scholarly journals New skull material of Pleistocene dwarf deer from Crete (Greece)

2021 ◽  
Author(s):  
Ann-Marie SCHILLING ◽  
Gertrud E. RÖSSNER
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Skeletal Morphology ◽  
Number Of Species ◽  
Fossil Site ◽  
Respective Species

In the Pleistocene faunas of the island of Crete, Cervidae was one of the most abundant taxa. Respective species vary in body size, including dwarfs, and skeletal morphology; however, the number of species and the identity of the mainland ancestor(s) are still debated. In this paper, we morphologically and morpho­metrically describe and analyze eight skulls of Cretan deer from a so far little known fossil site near Gerani, Rethymnon, Greece. The recorded character suite allows for affiliation to dwarfed Candiacervus Kuss, 1975, Candiacervus ropalophorus de Vos, 1984 and C. reumeri van der Geer, 2018. It comprises previously unknown unique traits, some of them hinting to sexual dimorphism. Comparisons of the Candiacervus skulls presented here with those of cervids belonging to Megalocerotini Brooke, 1828, s.s. and s.l. stress certain similarities; yet more material is needed to reconstruct Candiacervus’ phylo­genetic position. The newly detected craniodental specifics allow for more insights into island adaptation of Candiacervus; at the same time, they blur the morphological heritage of their mainland ancestors.

Sexual dimorphism in human cranial trait scores: Effects of population, age, and body size

2014 ◽  
Vol 154 (2) ◽  
pp. 259-269 ◽  
Author(s):  
Heather M. Garvin ◽  
Sabrina B. Sholts ◽  
Laurel A. Mosca
Keyword(s):  
Body Size ◽  
Sexual Dimorphism

Body size, brain size, and sexual dimorphism in Homo naledi from the Dinaledi Chamber

2017 ◽  
Vol 111 ◽  
pp. 119-138 ◽  
Author(s):  
Heather M. Garvin ◽  
Marina C. Elliott ◽  
Lucas K. Delezene ◽  
John Hawks ◽  
Steven E. Churchill ◽  
...  
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Brain Size

scholarly journals Phenotypic Variation in Skull Size and Shape Between Newfoundland and Mainland Populations of North American Black Bears, Ursus americanus

2003 ◽  
Vol 117 (2) ◽  
pp. 236 ◽  
Author(s):  
John A. Virgl ◽  
Shane P. Mahoney ◽  
Kim Mawhinney
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Ursus Americanus ◽  
Population Variation ◽  
Black Bears ◽  
Selection Pressures ◽  
Skull Shape ◽  
Skull Size ◽  
Environmental Selection ◽  
Gape Size

It is well recognized that differences in environmental selection pressures among populations can generate phenotypic divergence in a suite of morphological characteristics and associated life history traits. Previous analysis of mitochondrial DNA and body size have suggested that Black Bears (Ursus americanus) inhabiting the island of Newfoundland represent a different subspecies or ecotype from mainland populations. Assuming that body size covaries positively with skull size, we predicted that skull size would be greater for bears on the island than the mainland, and the distribution of size-related shape components in multivariate space should show a distinct separation between Newfoundland and mainland populations. Measurements of 1080 specimens from Newfoundland, Alberta, New York, and Quebec did not provide unequivocal support for our prediction that skull size in Newfoundland bears would be larger than bears from the mainland populations. After removing ontogenetic effects of skull size, between-population variation in skull shape was greater in females than males, and the analysis significantly separated Newfoundland bears from mainland populations. Explanations for this pattern are numerous, but currently remain hypothetical. Limited covariation between skull size and body size suggests that genetic traits regulating the size of Black Bear skulls are more heritable (i.e., less influenced by environmental selection pressures) than characteristics affecting body size. We hypothesize that if gape size does not limit prey size in solitary terrestrial carnivores, large degrees of among-population variation in body size should be coupled with little covariation in skull size. In general, sexual dimorphism in skull size and shape was marginal for the phenotypic characters measured in our study. We believe that sexual dimorphism in skull size in Black Bears is primarily driven by intrasexual selection in males for increased gape size display, while similarity in skull shape between sexes is associated with the constraints of a temporally-selective, but similar diet.

Sexual dimorphism in body size and life‐history traits in a population ofTriturus alpestris alpestris

2004 ◽  
Vol 71 (sup2) ◽  
pp. 117-120 ◽  
Author(s):  
Elena Marzona ◽  
Daniele Seglie ◽  
Cristina Giacoma
Keyword(s):  
Life History ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Life History Traits

scholarly journals Body size, female reproduction and sexual dimorphism in the lizard Ameiva ameiva (Teiidae) in a restinga of southeastern Brazil

2008 ◽  
Vol 25 (2) ◽  
pp. 370-372 ◽  
Author(s):  
Carlos Frederico Duarte Rocha
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Clutch Size ◽  
Reproductive Period ◽  
Southeastern Brazil ◽  
Head Width ◽  
Sexually Dimorphic ◽  
Female Reproduction ◽  
Female Body Size ◽  
Reproductive Body

In this study 57 specimens of the lizard Ameiva ameiva (Linnaeus, 1758) collected in the restinga at Barra de Maricá, in the state of Rio de Janeiro, southeastern Brazil, were analyzed to investigate size relations and reproduction (in females) and sexual dimorphism of this population. We answered the following questions: 1) what is the minimum reproductive body size in females? 2) what is the average clutch size and 3) how is clutch size related to body size? 4) Are body and head sizes sexually dimorphic? Mean clutch size was 6.7 ± 2.1 eggs and was positively correlated with female body size. Sexual dimorphism favoring males was found: adult mean snout-vent length was great in males (124.2 ± 17.8 mm) than females (96.5 ± 23.1 mm SVL), and males were larger with respect to head width and length, and body mass. Thus, despite the marked seasonality at Barra de Maricá, A. ameiva has an extended reproductive period. Also, intrasexual selection may have acted on females to produce larger clutches, and on males, favoring larger males.

Estrogen receptor regulation of pulmonary alveolar dimensions: alveolar sexual dimorphism in mice

2006 ◽  
Vol 290 (5) ◽  
pp. L866-L870 ◽  
Author(s):  
Donald Massaro ◽  
Gloria DeCarlo Massaro
Keyword(s):  
Estrogen Receptor ◽  
Sexual Dimorphism ◽  
Surface Area ◽  
Body Mass ◽  
Female Rats ◽  
Female Mice ◽  
Alveolar Surface Area ◽  
Rats And Mice ◽  
Alveolar Surface ◽  
Respective Species

Female rats and mice have smaller and, per body mass (BM), more alveoli and alveolar surface area (Sa) than males of their respective species. This sexual dimorphism becomes apparent about the time of sexual maturity. It is prevented in rats (not tested in mice) by ovariectomy at age 3 wk. In female mice, estrogen receptor (ER)-α and ER-β are required for formation of alveoli of appropriate size and number. We now report the average volume of an alveolus (v̄a) and the number of alveoli per body mass (Na/BM) were not statistically different between ER-α−/− and wild type (wt) males. However, the combination of a larger value for v̄a and a smaller value for Na/BM, though neither parameter achieved a statistically significant intergroup difference, resulted in a statistically significant lower Sa/BM in ER-α−/− males compared with wt males. In ER-β−/− males, v̄a was bigger and Na/BM and Sa/BM were lower compared with wt males. Wt males had larger alveoli and lower Na/BM and Sa/BM than wt females. The wt sexual dimorphism of v̄a, Na/BM, and Sa/BM was absent in ER-α−/− mice. Alveolar size did not differ between ER-β−/− females and males but Na/BM and Sa/BM were greater in ER-β−/− females than in ER-β−/− males. The results in male mice, with prior findings in female mice, 1) demonstrate estrogen receptors have a smaller effect on alveolar dimensions in male than female mice, 2) show ER-α and ER-β are required for the sexual dimorphism of alveolar size, and 3) show ER-α is needed for the sexual dimorphism of body mass-specific alveolar number and surface area.

scholarly journals THE ORIGINS OF SEXUAL DIMORPHISM IN BODY SIZE IN UNGULATES

Evolution ◽  
2002 ◽  
Vol 56 (6) ◽  
pp. 1276-1285 ◽  
Author(s):  
F. J. Pérez-Barbería ◽  
I. J. Gordon ◽  
M. Pagel
Keyword(s):  
Body Size ◽  
Sexual Dimorphism
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