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Roberta R Pinto - One of the best experts on this subject based on the ideXlab platform.
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moving beyond the surface comparative head and neck myology of threadsnakes epictinae Leptotyphlopidae serpentes with comments on the scolecophidian muscular system
PLOS ONE, 2019Co-Authors: Angele Martins, Paulo Passos, Roberta R PintoAbstract:Studies on the cephalic myology of snakes provide a series of relevant data on their biology and systematics. Despite the great amount of descriptive studies currently available for the group, much of the knowledge remains obscure for most scolecophidian taxa. This study aimed to describe in detail the cephalic (head and neck) myology of members of the tribe Epictinae, Leptotyphlopidae. We provide the first report of the presence of extrinsic ocular muscles, and a double Musculus pterygoideus acessorius in Leptotyphlopidae. A well-developed M. levator anguli oris is exclusive to the subtribes Renina and Epictina, being reduced in Tetracheilostomina species. Both inter- and intraspecific variations are reported for the head and neck muscles, and such results provide additional data and raise an interesting discussion on the neck-trunk boundaries in snakes. We also provide a discussion on the terminology of a few head muscles in Leptoyphlopidae in comparison to the other lineages of ´Scolecophidia´ (Anomalepididae and Typhlopoidea).
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taxonomic notes on the genus siagonodon peters 1881 with a report on morphological variation in siagonodon cupinensis bailey and carvalho 1946 serpentes Leptotyphlopidae
Copeia, 2018Co-Authors: Barbara Cristina S Francisco, Roberta R Pinto, Daniel S FernandesAbstract:The family Leptotyphlopidae comprises about 120 species allocated in 12 genera including Siagonodon, the latter with four currently recognized species. Here we propose new diagnostic characters for the genus Siagonodon based on the analysis of variation of external morphology and comparisons with related taxa. In order to evaluate the diagnostic characters of the genus Siagonodon, representatives of other genera of the tribe Epictini occurring in South America were also analyzed (Epictia, Rena, and Trilepida). We examined 14 species of the family Leptotyphlopidae and analyzed 67 characters of external morphology. We propose six new diagnostic characters for the genus Siagonodon, including: rostral scale with enlarged base, terminal spine reduced or absent, and straight snout in lateral view. Furthermore, we provide new data on morphological variation and geographical distribution of the poorly known Siagonodon cupinensis, expanding the diagnosis of this taxon and improving comparisons with congeners.
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morphological variation of trilepida macrolepis peters 1857 with reappraisal of the taxonomic status of rena affinis boulenger 1884 serpentes Leptotyphlopidae epictinae
Zootaxa, 2017Co-Authors: Roberta R Pinto, Ronaldo FernandesAbstract:We report on the morphological variation (meristic, morphometric, pholidosis, and color pattern characters) and sexual dimorphism of Trilepida macrolepis . We also took the opportunity to redescribe the holotype of Rena affinis in an effort to evaluate its taxonomic status. Based on the congruence of characters from external morphology, we transfer Stenostoma affine to the genus Trilepida . We also discuss the Andean specimens previously refereed to Trilepida affinis and Trilepida macrolepis and provide an identification key for the genus Trilepida .
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osteology and cartilaginous elements of trilepida salgueiroi amaral 1954 scolecophidia Leptotyphlopidae
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, 2015Co-Authors: Angele Martins, Roberta R Pinto, Felipe Franco Curcio, Luciana O RamosAbstract:Morphological and anatomical studies on the Leptotyphlopidae have increased in the past 10 years, providing important data on the systematics of this group, mainly focused on the skull and lower jaw morphology. However, most studies are based on a single specimen, rarely combining more than one single method of assessing morphological information. Therefore, several data on postcranial morphology, sexual dimorphism, and ontogenetic and intraspecific variation of leptotyphlopids remain poorly understood. Herein, we provide a detailed description of the cranial and postcranial skeleton of Trilepida salgueiroi based on more than 20 specimens (including males, females and juveniles), as well as a description of osteology and cartilaginous elements through the use of combined methodologies such as X-ray scanning, high resolution CT-scanning, and clearing and staining of articulated and disarticulated specimens. We also provide data on the presence/absence of dimorphic and intraspecific variation of the observed characters. The presence of a statolithic mass in the cavum vestibuli differs from the pattern found in other scolecophidians. A correlation of dorsal vertebrae with ventral and subcaudal scales was found (1:1), as well as total number of vertebrae with middorsal scales (1:1), thoracolumbar vertebrae and ventral scales (1:1), and a higher number of caudal vertebra with subcaudal scales (1.23:1). Intraspecific variation was found in several elements of the skull, lower jaw, pelvic girdle and vertebral number, but no evidence of sexual dimorphism was found in any of the species characters analysed. The homologies of several elements are discussed, although still remaining poorly understood and unknown. Anat Rec, 298:1722–1747, 2015. © 2015 Wiley Periodicals, Inc.
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taxonomy of epictia munoai orejas miranda 1961 squamata serpentes Leptotyphlopidae
Zootaxa, 2012Co-Authors: Barbara Cristina S Francisco, Roberta R Pinto, Daniel S FernandesAbstract:The wormsnakes Leptotyphlopidae include the smallest and thinnest snakes of the world. This group has historically fewtaxonomic studies and the descriptions of taxa in general are superficial, frequently preventing an accurate identification.This family includes the genus Epictia with many representatives with taxonomic major issues, including Epictia munoai. We redescribe and compare E. munoai with other related cisandine species in order to evaluate its taxonomic status con-sidering the morphological analysis of specimens. A table with some diagnostic characters of each species is presented. Epictia munoai is distinguished from other related species mostly by low number of middorsal and midventral scales, and is distributed in coastal areas in southern Brazil, Uruguay and northeastern Argentina.
Angele Martins - One of the best experts on this subject based on the ideXlab platform.
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a century of waiting description of a new epictia gray 1845 serpentes Leptotyphlopidae based on specimens housed for more than 100 years in the collection of the natural history museum vienna nmw
PeerJ, 2019Co-Authors: Claudia Koch, Angele Martins, Silke SchweigerAbstract:: We describe a new species of Epictia based on eight specimens from Nicaragua collected and housed in the collection of the Natural History Museum Vienna for more than a century. The species differs from the congeners by the combination of external morphological characters: midtail scale rows 10; supralabials two, anterior one large and in broad contact with supraocular; infralabials four; subcaudals 14-19; middorsal scale rows 250-267; supraocular scales present; frontal scale distinct; striped dorsal color pattern with more or less triangular dark blotches on each scale; small white blotch in anterior part of dorsal surface of rostral present in five out of six specimens (two further specimens are lacking their heads); terminal spine and adjacent scales white. Eidonomic species separation from other Epictia spp. is also supported by a few qualitative and quantitative differences in vertebrae count and morphology. The new species is putatively assigned to the Epictia phenops species group based on external morphological characters and distribution.
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moving beyond the surface comparative head and neck myology of threadsnakes epictinae Leptotyphlopidae serpentes with comments on the scolecophidian muscular system
PLOS ONE, 2019Co-Authors: Angele Martins, Paulo Passos, Roberta R PintoAbstract:Studies on the cephalic myology of snakes provide a series of relevant data on their biology and systematics. Despite the great amount of descriptive studies currently available for the group, much of the knowledge remains obscure for most scolecophidian taxa. This study aimed to describe in detail the cephalic (head and neck) myology of members of the tribe Epictinae, Leptotyphlopidae. We provide the first report of the presence of extrinsic ocular muscles, and a double Musculus pterygoideus acessorius in Leptotyphlopidae. A well-developed M. levator anguli oris is exclusive to the subtribes Renina and Epictina, being reduced in Tetracheilostomina species. Both inter- and intraspecific variations are reported for the head and neck muscles, and such results provide additional data and raise an interesting discussion on the neck-trunk boundaries in snakes. We also provide a discussion on the terminology of a few head muscles in Leptoyphlopidae in comparison to the other lineages of ´Scolecophidia´ (Anomalepididae and Typhlopoidea).
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Unveiling diversity under the skin: comparative morphology study of the cephalic glands in threadsnakes (Serpentes: Leptotyphlopidae: Epictinae)
Zoomorphology, 2018Co-Authors: Angele Martins, Paulo Passos, Roberta PintoAbstract:The subfamily Epictinae contains about 75 currently recognized species of strictly fossorial snakes distributed along the Neotropics (subtribe Renina) and Equatorial Africa (subtribe Rhinoleptini). Although several studies have addressed some internal phenotypic characters complexes for the taxa included in this subfamily, most of the available data are limited to skull morphology and visceral topology. Additionally, many studies, when reporting glandular information, do not provide comparative data obtained through of a replicable methodology. In this study, we aimed to describe in detail the macrostructure of the cephalic glands for the members of the subfamily Epictinae. We provide herein the first report of a rictal gland for the infraorder Scolecophidia, as well as the first report of an infralabial accessory gland for the family Leptotyphlopidae. We highlight the utility of glandular qualitative characters for the systematics and even alpha taxonomy of this group of snakes that frequently exhibits a conserved external morphology. Furthermore, we also discuss possible functional aspects related to the Harderian gland in association to the M. adductor externus superficialis based on macrostructure observations of Epictinae specimens.
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osteology and cartilaginous elements of trilepida salgueiroi amaral 1954 scolecophidia Leptotyphlopidae
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, 2015Co-Authors: Angele Martins, Roberta R Pinto, Felipe Franco Curcio, Luciana O RamosAbstract:Morphological and anatomical studies on the Leptotyphlopidae have increased in the past 10 years, providing important data on the systematics of this group, mainly focused on the skull and lower jaw morphology. However, most studies are based on a single specimen, rarely combining more than one single method of assessing morphological information. Therefore, several data on postcranial morphology, sexual dimorphism, and ontogenetic and intraspecific variation of leptotyphlopids remain poorly understood. Herein, we provide a detailed description of the cranial and postcranial skeleton of Trilepida salgueiroi based on more than 20 specimens (including males, females and juveniles), as well as a description of osteology and cartilaginous elements through the use of combined methodologies such as X-ray scanning, high resolution CT-scanning, and clearing and staining of articulated and disarticulated specimens. We also provide data on the presence/absence of dimorphic and intraspecific variation of the observed characters. The presence of a statolithic mass in the cavum vestibuli differs from the pattern found in other scolecophidians. A correlation of dorsal vertebrae with ventral and subcaudal scales was found (1:1), as well as total number of vertebrae with middorsal scales (1:1), thoracolumbar vertebrae and ventral scales (1:1), and a higher number of caudal vertebra with subcaudal scales (1.23:1). Intraspecific variation was found in several elements of the skull, lower jaw, pelvic girdle and vertebral number, but no evidence of sexual dimorphism was found in any of the species characters analysed. The homologies of several elements are discussed, although still remaining poorly understood and unknown. Anat Rec, 298:1722–1747, 2015. © 2015 Wiley Periodicals, Inc.
Peter S Harlow - One of the best experts on this subject based on the ideXlab platform.
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life history strategies in basal snakes reproduction and dietary habits of the african thread snake leptotyphlops scutifrons serpentes Leptotyphlopidae
Journal of Zoology, 2000Co-Authors: Jonathan K Webb, William R Branch, Richard Shine, Peter S HarlowAbstract:Information on the biology of `primitive' blind snakes can help clarify the origin of ecological traits typical of `higher' snakes. We examined and dissected 360 museum specimens to obtain information on morphology, dietary habits, and reproduction of two subspecies of an African thread snake, Leptotyphlops s. scutifrons and L. s. conjunctus. These small (to 225 mm long), slender-bodied (body diameters < 5 mm) burrowing snakes are common throughout southern Africa. In both subspecies, females grow larger than males and have relatively shorter tails. Reproduction is seasonal, with vitellogenesis in spring (October), oviposition in summer (December±February), and hatching in autumn (April±May). Clutch sizes are small (1±3 eggs), and hatchling thread snakes are large relative to maternal body size. Despite the abundance of termites on the African continent, L. scutifrons feeds almost entirely on the larvae and pupae of small ants. Both races fed infrequently, and took large numbers of prey (up to 350 items) in a single meal. A shift from `lizard-like' to `snake-like' trophic biology is evident within the Scolecophidia: two species of North American thread snake feed frequently on a taxonomically diverse array of small prey; African L. scutifrons feed infrequently on small prey, but take large meals composed of numerous prey items; and one highly derived Melanesian typhlopid (Acutyphlops subocularis) feeds infrequently on large elongate prey. In contrast to popular theory, our data suggest that the evolutionary shift to infrequent feeding among snakes did not initially require a change from small to large prey.
Bayram Göçmen - One of the best experts on this subject based on the ideXlab platform.
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Morphology of peripheral blood cells from various Turkish snakes
2020Co-Authors: Hüseyin Arikan, Bayram Göçmen, Mehmet K. AtatürAbstract:The present study is on the morphologies and sizes of peripheral blood cells (erythrocytes, leucocytes and thrombocytes) of thirty two Turkish snake species from blood smears, stained with Wright's stain. The investigated species and their families are as follows: Leptotyphlopidae (Leptotyphlops macrorhynchus (Jan 1861)), Typhlopidae (Typhlops vermicularis Merrem 1820), Boidae (Eryx jaculus (Linnaeus 1758)), Colubridae (Dolichophis jugularis (Linnaeus 1758), D. schmidti (Nikolsky 1909), D. caspius (Gmelin 1789), C. ventromaculatus Gray 1834, Hemorrhois nummifer (Reuss 1834), H. ravergieri (Menetries 1832), Platyceps collaris (Muller 1878), P. najadum (Eichwald 1831), Zamenis hohenackeri (Strauch 1873), Natrix natrix (Linnaeus 1758), N. tessellata (Laurenti 1768), Eirenis rothi Jan 1863, E. levantinus Schmidtler 1993, E. coronella (Schlegel 1837), E. barani Schmidtler 1988, E. eiselti Schmidtler & Schmidtler 1978, E. decemlineatus (Dumeril & Bibron 1854), E. modestus (Martin 1838), Rhynchocalamus melanocephalus (Jan 1862), Telescopus fallax (Fleischmann 1831), T. nigriceps (Ahl 1924), Malpolon monspessulanus (Hermann 1804), Spalerosophis diadema (Schlegel 1837), Viperidae (Montivipera xanthina (Gray 1849), M. wagneri (Nilson & Andren 1984), M. albizona (Nilson,, Andren & Flardh 1990), Vipera eriwanensis (Reuss 1933), Macrovipera lebetina (Linnaeus 1758)) and Elapidae (Walterinnesia aegyptia Lataste 1887).
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Taxonomical comments on Sudan beaked worm snake, Leptotyphlops macrorhynchus (Jan&Sordelli, 1860) (Serpentes: Leptotyphlopidae) from Anatolia, Turkey
2020Co-Authors: Mehmet Zülfü Yildiz, Bayram GöçmenAbstract:In this study, 63 specimens of Leptotyphlops macrorhynchus collected from 14 localities were examined in terms of morphometric measurements and pholidosis characteristics. Eleven localities were found on the east side of the Euphrates River, an important dispersal barrier for animals in Anatolia and three localities on the west side of the river. According to Mann-Whitney U test dorsalia numbers showed differences between the east and west side population of the Euphrates River (p
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taxonomical comments on sudan beaked worm snake leptotyphlops macrorhynchus jan sordelli 1860 serpentes Leptotyphlopidae from anatolia turkey
2009Co-Authors: Mehmet Zülfü Yildiz, Bayram GöçmenAbstract:In this study, 63 specimens of Leptotyphlops macrorhynchus collected from 14 localities were examined in terms of morphometric measurements and pholidosis characteristics. Eleven localities were found on the east side of the Euphrates River, an important dispersal barrier for animals in Anatolia and three localities on the west side of the river. According to Mann-Whitney U test dorsalia numbers showed differences between the east and west side population of the Euphrates River (p<0.05). The results of the student t test also showed two morphometric characters (diameter at midbody and diameter at tail) and two ratios different between the populations. This study also extends the known distribution area of the species by recording new localities.
Blair S Hedges - One of the best experts on this subject based on the ideXlab platform.
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molecular phylogeny and taxonomy of the epictia goudotii species complex serpentes Leptotyphlopidae epictinae in middle america and northern south america
PeerJ, 2016Co-Authors: James R Mccranie, Blair S HedgesAbstract:Here we review the systematics of the threadsnakes of the Epictia goudotii Species complex in Middle and northern South America using external morphology and molecular data. Two species, Epictia goudotii and E. magnamaculata, are currently recognized from that region, but we provide evidence for recognizing, as species, three other nominal forms usually treated as subspecies of E. goudotii: E. ater, E. bakewelli, and E. phenops. Thus, together with E. columbi (Bahamas), we recognize six species in the Epictia goudotii Species complex. Because E. albifrons from northern South America has been confused with E. goudotii in the past, we also briefly discuss the taxonomic status of that species and its apparent close relative E. tenella, which are not members of the E. goudotii complex.
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molecular phylogeny classification and biogeography of snakes of the family Leptotyphlopidae reptilia squamata
Zootaxa, 2009Co-Authors: Solny A Adalsteinsson, William R Branch, Sebastien Trape, Laurie J Vitt, Blair S HedgesAbstract:The family Leptotyphlopidae (116 species) includes the smallest and thinnest species of snakes, often called threadsnakes (or wormsnakes). They are burrowing, have small eyes, and they feed on several life history stages of social insects. Leptotyphlopids have a West Gondwanan distribution, occurring primarily in Africa and the Neotropics (South America, Middle America, and the West Indies). The family is one of the most poorly known of all terrestrial vertebrates from the standpoint of systematics and ecology. No published phylogenetic studies of higher-level relationships exist, either from morphological or molecular data. Here we present DNA sequence analyses of 91 individuals representing 34 recognized species of leptotyphlopids, from nine mitochondrial and nuclear genes. The results show divergences among living lineages as early as the mid-Cretaceous, 92 (113–75) million years ago (Ma) and evidence that the breakup of West Gondwana into South America and Africa, and the separation of West Africa from South and East Africa by high sea levels in the Cretaceous, influenced the biogeographic history of the family through isolation. A Late Cretaceous (78 Ma; 98–63 Ma) transatlantic dispersal from West Africa to South America may explain the origin of the monophyletic New World radiation. Mid-Cenozoic divergences among Middle and North American species indicate that leptotyphlopids dispersed to those regions from South America, by rafting over water, prior to the emergence of the Isthmus of Panama. A revised classification recognizes two subfamilies, Epictinae subfam. nov. (New World and Africa) and Leptotyphlopinae (Africa, Arabia, and Southwest Asia). Within the Epictinae we recognize two tribes (Epictini trib. nov. and Rhinoleptini trib. nov.), three subtribes (Epictina subtrib. nov., Tetracheilostomina subtrib. nov., and Renina subtrib. nov.), and eight genera (Epictia, Guinea gen. nov., Mitophis gen. nov., Rena, Rhinoleptus, Siagonodon, Tetracheilostoma, and Tricheilostoma). Three tribes are recognized within the Leptotyphlopinae (Epacrophini trib. nov., Myriopholini trib. nov., and Leptotyphlopini trib. nov.) and four genera (Epacrophis gen. nov., Myriopholis gen. nov., Leptotyphlops, and Namibiana gen. nov.). The significant non-monophyly of some species and the estimated long period of time (tens of millions of years) separating populations of currently recognized species indicate that an unusually large number of species exist that are unrecognized. This combined with small distributions and high levels of deforestation in these areas argue for increased awareness of leptotyphlopids and other burrowing reptiles in conservation planning.
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at the lower size limit in snakes two new species of threadsnakes squamata Leptotyphlopidae leptotyphlops from the lesser antilles
Zootaxa, 2008Co-Authors: Blair S HedgesAbstract:Islands are viewed as natural evolutionary laboratories for terrestrial organisms because they have boundaries that limit dispersal and often reveal evolutionary patterns and mechanisms. One such pattern is that the smallest and largest species of different types of tetrapod animals are frequently found on islands. Here I describe two new diminutive species of snakes of the genus Leptotyphlops from the Lesser Antilles: one from Saint Lucia and the other from Barbados. The one from Barbados is the smallest species of snake and has a total adult length of approximately 100 mm. Limited evidence indicates a clutch size of one and a greatly elongated egg shape (length /width). Comparison of egg shapes in snakes indicates that the shape is a packaging phenomenon, related primarily to the shape of the available body cavity and clutch size. For a clutch size of one, expected egg shape is eight whereas expected egg shape drops to two at a clutch size of ten. The body shape of snakes, defined as snout-to-vent length divided by width, also varies and influences the shape of snake eggs. The smallest snakes are typically stout-bodied with shapes of 30–35 whereas the longest snakes usually are more elongate, with shapes of 45–50. The allometry of organ size also affects clutch size and shape, because the smallest snakes have the smallest proportion of body cavity space available for reproduction. The best explanation for the observation of body size extremes on islands is that colonizing species have adapted to open ecological niches that would otherwise be occupied on the mainland. Island colonists encounter novel environments and reduced interspecific competition, allowing species to evolve physical traits, including extremes in size, not normally seen on continents. However, the lower limit of adult size appears to be constrained by the allometry of morphology, physiology, and reproduction. The smallest tetrapods have small clutches, usually one egg or young, and offspring that are relatively large. In the smallest snakes, offspring are one-half of the length of adults, compared with 10% adult length in the case of large species of snakes. Thus the evolutionary tradeoff between number and size of offspring appears to have reached a size boundary in these species, limiting the evolution of yet smaller species.