scholarly journals Are subspecies (of Eira barbara) real?

2020 ◽  
Vol 101 (5) ◽  
pp. 1410-1425
Author(s):  
Mauro Ignacio Schiaffini
Keyword(s):  
Conceptual Framework ◽  
Size Variation ◽  
Species Level ◽  
Morphological Data ◽  
Modern Concept ◽  
Climate Data ◽  
Skull Morphology ◽  
Skull Shape ◽  
Components Analysis ◽  
Eira Barbara

Abstract The subspecies concept is one of the most controversial in Linnean taxonomy. In the past, subspecies were described without a clear conceptual framework, triggering confusion and motivating criticism of the very concept of a subspecies. At present, subspecies are conceived as aggregates of populations that are geographically isolated, are composed of interfertile individuals, and are morphologically diagnosable. The tayra, Eira barbara, was described in 1758 and has had a stable taxonomic history at the species level. However, below the species level, 16 subspecies have been named, with from two to seven subspecies recognized as valid by different authors. None of the subspecies were, however, described within a clear conceptual framework. Using the modern concept of a subspecies, I analyzed subspecies of E. barbara recognized by recent authors. I gathered morphometric data from 155 specimens in mammal collections, georeferenced each specimen, and recorded membership to subspecies assigned by different references and by its location. I gathered climate and geographic data for each location. I analyzed data using Principal Components Analysis (PCA) and analysis of variance (ANOVA). Specimens exhibited sexual dimorphism in size but not in skull shape. I used regression analysis to test for associations between skull shape and size and climate data. Geographic analyses documented that subspecies are not allopatric, violating one of the main properties of the subspecies concept. ANOVA showed significant differences in skull morphology between some pairs of recognized subspecies but not others. However, none of the subspecies segregated in the PCA. Thus, the recognized subspecies could not be diagnosed from morphological data, violating another property of the subspecies concept. Size varied greatly between the sexes using different schemes for recognized subspecies. Climate variables explained between 4% and 6% of size variation for males and females. Skull shape proved not to be geographically variable.

scholarly journals Geographic variation in the skull morphology of the lesser grison (Galictis cuja: Carnivora, Mustelidae) from two Brazilian ecoregions

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9388
Author(s):  
Raissa Prior Migliorini ◽  
Rodrigo Fornel ◽  
Carlos Benhur Kasper
Keyword(s):  
Atlantic Forest ◽  
Size Variation ◽  
Neotropical Region ◽  
Shape Variation ◽  
Skull Morphology ◽  
Geometric Morphometric ◽  
Morphological Variations ◽  
Skull Shape ◽  
Temperature And Precipitation ◽  
Forest Region

Background The lesser grison (Galictis cuja) is one of the least known carnivores in the Neotropical region. Its wide geographical occurrence and range of habitats could lead to morphological variations along its distribution. So, this study aimed to investigate the variation in skull shape and size of this species, by testing the existence of ecotypes adapted to their respective environments (Uruguayan savanna and Atlantic Forest), as well as its relationship with selected abiotic variables. Methods The skulls of 52 museum specimens were photographed in the ventral, dorsal, and lateral views, and were analyzed using geometric morphometric techniques. Results We found sexual size dimorphism, with males being larger than females. The shape variation between sexes, as well as between ecoregions, is mostly explained by the effect of allometry. The specimens from Uruguayan savanna are larger than the ones from the Atlantic Forest. Size variation was also significantly correlated to latitude, temperature and precipitation patterns. No correlation between skull shape with geographical distance was detected. Discussion Morphometric measurements and diet data of lesser grison in regions from higher latitudes than our sampling show a tendency to heavier individuals, and the consumption of bigger prey compared to Uruguayan savanna. The results indicated the smaller specimens associated to low variability in annual temperature, congruent to Atlantic Forest region. An explanation for observed variation may be related to the “resource rule” but, due the minimal natural history information regards this species, we can just speculate about this.

scholarly journals New specimen of <i>Cacops woehri</i> indicates differences in the ontogenetic trajectories among cacopine dissorophids

Fossil Record ◽  
2015 ◽  
Vol 18 (1) ◽  
pp. 73-80 ◽  
Author(s):  
N. B. Fröbisch ◽  
A. Brar ◽  
R. R. Reisz
Keyword(s):  
Morphological Changes ◽  
Lower Permian ◽  
Ecological Diversity ◽  
Large Specimen ◽  
Skull Morphology ◽  
Skull Shape ◽  
Ontogenetic Trajectories ◽  
Ontogenetic Trajectory ◽  
Taxic Diversity

Abstract. The Lower Permian Dolese locality has produced numerous exquisitely preserved tetrapod fossils representing members of a lower Permian upland fauna. Therein, at least nine taxa of the clade Dissorophoidea, ranging in size from the large predaceous trematopid Acheloma to the miniaturized amphibamid Doleserpeton, highlight the great taxic and ecological diversity of this anamniote clade. Here we describe a large specimen of the dissorophid Cacops woehri, which was previously only known from the juvenile or subadult holotype skull. Another member of the genus Cacops present at the Dolese locality, Cacops morrisi, is also represented by specimens spanning juvenile, subadult, and adult stages, allowing for a comparison of morphological changes taking place in the late phases of the ontogenetic trajectory of cacopine dissorophids. The new find shows that, in contrast to C. morrisi and C. aspidephorus, C. woehri only undergoes relatively subtle changes in skull morphology in late ontogeny and retains the overall more gracile morphology into adult stages. This includes retention of the rather shallow skull shape as well as a pattern of sculpturing consisting of elongate ridges and grooves and a large occipital flange. This suggests somewhat different functional demands in C. woehri than in other known species of Cacops, possibly associated with a different ecology paralleling the great taxic diversity of dissorophoids at the Dolese locality.

scholarly journals Importance of the postcranial skeleton in eusuchian phylogeny: Reassessing the systematics of allodaposuchid crocodylians

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251900
Author(s):  
Alejandro Blanco
Keyword(s):  
Current Knowledge ◽  
Phylogenetic Signal ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
Postcranial Skeleton ◽  
Skull Morphology ◽  
Taxonomic Descriptions ◽  
The Family ◽  
Phylogenetic Hypotheses ◽  
Internal Relationships

Our current knowledge on the crocodyliform evolution is strongly biased towards the skull morphology, and the postcranial skeleton is usually neglected in many taxonomic descriptions. However, it is logical to expect that it can contribute with its own phylogenetic signal. In this paper, the changes in the tree topology caused by the addition of the postcranial information are analysed for the family Allodaposuchidae, the most representative eusuchians in the latest Cretaceous of Europe. At present, different phylogenetic hypotheses have been proposed for this group without reaching a consensus. The results of this paper evidence a shift in the phylogenetic position when the postcranium is included in the dataset, pointing to a relevant phylogenetic signal in the postcranial elements. Finally, the phylogenetic relationships of allodaposuchids within Eusuchia are reassessed; and the internal relationships within Allodaposuchidae are also reconsidered after an exhaustive revision of the morphological data. New and improved diagnoses for each species are here provided.

scholarly journals Taxonomy of the genus Commelina Plum. ex L. (Commelinaceae) in Nepal

2010 ◽  
Vol 6 ◽  
pp. 25-31 ◽  
Author(s):  
Jyoti P Gajurel ◽  
Krishna K Shrestha
Keyword(s):  
Key Words ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Species Level ◽  
Morphological Data ◽  
Plant Science ◽  
The World ◽  
Voucher Specimens ◽  
Key Words Anatomy ◽  
Anatomical Characters

About 170 species of Commelina are known from tropical and subtropical regions of the world. Nepal contributes 6 species of Commelina to the world flora. In the present work, taxonomy of all the six species of Commelina reported from Nepal (C. benghalensis, C. caroliniana, C. diffusa, C. maculata, C. paludosa and C. suffruticosa) was studied. Voucher specimens were collected from Central and Eastern Nepal, covering 14 districts. Morphological characters were studied from these collections. Palynological and anatomical characters were also used to see if they are taxonomically important to delimit the taxa within Commelina. Morphological characters seemed promising to delimit the taxa within Commelina. The key identifying characters at species level are modification in root, form of spathe, structure of leaves and seeds, shape of stomata and pollen. Palynological and anatomical characters were also useful, to some extent, in separating some species, but were not significant as compared to morphological data. Some specimens, close to C. benghalensis and C. caroliniana, showed very different characters. Thus further study is needed to confirm their taxonomic status. Key-words: anatomy; flora; morphological characters; palynology; voucher specimens.DOI: 10.3126/botor.v6i0.2907 Botanica Orientalis - Journal of Plant Science (2009) 6: 25-31

Geographic variation in body size of American mink ( Mustela vison ) / Variation géographique de la taille du corps chez le vison d'Amérique ( Mustela vison )

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Richard T. Stevens ◽  
Michael L. Kennedy
Keyword(s):  
Body Size ◽  
American Mink ◽  
Size Variation ◽  
Mustela Vison ◽  
Morphological Characters ◽  
Geographic Proximity ◽  
Multivariate Statistical ◽  
Components Analysis ◽  
Individual Variables ◽  
Variation Géographique

AbstractSpatial variation in 26 morphological characters of American mink ( Mustela vison ) from 35 localities in North America was investigated using univariate and multivariate statistical analyses. Localities were chosen based on watersheds, and it was hypothesized that high levels of gene flow in minks would prevent partitioning of body size variation within watersheds. All 26 characters in males and 25 of 26 in females exhibited significant interlocality variation. The patterns of variation in body size resulting from principal components analysis indicated that, for both sexes, minks were largest in Alaska, Manitoba, and Alberta; smallest minks were found in Florida and Quebec. There did not appear to be a relationship between body size and geographic proximity. Environmental factors collectively were found to be related to body size, although individual variables were not typically significant. Of 16 environmental variables examined, only longitude was correlated with body size in both sexes, with largest minks in the west and smallest in the east. Latitude was also correlated with body size in females. It was concluded that variation in body size of mink was likely the result of more than one factor that includes both biotic and abiotic features.

Ostracodes as Hydrologic Indicators in Springs, Streams and Wetlands: A Tool for Environmental and Paleoenvironmental Assessment

2003 ◽  
Vol 9 ◽  
pp. 203-222 ◽  
Author(s):  
Alison J. Smith ◽  
Jesse W. Davis ◽  
Donald F. Palmer ◽  
Richard M. Forester ◽  
B. Brandon Curry
Keyword(s):  
Ionic Composition ◽  
The United States ◽  
Ionic Concentration ◽  
Climate Data ◽  
Large Database ◽  
Chemical Parameters ◽  
Hydrologic Indicators ◽  
Components Analysis ◽  
Physical And Chemical ◽  
Total Ionic Concentration

Although the majority of publications on extant nonmarine ostracode species in North America are concerned with lacustrine settings, many species that are potentially valuable as indicators of water quality changes live in non-lacustrine settings. Ostracode distributions in 157 springs, wetlands and streams in the United States are examined here in order to assess 1) species richness, 2) association with physical and chemical parameters of their habitats and 3) the presence of potentially useful biomonitors and environmental sentinels. The 157 non-lacustrine sites are a subset of a large database (North American Non-marine Ostracode Database: NANODe version 1) consisting of 611 mostly lacustrine sites with ostracode species, presence-absence data, hydrochemistry and climate data (Forester et al., in review). Of the 89 species represented in NANODe version 1, 51 species are found in springs, 59 species are found in wetlands and only 15 species are found in streams. Many species are found in at least two of these habitats and some in all three. Principal Components Analysis of these 157 sites indicates that 71% of the variance is explained by salinity (total ionic concentration), alkalinity and temperature, a result consistent with previously published analyses of natural water. Cluster analysis shows that spring species are most strongly tied to temperature, whereas wetlands and streams are most strongly tied to ionic composition. Three species are found to be potentially valuable biomonitors: Cavernocypris wardi in springs, Fabaeformiscandona rawsoni in wetlands and Physocypria globula in streams.

An enigma no more: an integrated taxonomic revision of Aenigmetopia Malloch reveals novel phylogenetic placement and four new species (Diptera : Sarcophagidae : Miltogramminae)

2020 ◽  
Author(s):  
Nikolas P. Johnston ◽  
James F. Wallman ◽  
Krzysztof Szpila ◽  
Thomas Pape
Keyword(s):  
New Species ◽  
Taxonomic Revision ◽  
Single Species ◽  
Species Level ◽  
Morphological Data ◽  
Morphological Evidence ◽  
Phylogenetic Placement ◽  
Molecular Phylogenetic ◽  
First Time ◽  
Flesh Flies

Aenigmetopia Malloch is the only endemic genus of miltogrammine flesh flies (Diptera:Sarcophagidae) in Australia and, until now it has been known from a single species, A. fergusoni Malloch. This study constitutes the first comprehensive taxonomic revision of Aenigmetopia. Four new species, Aenigmetopia amissa, sp. nov., A. corona, sp. nov., A. kryptos, sp. nov. and A. pagoni, sp. nov., are described through the integration of molecular and morphological data and characters for genus- and species-level diagnoses are given. Aenigmetopia is included in a molecular phylogenetic analysis for the first time and the genus emerges as the sister taxon to Metopia Meigen, in agreement with morphological evidence.

Constraint and adaptation in the evolution of carnivoran skull shape

Paleobiology ◽  
2011 ◽  
Vol 37 (3) ◽  
pp. 490-518 ◽  
Author(s):  
Borja Figueirido ◽  
Norman MacLeod ◽  
Jonathan Krieger ◽  
Miquel De Renzi ◽  
Juan Antonio Pérez-Claros ◽  
...  
Keyword(s):  
Morphological Plasticity ◽  
Shape Space ◽  
Cranial Morphology ◽  
Skull Morphology ◽  
Skull Shape ◽  
Olfactory Sense ◽  
History Of ◽  
Proximate Source ◽  
Brain Processing ◽  
Iterative Evolution

The evolutionary history of the Order Carnivora is marked by episodes of iterative evolution. Although this pattern is widely reported in different carnivoran families, the mechanisms driving the evolution of carnivoran skull morphology remain largely unexplored. In this study we use coordinate-point extended eigenshape analysis (CP-EES) to summarize aspects of skull shape in large fissiped carnivores. Results of these comparisons enable the evaluation of the role of different factors constraining the evolution of carnivoran skull design. Empirical morphospaces derived from mandible anatomy show that all hypercarnivores (i.e., those species with a diet that consists almost entirely of vertebrate flesh) share a set of traits involved in a functional compromise between bite force and gape angle, which is reflected in a strong pattern of morphological convergence. Although the paths followed by different taxa to reach this “hypercarnivore shape-space” differ because of phylogenetic constraints, the morphological signature of hypercarnivory in the mandible is remarkably narrow and well constrained. In contrast, CP-EES of cranial morphology does not reveal a similar pattern of shape convergence among hypercarnivores. This suggests a lesser degree of morphological plasticity in the cranium compared to the mandible, which probably results from a compromise between different functional demands in the cranium (e.g., feeding, vision, olfactory sense, and brain processing) whereas the mandible is only involved in food acquisition and processing. Combined analysis of theoretical and empirical morphospaces for these skull data also show the lower anatomical disparity of felids and hyaenids compared to canids and ursids. This indicates that increasing specialization within the hypercarnivorous niche may constrain subsequent morphological and ecological flexibility. During the Cenozoic, similar skull traits appeared in different carnivoran lineages, generated by similar selection pressures (e.g., toward hypercarnivory) and shared developmental pathways. These pathways were likely the proximate source of constraints on the degree of variation associated with carnivoran skull evolution and on its direction.

Evaluating the Taxonomic Status of the Globally Rare Carex roanensis and Allied Species Using Morphology and Amplified Fragment Length Polymorphisms

2008 ◽  
Vol 33 (3) ◽  
pp. 525-535 ◽  
Author(s):  
Tyler W. Smith ◽  
Marcia J. Waterway
Keyword(s):  
Fragment Length ◽  
Taxonomic Status ◽  
Principal Coordinate Analysis ◽  
Species Level ◽  
Morphological Data ◽  
Aflp Data ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
The Common ◽  
Geographic Regions

We used a combination of amplified fragment length polymorphisms (AFLP) and morphological data from 272 individuals from 59 populations to investigate the species-level taxonomy of Carex roanensis and allied species. There were two taxonomic problems in this group: identifying the appropriate taxonomic status for Carex roanensis, and clarifying the distinctions (if any) between C. virescens and C. swanii. Principal coordinate analysis of the morphological data suggested four entities corresponding to C. aestivalis, C. roanensis, C. swanii, and C. virescens, but clear discrimination was not possible. In contrast, the AFLP data showed marked discontinuities among these four species, placing even morphological intermediates into one of four groups. Analysis of molecular variance revealed significant population differentiation within each species, but only C. virescens had any detectable differentiation between geographic regions. This study confirms the species-level distinction between the common and widespread taxa C. swanii and C. virescens, as well as that of the globally rare Appalachian endemic C. roanensis.

Money, Morphology and Molecules. Some comments on Wortley, Bennett and Scotland (2002), Taxonomy and phylogeny reconstruction: two distinct research agendas in systematics. (see p. 335 of this issue)

2002 ◽  
Vol 59 (3) ◽  
pp. 451-457 ◽  
Author(s):  
P. F. STEVENS
Keyword(s):  
Molecular Systematics ◽  
Large Scale ◽  
Species Level ◽  
Molecular Techniques ◽  
Morphological Data ◽  
Phylogeny Reconstruction ◽  
Reasonable Time ◽  
The Past ◽  
Short Time ◽  
Made In

The state of systematics, for convenience here divided into taxonomy (the delimitation, description and inventory of species) and phylogeny reconstruction, is evaluated. Molecular systematics may seem overemphasized, but the resulting gains made in our understanding of relationships in a relatively short time are very considerable. Although morphological data currently play only a limited role in detecting large-scale phylogenetic pattern, the analysis by Wortley et al. of the role morphology has played in the past is not easily interpreted. At species level, it is unclear what effect molecular techniques will have on our understanding of species limits, but it is likely to be considerable. Although taxonomy is both essential and underfunded, there seems little point in asking for more money until we can justify the limits of the species we describe more clearly and until we have cleared up the impediments that so much slow the practice of taxonomy. Business cannot remain as usual if any of the grand inventory projects we have started are to be finished within a reasonable time, or even to be of much use when they are.

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