scholarly journals Contributions to the functional morphology of caudate skulls: kinetic and akinetic forms

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2392 ◽  
Author(s):  
Nikolay Natchev ◽  
Stephan Handschuh ◽  
Simeon Lukanov ◽  
Nikolay Tzankov ◽  
Borislav Naumov ◽  
...  
Keyword(s):  
Functional Morphology ◽  
Similar Degree ◽  
Specific Combination ◽  
Skull Roof ◽  
Fire Salamander ◽  
The Common ◽  
Flexible Connections ◽  
Salamandra Salamandra

A strongly ossified and rigid skull roof, which prevents parietal kinesis, has been reported for the adults of all amphibian clades. Our μ-CT investigations revealed that the Buresch’s newt (Triturus ivanbureschi) possess a peculiar cranial construction. In addition to the typical amphibian pleurokinetic articulation between skull roof and palatoquadrate associated structures, we found flexible connections between nasals and frontals (prokinesis), vomer and parasphenoid (palatokinesis), and between frontals and parietals (mesokinesis). This is the first description of mesokinesis in urodelans. The construction of the skull in the Buresch’s newts also indicates the presence of an articulation between parietals and the exocipitals, discussed as a possible kind of metakinesis. The specific combination of pleuro-, pro-, meso-, palato-, and metakinetic skull articulations indicate to a new kind of kinetic systems unknown for urodelans to this date. We discuss the possible neotenic origin of the skull kinesis and pose the hypothesis that the kinesis inT. ivanbureschiincreases the efficiency of fast jaw closure. For that, we compared the construction of the skull inT. ivanbureschito the akinetic skull of the Common fire salamanderSalamandra salamandra. We hypothesize that the design of the skull in the purely terrestrial living salamander shows a similar degree of intracranial mobility. However, this mobility is permitted by elasticity of some bones and not by true articulation between them. We comment on the possible relation between the skull construction and the form of prey shaking mechanism that the species apply to immobilize their victims.

scholarly journals Cranial integration in the fire salamander, Salamandra salamandra (Caudata: Salamandridae)

2020 ◽  
Vol 130 (1) ◽  
pp. 178-194 ◽  
Author(s):  
Margot Bon ◽  
Carla Bardua ◽  
Anjali Goswami ◽  
Anne-Claire Fabre
Keyword(s):  
Influencing Factors ◽  
Significant Relationship ◽  
High Dimensional ◽  
Phenotypic Integration ◽  
Geometric Morphometric ◽  
Complex Interactions ◽  
Fire Salamander ◽  
Salamandra Salamandra ◽  
Static Level ◽  
Cranial Shape

Abstract Phenotypic integration and modularity are concepts that represent the pattern of connectivity of morphological structures within an organism. Integration describes the coordinated variation of traits, and analyses of these relationships among traits often reveals the presence of modules, sets of traits that are highly integrated but relatively independent of other traits. Phenotypic integration and modularity have been studied at both the evolutionary and static level across a variety of clades, although most studies thus far are focused on amniotes, and especially mammals. Using a high-dimensional geometric morphometric approach, we investigated the pattern of cranial integration and modularity of the Italian fire salamander (Salamandra salamandra giglioli). We recovered a highly modular pattern, but this pattern did not support either entirely developmental or functional hypotheses of cranial organisation, possibly reflecting complex interactions amongst multiple influencing factors. We found that size had no significant effect on cranial shape, and that morphological variance of individual modules had no significant relationship with degree of within-module integration. The pattern of cranial integration in the fire salamander is similar to that previously recovered for caecilians, with highly integrated jaw suspensorium and occipital regions, suggesting possible conservation of patterns across lissamphibians.

scholarly journals Flexibility of Heterocercal Tails: What Can the Functional Morphology of Shark Tails Tell Us about Ichthyosaur Swimming?

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
S B Crofts ◽  
R Shehata ◽  
B E Flammang
Keyword(s):  
Functional Morphology ◽  
Flexural Stiffness ◽  
Cross Sectional ◽  
Text Book ◽  
Structural Differences ◽  
Thresher Shark ◽  
Cross Sectional Profile ◽  
The Common ◽  
Sectional Profile ◽  
Tail Function

Synopsis The similarities between ichthyosaurs and sharks are a text-book example of convergence, and similarities in tail morphology have led many to theorize that they had similar swimming styles. The variation of ichthyosaur tail shapes is encompassed within the diversity of shark families. In particular early ichthyosaurs have asymmetrical tails like the heterocercal tails of carcharhinid sharks, while later occurring ichthyosaurs have lunate tails similar to those of lamnid sharks. Because it is not possible to measure ichthyosaur tail function, the goal of this study is to measure and compare the flexibility and stiffness of lunate and heterocercal shark tails, and to measure skeletal and connective tissue features that may affect tail flexibility. We measured flexibility in 10 species and focused on five species in particular, for dissection: one pelagic and one bottom-associated individual from each order, plus the common thresher shark (Alopias vulpinus), a tail-slapping specialist. As expected, lunate tails were overall less flexible than heterocercal tails and had greater flexural stiffness. Our results suggest that the cross-sectional profile of the skeletally supported dorsal lobe dictates flexural stiffness, but that changing tissue composition dictates flexural stiffness in the ventral lobe. We also found structural differences that may enable the tail slapping behavior of the common thresher shark. Finally, we discuss how our morphological measurements compare to ichthyosaur measurements from the literature; noting that similarities in functional morphology suggest sharks may be a good analog for understanding ichthyosaur swimming biomechanics.

scholarly journals Ultrasonography: a method used for pregnancy imaging of the fire salamander (Salamandra salamandra)

2016 ◽  
Vol 19 (4) ◽  
pp. 715-722
Author(s):  
A. Najbar ◽  
Z. Kiełbowicz ◽  
J. Szymczak ◽  
M. Ogielska
Keyword(s):  
Veterinary Medicine ◽  
Ultrasound Imaging ◽  
Length Measurements ◽  
Fire Salamander ◽  
Minimum Number ◽  
Salamandra Salamandra ◽  
Gravid Females ◽  
Lower Silesia ◽  
In Pregnancy

Abstract Ultrasound imaging has more frequently been used in veterinary medicine of amphibians and reptiles. In this study, we have verified the usefulness of ultrasound imaging in pregnancy determination of the fire salamander Salamandra salamandra. We have also undertaken to estimate the number of larvae and their developmental stage directly in the oviducts. Three gravid females from Lower Silesia (southern Poland) were examined. Due to the small size of the scanned animals, and the particular arrangement of embryos in the oviducts and ultrasound beams dispersal, the method proved to be inaccurate. Therefore, the minimum number of well-visualized larvae was determined. The maximum number of larvae was established on the basis of the visible fragments of embryos. After birth, we found that the number of larvae born was included in the „min-max” range in only one case. In the remaining two salamanders the number of larvae was higher than estimated in 3 to 7 individuals. The results showed that ultrasound imaging allows the minimum number of larvae in salamander; oviducts to be specified. However, total length measurements were possible only for single and clearly visible embryos.

scholarly journals No Sexual Dimorphism Detected in Digit Ratios of the Fire Salamander (Salamandra salamandra)

2015 ◽  
Vol 298 (10) ◽  
pp. 1786-1795 ◽  
Author(s):  
Monika Balogová ◽  
Emma Nelson ◽  
Marcel Uhrin ◽  
Mária Figurová ◽  
Valent Ledecký ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Digit Ratios ◽  
Fire Salamander ◽  
Salamandra Salamandra

scholarly journals Rapid Benzylation of Wood Powder without Heating

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1118
Author(s):  
Mitsuru Abe ◽  
Masako Seki ◽  
Tsunehisa Miki ◽  
Masakazu Nishida
Keyword(s):  
Alkaline Treatment ◽  
Thermomechanical Analysis ◽  
Common Method ◽  
Similar Degree ◽  
Hydroxyl Groups ◽  
Wood Powder ◽  
Alkali Pretreatment ◽  
Long Time ◽  
Naoh Solution ◽  
The Common

Converting wood waste into thermoplastic materials is an attractive means of increasing its utilization. A promising method for imparting thermoplasticity to wood is chemical modification, in which the hydroxyl groups in wood are substituted with benzyl groups. In the common method, wood powder is first treated with a highly concentrated aqueous NaOH solution, and then reacted with a benzylation reagent by heating for a long time under stirring. In this study, a 50% aqueous tetra-n-butylphosphonium hydroxide solution was used for the pretreatment of wood powder. This modified alkaline treatment enhanced the efficiency of the subsequent benzylation reaction, which could be conducted without heating over a shorter time. The effects of various conditions on the efficiency of the benzylation reaction were evaluated. Both the alkali pretreatment and the subsequent benzylation required only ~5–10 min of stirring without heating to obtain benzylated wood with a similar degree of benzylation as that achieved by the common method. The chemical structure of the benzylated wood powder was characterized by Fourier-transform infrared and solid-state NMR spectroscopies, and its thermal softening characteristics were evaluated by thermomechanical analysis. Finally, a translucent film could be obtained by hot-pressing the benzylated wood powder.

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