Morphological variation, polymorphism, and Taxonomy of the Atractus torquatus complex (Serpentes: Dipsadidae)

Zootaxa ◽  
2012 ◽  
Vol 3407 (1) ◽  
pp. 1 ◽  
Author(s):  
PAULO PASSOS ◽  
ANA L. C. PRUDENTE
Keyword(s):  
Morphological Variation ◽  
Geographical Variation ◽  
Amazon Basin ◽  
Landscape Evolution ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Colour Pattern ◽  
Guiana Shield ◽  
Qualitative And Quantitative

The taxonomic status of Atractus torquatus is revised on the basis of concordance between quantitative and qualitativeanalyses of morphological characters (meristic, morphometric, colour pattern, and hemipenis) throughout its geographicaldistribution. We propose the synonymy of Atractus davidhardi, A. janethae, and A. lucilae based on wide overlap of mor-phological characters (qualitative and quantitative). Despite some differences in the frequency of the number of suprala-bials, infralabials and maxillary teeth among A. torquatus populations, we find that these characters exhibit a high levelof polymorphism and therefore cannot unambiguously diagnose Guiana Shield and Amazon Basin populations. Addition-ally, we discuss the polymorphism and geographical variation in A. torquatus and its appropriateness for hypotheses of landscape evolution in Amazonia.

The status of the races of the graceful crag lizard, Pseudocordylus capensis, from South Africa

1992 ◽  
Vol 13 (2) ◽  
pp. 109-119 ◽  
Author(s):  
Y.M. Herselman ◽  
J.H. Van Wyk ◽  
P. le F.N. Mouton
Keyword(s):  
South Africa ◽  
Geographical Variation ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Distribution Range ◽  
The Status ◽  
Formal Taxonomy ◽  
New Distribution

AbstractTo evaluate the taxonomic status of the races of the graceful crag lizard, Pseudocordylus capensis, geographical variation in 44 external morphological characters was determined, using 97 specimens from 31 localities. Two different epiphenotypes predominate in the northern and southwestern parts of the distribution range. These epiphenotypes are, however, connected by a continuum of variation. It is therefore suggested that the recognition of races be abandoned in the formal taxonomy. Several new distribution records for the species are provided.

Morphological variation in the genus Juliomys (Rodentia: Cricetidae: Sigmodontinae) and taxonomic status of Juliomys anoblepas (Winge 1887) from the Quaternary of Southeast Brazil

Zootaxa ◽  
2020 ◽  
Vol 4861 (3) ◽  
pp. 429-443
Author(s):  
CAROLINA PIRES ◽  
MARCELO WEKSLER ◽  
CIBELE R. BONVICINO
Keyword(s):  
Principal Component Analysis ◽  
Morphological Variation ◽  
Morphological Analysis ◽  
Principal Component ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
The Other ◽  
Anterior Portion ◽  
Living Species ◽  
Qualitative Characters

The region of Lagoa Santa, Minas Gerais, Brazil, is one of the most important karstic areas of the Brazilian Quaternary due to the faunistic diversity of living and extinct forms. Among them, some taxa remain poorly studied, as is the case of Calomys anoblepas Winge 1887. Despite the recent allocation of the taxon within Juliomys, its description and morphological analysis are condensed, based on comparative few specimens and on few informative characters. In this study, we investigate characters proposed to distinguish species of Juliomys, and reevaluate the taxonomic status of the fossil Juliomys anoblepas. We analyzed 80 cranio-dental morphological characters in 233 specimens represented by the four species currently recognized: J. pictipes (Osgood 1933), J. rimofrons Oliveira & Bonvicino 2002, J. ossitenuis Costa, Pavan, Leite & Fagundes 2007, and J. ximenezi Christoff, Vieira, Oliveira, Gonçalves, Valiati & Tomasi 2016. We also performed principal component analysis on eight craniodental measurements available for the J. anoblepas hypodigm. The review of morphological systems and the evaluation of the characters used in the literature revealed that there are no diagnostic characters in the anterior portion of the skull and in the molar series of Juliomys, being difficult to differentiate the fossil from the other living species. Only six qualitative characters were variable and applicable to the hypodigm of J. anoblepas. Characters are polymorphic, invariable, or the fossil is not sufficiently complete to determinate its states. The taxon could not be morphometrically differentiated from J. pictipes and J. ossitenuis. Based on the results presented herein, we consider J. anoblepas as a nomen dubium and restrict its name to the taxon’s hypodigm. 

scholarly journals Beyond the carapace: skull shape variation and morphological systematics of long-nosed armadillos (genus Dasypus)

2017 ◽  
Author(s):  
Lionel Hautier ◽  
Guillaume Billet ◽  
Benoit De Thoisy ◽  
Frédéric Delsuc
Keyword(s):  
Morphological Variation ◽  
Distinct Species ◽  
Morphological Characters ◽  
Molecular Data ◽  
Guiana Shield ◽  
Shape Variation ◽  
Skull Morphology ◽  
Geometric Morphometric ◽  
Skull Shape ◽  
Shape And Size

Background. The systematics of long-nosed armadillos (genus Dasypus) has been mainly based on a handful of external morphological characters and classical measurements. Here, we studied the pattern of morphological variation in the skull of long-nosed armadillos species, with a focus on the systematics of the widely distributed nine-banded armadillo (D. novemcinctus). Methods. We present the first exhaustive 3D comparison of the skull morphology within the genus Dasypus, based on µCT-scans. We used geometric morphometric approaches to explore the patterns of the intra- and interspecific morphological variation of the skull with regard to several factors such as taxonomy, geography, allometry, and sexual dimorphism. Results. We show that the shape and size of the skull vary greatly between Dasypus species, with D. pilosus representing a clear outlier compared to other long-nosed armadillos. The study of the cranial intraspecific variation in D. novemcinctus evidences clear links to the geographic distribution and argue in favour of a revision of past taxonomic delimitations. Our detailed morphometric comparisons detected previously overlooked morphotypes of nine-banded armadillo, especially a very distinctive unit circumscribed to the Guiana Shield. Discussion. As our results are congruent with recent molecular data and analyses of the structure of paranasal sinuses, we propose that D. novemcinctus should be regarded either as a polytypic species (with three to four subspecies) or as a complex of several distinct species.

scholarly journals Two new charismatic Pristimantis species (Anura: Craugastoridae) from the tepuis of the "Lost World" (Pantepui region, South America)

2013 ◽  
Author(s):  
Philippe J.R. Kok
Keyword(s):  
New Species ◽  
South America ◽  
Conservation Status ◽  
Morphological Characters ◽  
Colour Pattern ◽  
Guiana Shield ◽  
Dorsal Skin ◽  
Skin Texture ◽  
Two New Species ◽  
Table Mountains

Two new colourful species of direct-developing frogs of the genus Pristimantis are described from the summit of two isolated tepuis (sandstone table mountains) in the Eastern Pantepui District of the Guiana Shield highlands. Pristimantis jamescameroni sp. nov. is described from the summit of Aprada-tepui from 2557-2571 m elevation, and P. imthurni sp. nov. is described from the summit of Ptari-tepui at 2471 m elevation. Both species share the absence of a differentiated tympanic membrane and external tympanic annulus (but presence of tiny pharyngeal ostia), the presence of nuptial pads in males, and the presence of lateral fringes on fingers and toes, a combination of characters that immediately distinguishes them from all other known Pantepui congeners. The two new species are morphologically similar to each other and are phylogenetically closely related, but they can be distinguished based on colour pattern and morphological characters such as head proportions, dorsal skin texture, and condition of the supratympanic fold. The IUCN conservation status of the new species is considered as Endangered (EN) owing to their apparent very restricted ranges. The number of described Pristimantis species occurring exclusively on tepui (and faunistically related granitic mountains) summits and upper slopes now reaches eleven.

To be or not to be tchernovi: a taxonomic revision of the snake genus Micrelaps (Squamata: Serpentes), in Israel

Zootaxa ◽  
2020 ◽  
Vol 4881 (2) ◽  
pp. 290-306
Author(s):  
SIMON JAMISON ◽  
EREZ MAZA ◽  
GUY SINAIKO ◽  
KARIN TAMAR ◽  
ALEX SLAVENKO ◽  
...  
Keyword(s):  
Morphological Variation ◽  
Taxonomic Status ◽  
Taxonomic Revision ◽  
Molecular Data ◽  
Colour Pattern ◽  
Clinal Variation ◽  
Jordan Valley ◽  
Temperature And Precipitation ◽  
Morphological And Molecular Data ◽  
Colour Patterns

The enigmatic snake genus Micrelaps has uncertain phylogenetic affinities. The type species of the genus, Micrelaps muelleri, inhabits the Southern Levant. Snakes inhabiting the Jordan River Valley just south of the Sea of Galilee have been described as a new species, Micrelaps tchernovi, based on their distinct colour patterns, despite M. muelleri being well known to be variable in colour-pattern traits. Here we use morphological and molecular data to examine the taxonomic status and phylogenetic affinity of Levantine Micrelaps. We show that all scalation, colour, and pattern-related traits are extremely variable across the range of these snakes. Some morphological features show clinal variation related to temperature and precipitation, and snakes with a ‘tchernovi’ morph are merely at one end of a continuum of morphological variation. Both ‘classical muelleri’ and ‘tchernovi’ morphs occur in syntopy in the Jordan Valley and elsewhere in Israel. Against this background of high morphological variation, neutral genetic markers show almost no differentiation between snakes, no genetic structure is evident across populations, and no differences are to be found between the two putative species. We conclude that Levantine Micrelaps belongs to a single, morphologically variable, and genetically uniform species, Micrelaps muelleri, of which M. tchernovi is a junior synonym.

GENETICAL AND MORPHOLOGICAL VARIATION IN THE EELPOUT ZOARCES VIVIPARUS

1981 ◽  
Vol 23 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Freddy Bugge Christiansen ◽  
Birte Vivi Nielsen ◽  
Vibeke Simonsen
Keyword(s):  
Morphological Variation ◽  
Geographical Variation ◽  
Morphological Characters ◽  
Pectoral Fin ◽  
Local Populations ◽  
Dorsal Fin ◽  
Zoarces Viviparus ◽  
Fin Rays ◽  
Morphological Composition ◽  
Pectoral Fin Rays

The geographical variation in genotypic and morphological composition is compared for populations of the eelpout, Zoarces viviparus (L.), in Mariager Fjord, Denmark. The morphological characters are number of vertebrae, dorsal fin hard rays, pectoral fin rays, and pigment spots of dorsal fin. The geographical variation in these traits agrees well with that described by Johs. Schmidt half a century ago. The electrophoretical variation at five enzyme loci: Ada, EstIII, Got, PgmI and PgmII is described. The scale of differentiation is comparable for the two classes of traits, and differentiations between local populations down to a distance of about 10 km are shown.

Taxonomy of the Threadsnakes of the tribe Epictini (Squamata: Serpentes: Leptotyphlopidae) in Colombia

Zootaxa ◽  
2019 ◽  
Vol 2724 (1) ◽  
pp. 1 ◽  
Author(s):  
ROBERTA RICHARD PINTO ◽  
PAULO PASSOS ◽  
JOSÉ RANCES CAICEDO PORTILLA ◽  
JUAN CAMILO ARREDONDO ◽  
RONALDO FERNANDES
Keyword(s):  
Taxonomic Status ◽  
Taxonomic Revision ◽  
The United States ◽  
Morphological Characters ◽  
Neotropical Region ◽  
Systematic Position ◽  
Colour Pattern ◽  
Previous Attempt ◽  
Additional Material ◽  
Species Descriptions

Threadsnakes of the tribe Epictini are endemic to the New World, occurring from the United States to Argentina, mostly in the Neotropical region. Currently, the taxonomic status of most species is unclear and there has been no previous attempt of a comprehensive taxonomic revision of Neotropical taxa. Taxonomy of the group is a difficult task due to the paucity of geographic samples, general homogeneous morphology and brevity of species descriptions. Therefore, the only way to address the taxonomic status of existing names is through detailed characterization of the types and the search for additional material of the poorly known species. In this study, we evaluated the taxonomic status of the Colombian threadsnakes and report on geographical variation of meristic, morphometric, colour pattern, and hemipenis characters. On the basis of available samples we recognize the following species in Colombia: Epictia goudotii, E. magnamaculata, E. signata, Rena nicefori, Tricheilostoma brevissimum, T. dugandi, T. joshuai and T. macrolepis. We discuss the systematic position of Rena nicefori and propose its allocation in the genus Tricheilostoma based on a unique combination of morphological characters. Furthermore, we provide a key to the representatives of the tribe Epictini in Colombia.

Phenotypic variation in Heremites vittatus (Olivier, 1804) (Sauria: Scincidae) from Iran and Turkey

Zootaxa ◽  
2021 ◽  
Vol 5004 (1) ◽  
pp. 181-192
Author(s):  
NASRULLAH RASTEGAR-POUYANI ◽  
YUSUF KUMLUTAŞ ◽  
AZIZ AVCI ◽  
KAMIL CANDAN ◽  
CETIN ILGAZ ◽  
...  
Keyword(s):  
Morphological Variation ◽  
Phenotypic Variation ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Zagros Mountains ◽  
Iranian Populations

According to a large morphological dataset of specimens from Turkey to Iran and based on several morphological analyses, the Iranian populations of the skink Heremites vittatus are separated from other populations of this taxon in Turkey. The values of most of morphological characters were higher in the Turkish populations. Morphological variation among populations of H. vittatus (Olivier, 1804) from Turkey and the western slopes of the Zagros Mountains in Kermanshah province in Iran may be the result of different dispersal and vicariance events. Comparison the current study dataset with specimens from Egypt can definite the taxonomic status of Iranian and Turkish populations.

Etudes sur les Acanthodactyles de Tunisie: VII - Les Acanthodactyles de l'Extrême-Sud tunisien

1985 ◽  
Vol 6 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Ivan Ineich ◽  
Charles P. Blanc
Keyword(s):  
Morphological Variation ◽  
Sand Dunes ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Multidimensional Analysis ◽  
Diagnostic Use ◽  
Southern Tunisia ◽  
White Spots ◽  
Habitat Difference ◽  
Field Stations

AbstractA multidimensional analysis of 34 characters of the colouring and scale pattern, providing 101 mathematical variables, applied to 77 Acanthodactylus collected in ten field stations in the Saharien Far-South of Tunisia, reveals a gradual and continuous morphological variation from populations of Acanthodactylus inornatus (with the back and sides of their body blackly reticulated and short legs) to populations with a A. longipes habitus (orange light body with small dorsal white spots, faint or nul black marks on their flanks and longer legs). Variation axis, approximately directed from North to South, also express an habitat difference between the populations dwelling on the reg nebkhas and sandy knolls in the beds and edges of the rivers (oueds) and those restricted to the high sand dunes of the Great Eastern Erg. The taxonomic status of the Acanthodactylus populations living in the Southern Tunisia should obviously be revised in relation with a high and mostly uncorrelated variability of the morphological characters of diagnostic use.

Species delimitations in the Atractus collaris complex (Serpentes: Dipsadidae)

Zootaxa ◽  
2018 ◽  
Vol 4392 (3) ◽  
pp. 491 ◽  
Author(s):  
PAULO PASSOS ◽  
ANA L. C. PRUDENTE ◽  
LUCIANA O. RAMOS ◽  
JOSÉ RANCES CAICEDO-PORTILLA ◽  
JOHN D. LYNCH
Keyword(s):  
Geographical Distribution ◽  
Geographical Variation ◽  
Morphological Character ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Color Pattern ◽  
Species Group ◽  
Wide Geographical Distribution ◽  
Dichotomous Key ◽  
Morphological Distinction

We reassessed the taxonomic status of the species in the Atractus collaris complex (A. alphonsehogei, A. collaris, A. limitaneus, and A. gaigeae) on the basis of congruence between quantitative and qualitative morphological characters (meristic, morphometric, color pattern, hemipenis, and scale microdematoglyphics) along its wide geographical distribution. Our results support the recognition of three species with apparently fixed diagnostic characters. We propose the synonymization of Atractus limitaneus with A. collaris based on the wide overlap of all morphological character systems here analyzed, as well as on the basis of examination of the holotype and two topotypes of A. limitaneus. Finally, we discuss the geographical variation and morphological distinction of A. alphonsehogei, A. collaris and A. gaigeae. Furthermore, we provide a dichotomous key for all recognized species in the A. collaris species group. 

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