypes, lectotypes, and syntypes. These represent 99.4% of all 13,361 currently recognized taxa (11,050 species and 2311 subspecies). Type specimens of 653 taxa (4.9%) are either lost or not located, were never designated, or we did not find any information about them. 51 species are based on iconotypes. To map all types to physical collections we have consolidated all synonymous and ambiguous collection acronyms into an unambiguous list of 364 collections holding these primary types. The 10 largest collections possess more than 50% of all (primary) reptile types, the 36 largest collections possess more than 10,000 types and the largest 73 collections possess over 90% of all types. Of the 364 collections, 107 hold type specimens of only 1 species or subspecies. Dozens of types are still in private collections. In order to increase their utility, we recommend that the description of type specimens be supplemented with data from high-resolution images and CT-scans, and clear links to tissue samples and DNA sequence data (when available). We request members of the herpetological community provide us with any missing type information to complete the list.

Bone vascular supply in monitor lizards (Squamata: Varanidae): influence of size, growth, and phylogeny.

Bone vascular canals occur irregularly in tetrapods; however, the reason why a species has or lacks bone canals remains poorly understood. Basically, this feature could depend on phylogenetic history, or result from diverse causes, especially cortical accretion rate. The Varanidae, a monophyletic clade that includes species with impressive size differences but similar morphologies, is an excellent model for this question. Cortical vascularization was studied in 20 monitor species, on three bones (femur, fibula, and tibia) that differ in their shaft diameters, and in the absolute growth speed of their diaphyseal cortices. In all species smaller than 398 mm SVL (133-397 mm in sample), bone cortices lack vascular canals, whereas all larger species (460-1,170 mm in sample) display canals. The size 398-460 mm SVL is thus a threshold for the appearance of the canals. The distribution of vascular and avascular bone tissues among species does not precisely reflect phylogenetic relationships. When present, vascular canals always occur in the femur and tibia, but are less frequent, sparser, and thinner in the fibula. Vascular density increases linearly with specific size but decreases exponentially during individual growth. In most species, canal orientation varies between individuals and is diverse in a single section. No clear relationship exists between canal orientation and vascular density. These results suggest that: a) the occurrence and density of bone vascular canals are basically dependant on specific size, not phylogenetic relationships; b) vascular density reflects the absolute growth rates of bone cortices; c) the orientation of vascular canals is a variable feature independent of phylogeny or growth rate.

A new subspecies of Zamenis hohenackeri (Strauch, 1873) (Serpentes: Colubridae) based on morphological and molecular data.

Based on morphological characteristics, two subspecies of the Transcaucasian rat snake (Zamenis hohenackeri) are currently recognized, namely Z. h. tauricus and Z. h. hohenackeri. Both subspecies are repeatedly considered to be conspecific colour morphs, or have even been confused with Z. situla. Although, few studies involved the Transcaucasian rat snake in a phylogenetic approach, none has so far led to any taxonomic changes. We assessed the intraspecific morphological variation and phylogeographic relationships among specimens from different locations across its updated distribution. Our molecular (1191 bp mtDNA, 565 bp nuDNA) and morphological data provide sufficient evidence to support three distinct lineages within the Z. hohenackeri complex with a different arrangement compared to a previous study. These represent the subspecies Z. h. hohenackeri, Z. h. tauricus, and a lineage from southwestern Turkey which is described as a new subspecies. Aspects of historical biogeography and conservation status are briefly discussed.

Annotated checklist and key to the species of amphibians and reptiles inhabiting the northern Peruvian dry forest along the Andean valley of the Marañón River and its tributaries.

A checklist of the amphibians and reptiles of 35 localities situated in the northern Peruvian dry forest valley of the Marañón River and its tributaries, containing 14 species of amphibians and 54 species of reptiles, is provided from data collected between July 2005 and April 2014 during several herpetological surveys and from the literature. Detailed accounts are given for each collected species containing morphometric and scalation data, information on natural history, comments regarding their distribution, the conservation status and key literature. Eleven new species were discovered and described during the survey period. At least five additional taxa might also represent new species but more field work and data collection are necessary to determine their status. For two snake species we provide the first country record and for 23 further species new departamental records are provided.

Hybridization patterns in two contact zones of grass snakes reveal a new Central European snake species.

Recent studies found major conflicts between traditional taxonomy and genetic differentiation of grass snakes and identified previously unknown secondary contact zones. Until now, little is known about gene flow across these contact zones. Using two mitochondrial markers and 13 microsatellite loci, we examined two contact zones. One, largely corresponding to the Rhine region, involves the western subspecies Natrix natrix helvetica and the eastern subspecies N. n. natrix, whereas in the other, more easterly, contact zone two lineages meet that are currently identified with N. n. natrix and N. n. persa. This second contact zone runs across Central Europe to the southern Balkans. Our analyses reveal that the western contact zone is narrow, with parapatrically distributed mitochondrial lineages and limited, largely unidirectional nuclear gene flow. In contrast, the eastern contact zone is very wide, with massive nuclear admixture and broadly overlapping mitochondrial lineages. In combination with additional lines of evidence (morphology, phylogeny, divergence times), we conclude that these differences reflect different stages in the speciation process and that Natrix helvetica should be regarded as a distinct species. We suggest a nomenclatural framework for presently recognized grass snake taxa and highlight the need for reconciling the conflicts between genetics and taxonomy.

Scale Morphology and Micro-Structure of Monitor Lizards (Squamata: Varanidae: Varanus spp.) and their Allies: Implications for Systematics, Ecology, and Conservation.

We analysed scale morphology and micro-structure from five different body regions using scanning electron microscopy (SEM) across all nine recognized subgenera of the monitor lizard genus Varanus including 41 different species investigated. As far as we are aware, this qualitative visual technique was applied by us for the first time to most monitor lizard species and probably also to the primary outgroup and sister species Lanthanotus borneensis. A comprehensive list of 20 scalation characters each with up to seven corresponding character states was established and defined for the five body regions sampled. For the phylogenetic approach, parsimony analyses of the resulting morphological data matrix as well as Bremer and bootstrap support calculations were performed with the software TNT. Our results demonstrate that a variety of micro-ornamentations (i.e., ultra- or micro-dermatoglyphics) as seen in various squamate groups is hardly present in monitor lizards. In several species from six out of nine subgenera, however, we found a honeycomb-shaped micro-structure of foveate polygons. Two further samples of Euprepiosaurus Fitzinger, 1843 exhibit each another unique microscopic structure on the scale surface. Notably, the majority of species showing the honeycombed ultra-structure inhabit arid habitats in Australia, Africa and the Middle East. Therefore, it can be inferred that this microscopic scalation feature, which has also been identified in other desert dwelling lizard species, is taxonomically and ecologically correlated with a xeric habitat type in varanids, too. In addition, the systematic affiliation of V. spinulosus, an endemic monitor lizard species from the Solomon Islands with an extraordinary scale shape, is discussed in the light of current hypotheses about its phylogenetic position within the Varanidae. Due to its unique scalation characteristics, in combination with other morphological evidence, a new monotypic subgenus, Solomonsaurus subgen. nov., is erected for this enigmatic monitor lizard species. Furthermore, we propose a taxonomic splitting of the morphologically and ecologically heterogeneous subgenus Euprepiosaurus comprising the Pacific or mangrove and the tree monitor lizards, respectively, again based on the SEM data. Thus, for the members of the highly arboreal V. prasinus species group erection of a new subgenus, Hapturosaurus subgen. nov., is justified based on the autapomorphic scale shape in concert with further morphological, phylogenetic and ecological evidence. In addition, V. reisingeri originally described as a distinct species is considered conspecific with the wide-spread V. prasinus due to joint synapormorphic features in the ventral scale micro-structure. Consequently, V. prasinus is (again) rendered polytypic with the taxon reisingeri being assigned subspecies status here.        In conclusion, the established scalation characters allow discrimination of single species even among closely-related Varanus species, such as the members of the V. indicus species group. Together with a recently published identification key for Southeast Asian monitor lizards based on macroscopic phenotypic characters (Koch et al. 2013), the SEM-pictures of the present study may serve as additional references for the microscopic identification of CITES-relevant monitor lizard skins and products, respectively.

A new large species of Bitis Gray, 1842 (Serpentes: Viperidae) from the Bale Mountains of Ethiopia.

A new species of viperine viperid snake is described, Bitis harenna sp. nov. The new species is a member of the subgenus Macrocerastes based on it having three scales separating the nasal and rostral shields, and on the combination of 'divisions' of dorsal scale rows on the upper flanks and 'fusions' of rows on the lower flanks. Bitis harenna sp. nov. is distinguished from other members of the subgenus by its unique colour pattern, posterior parietal flange on the lateral wall of the braincase, and possibly by differences in scalation and head proportions. Only a single museum specimen is known, a female collected from 'Dodola' in Ethiopia probably in the late 1960s and previously identified as a possibly unusually coloured and patterned B. parviocula. A live, presumably male, specimen very closely resembling the holotype of Bitis harenna sp. nov. was photographed on the Harenna escarpment of the Bale Mountains National Park, Ethiopia in 2013, providing secure occurrence data and evidence that the holotype is not a uniquely aberrant specimen. A revised key to the species of Bitis in Ethiopia is presented. Aspects of body scalation are compared among species of the subgenus Macrocerastes and between species of Macrocerastes and Bitis, and several systematic characters are highlighted and clarified.

Establishment of age- and sex-adjusted reference data for hand bone mass and investigation of hand bone loss in patients with rheumatoid arthritis treated in clinical practice: an observational study from the DANBIO registry and the Copenhagen Osteoarthritis Study.

BACKGROUND: Rheumatoid arthritis is characterised by progressive joint destruction and loss of periarticular bone mass. Hand bone loss (HBL) has therefore been proposed as an outcome measure for treatment efficacy. A definition of increased HBL adjusted for age- and sex-related bone loss is lacking. In this study, we aimed to: 1) establish reference values for normal hand bone mass (bone mineral density measured by digital x-ray radiogrammetry (DXR-BMD)); and 2) examine whether HBL is normalised in rheumatoid arthritis patients during treatment with tumour necrosis factor alpha inhibitors (TNFI). METHODS: DXR-BMD was measured from hand x-rays in a reference cohort (1485 men/2541 women) without arthritis randomly selected from an urban Danish population. Sex- and age-related HBL/year was estimated. DXR-BMD was measured in rheumatoid arthritis patients (n = 350: at start of TNFI, and ~2 years after TNFI start), of which 135 patients had three x-rays (~2 years prior to TNFI, at start of TNFI, and ~2 years after TNFI start). Individual HBL/year prior to and during TNFI was calculated and compared to reference values. RESULTS: Estimated HBL/year varied strongly with age and sex. Compared to the reference values, 75 % of 135 patients had increased HBL prior to TNFI treatment and 59 % had increased HBL during TNFI treatment (p = 0.17, Chi-squared). In 38 % (38/101) of patients with increased HBL, HBL was normalised during TNFI treatment, whereas 47 % (16/34) of patients with normal HBL prior to TNFI had increased HBL during TNFI treatment. In the 350 patients, increased HBL during TNFI was associated with time-averaged 28-joint disease activity score (odds ratio 1.69 (95 % Confidence Interval 1.34-2.15)/unit increase, p < 0.001), and patients in time-averaged remission had lower HBL than patients without remission (0.0032 vs. 0.0058 g/cm(2)/year; p < 0.001, Mann-Whitney). CONCLUSIONS: We established age- and sex-specific reference values for DXR-BMD in a large cohort without arthritis. HBL was increased in the majority of rheumatoid arthritis patients initiating TNFI in clinical practice, and only normalised in a minority during TNFI.