A non-invasive geometric morphometrics method for exploring variation in dorsal head shape in urodeles: sexual dimorphism and geographic variation inSalamandra salamandra

2017 ◽  
Vol 278 (4) ◽  
pp. 475-485 ◽  
Author(s):  
Lucía Alarcón-Ríos ◽  
Guillermo Velo-Antón ◽  
Antigoni Kaliontzopoulou
Keyword(s):  
Sexual Dimorphism ◽  
Geometric Morphometrics ◽  
Geographic Variation ◽  
Head Shape ◽  
Non Invasive

scholarly journals Size and shape variability in the skull of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from two geographic areas in Brazil

2008 ◽  
Vol 68 (3) ◽  
pp. 623-631 ◽  
Author(s):  
R. Bornholdt ◽  
LR. Oliveira ◽  
ME. Fabián
Keyword(s):  
Sexual Dimorphism ◽  
Geometric Morphometrics ◽  
Geographic Variation ◽  
Ecological Factors ◽  
Lateral View ◽  
Centroid Size ◽  
Skull Shape ◽  
Size And Shape ◽  
The Brain ◽  
South Brazil

We present a quantitative analysis of sexual dimorphism and geographic variation in the skull of Myotis nigricans (Schinz, 1821) assessed by geometric morphometrics. Differences in size and shape of skulls were investigated using 30 landmarks plotted on two-dimensional images of lateral and ventral views. Results of geometric morphometrics revealed sexual dimorphism in the centroid size of the skull in both views. Females were larger than males. Nevertheless, there was no sexual dimorphism in skull shape of M. nigricans. Geographic variation was detected in size and shape of the skull. South Brazilian specimens were significantly larger than Ceará specimens only in the lateral view. Differences in skull shape were statistically significant in both views: specimens from South Brazil were brevirostri and presented a more expanded skull in the posterior region while Ceará specimens were longirostri and do not present any expansion in the brain case. Ecological factors for these phenomena are discussed in the text.

scholarly journals New Geometric Morphometric Insights in Digital Taphonomy: Analyses into the Sexual Dimorphism of Felids through Their Tooth Pits

2021 ◽  
Vol 11 (17) ◽  
pp. 7848
Author(s):  
Darío Herranz-Rodrigo ◽  
Silvia J. Tardáguila-Giacomozzi ◽  
Lloyd A. Courtenay ◽  
Juan-José Rodríguez-Alba ◽  
Antonio Garrucho ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Geometric Morphometrics ◽  
Applied Statistics ◽  
Panthera Tigris ◽  
Panthera Pardus ◽  
Geometric Morphometric ◽  
Male And Female ◽  
New Horizons ◽  
Carnivore Species ◽  
Felid Species

Recent studies using geometric morphometrics for taphonomy have yielded interesting results, opening new horizons of research in both archaeological and paleontological sites. Here we present the analysis of tooth pits left by male and female individuals of two different carnivore species (Panthera tigris and Panthera pardus) in order to see if sexual dimorphism influences the morphology of tooth pit marks. In the process, 3D-scanning and applied statistics were used. Based on samples derived from two individuals of different sexes, the present results indicate sexual dimorphism in these felid species to not be a conditioning factor of tooth pit morphology.

scholarly journals Morphology of the franciscana (Pontoporia blainvillei) off southeastern Brazil: sexual dimorphism, growth and geographic variation

2002 ◽  
Vol 1 (1) ◽  
Author(s):  
R. M. A. Ramos ◽  
A. P. M. Di Beneditto ◽  
S. Siciliano ◽  
M. C. O. Santos ◽  
A. N. Zerbini ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Geographic Variation ◽  
Southeastern Brazil ◽  
Pontoporia Blainvillei

A Geometric Morphometric Assessment of Hand Shape and Comparison to the 2D:4D Digit Ratio as a Marker of Sexual Dimorphism

2013 ◽  
Vol 16 (2) ◽  
pp. 590-600 ◽  
Author(s):  
Paul G. Sanfilippo ◽  
Alex W. Hewitt ◽  
Jenny A. Mountain ◽  
David A. Mackey
Keyword(s):  
Sexual Dimorphism ◽  
Geometric Morphometrics ◽  
Shape Analysis ◽  
Twin Studies ◽  
Analytical Techniques ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Hand Shape ◽  
Physical Traits ◽  
Biological Shape

Twin studies are extremely useful for investigating hypotheses of genetic influence on a range of behavioral and physical traits in humans. Studies of physical traits, however, are usually limited to size-related biological characteristics because it is inherently difficult to quantify the morphological counterpart – shape. In recent years, the development of geometry-preserving analytical techniques built upon multivariate statistical methodologies has produced a new discipline in biological shape analysis known as geometric morphometrics. In this study of hand shape analysis, we introduce the reader already familiar with the field of twin research to the potential utility of geometric morphometrics and demonstrate the cross-discipline applicability of methods. We also investigate and compare the efficacy of the 2D:4D ratio, a commonly used marker of sexual dimorphism, to the fully multivariate approach of shape analysis in discriminating between male and female sex. Studies of biological shape variation utilizing geometric morphometric techniques may be completed with software freely available on the Internet and time invested to master the small learning curve in concepts and theory.

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