scholarly journals Biogeographic variation in skull morphology across the Kra Isthmus in dusky leaf monkeys

2018 ◽  
Vol 56 (4) ◽  
pp. 599-610 ◽  
Author(s):  
Tsuyoshi Ito ◽  
Daisuke Koyabu
Keyword(s):  
Skull Morphology ◽  
Leaf Monkeys

scholarly journals The isotopic niche of Atlantic, biting marine mammals and its relationship to skull morphology and body size

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Massimiliano Drago ◽  
Marco Signaroli ◽  
Meica Valdivia ◽  
Enrique M. González ◽  
Asunción Borrell ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Ocean ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Trophic Position ◽  
Sympatric Species ◽  
Isotopic Niche ◽  
Apex Predators ◽  
Skull Morphology ◽  
Ecosystem Based Fisheries Management

AbstractUnderstanding the trophic niches of marine apex predators is necessary to understand interactions between species and to achieve sustainable, ecosystem-based fisheries management. Here, we review the stable carbon and nitrogen isotope ratios for biting marine mammals inhabiting the Atlantic Ocean to test the hypothesis that the relative position of each species within the isospace is rather invariant and that common and predictable patterns of resource partitioning exists because of constrains imposed by body size and skull morphology. Furthermore, we analyze in detail two species-rich communities to test the hypotheses that marine mammals are gape limited and that trophic position increases with gape size. The isotopic niches of species were highly consistent across regions and the topology of the community within the isospace was well conserved across the Atlantic Ocean. Furthermore, pinnipeds exhibited a much lower diversity of isotopic niches than odontocetes. Results also revealed body size as a poor predictor of the isotopic niche, a modest role of skull morphology in determining it, no evidence of gape limitation and little overlap in the isotopic niche of sympatric species. The overall evidence suggests limited trophic flexibility for most species and low ecological redundancy, which should be considered for ecosystem-based fisheries management.

All-Trans Retinoic Acid-Induced Craniofacial Malformation Model: A Prenatal and Postnatal Morphological Analysis

2017 ◽  
Vol 54 (4) ◽  
pp. 391-399 ◽  
Author(s):  
Weicai Wang ◽  
Yutao Jian ◽  
Bin Cai ◽  
Miao Wang ◽  
Mu Chen ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Morphological Analysis ◽  
Bone Development ◽  
Skull Morphology ◽  
Craniofacial Malformations ◽  
Mandibular Incisor ◽  
Craniofacial Bone ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Age Dependent

Objective To characterize the prenatal and postnatal craniofacial bone development in mouse model of all-trans retinoic acid (ATRA) exposure at different ages by a quantitative and morphological analysis of skull morphology. Methods Pregnant mice were exposed to ATRA at embryonic day 10 (E10) and 13 (E13) by oral gavage. Skulls of mice embryos at E19.5 and adult mice at postnatal day 35 (P35) were collected for high-resolution microcomputed tomography (microCT) imaging scanning and section HE staining. Reconstruction and measurement of mouse skulls were performed for prenatal and postnatal analysis of the control and ATRA-exposed mice. Results Craniofacial malformations in mouse models caused by ATRA exposure were age dependent. ATRA exposure at E10 induced cleft palate in 81.8% of the fetuses, whereas the palatine bone of E13-exposed mice was intact. Inhibitions of maxilla and mandible development with craniofacial asymmetry induced were observed at E19.5 and P35. Compared with control and E13-exposed mice, the palatine bones of E10-exposed mice were not elevated and were smaller in dimension. Some E10-exposed mice exhibited other craniofacial abnormalities, including premature fusion of mandibular symphysis with a missing mandibular incisor and a smaller mandible. Severe deviated snouts and amorphous craniofacial suture were detected in E13-exposed mice at P35. Conclusion These morphological variations in E10- and E13-exposed mice suggested that ATRA was teratogenic in craniofacial bone development in mice and the effect was age dependent.

Taxonomy and distribution of the Brazilian species of Thylamys (Didelphimorphia: Didelphidae) / La taxonomie et la distribution des espèces brésiliennes du genre Thylamys (Didelphimorphia: Didelphidae)

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Ana Paula Carmignotto ◽  
Talitha Monfort
Keyword(s):  
Natural History ◽  
Geographic Distribution ◽  
Taxonomic Status ◽  
Skull Morphology ◽  
Geographic Variations ◽  
Qualitative And Quantitative ◽  
Brazilian Species ◽  
New Information ◽  
Capture Method ◽  
Scientific Collections

AbstractThe recent increase in mammal inventories and the widespread use of pitfall traps as a major capture method in Brazil have increased the number of non-volant small mammal specimens in scientific collections, providing new information on natural history, geographical range, and taxonomic status of many marsupials and rodents. To date, however, little is known about the Brazilian species of the marsupial genus Thylamys : the number of species in the country is disputed, as are their names and geographic distribution. Thus, the aim of this study was to define the Brazilian species of the genus, delimiting their taxonomic status and distributional range. We provide qualitative and quantitative data on external and skull morphology for specimens housed in scientific collections. A study of the material available allowed us to recognize the occurrence of three species in Brazil: Thylamys karimii (Petter, 1968), T. macrurus (Olfers, 1818) and T. velutinus (Wagner, 1842). For each of these we provide redescriptions, a discussion of local and geographic variations, geographic distribution, taxonomy, age class differentiation, sexual dimorphism, and natural history.

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.

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