Sieved mass and shape data from simulated fluvial transport of icy clasts in the Titan Tumbler

Abstract The aim of this paper is to present the stages of development of an alluvial cone as an indication of change in natural environment conditions. a detailed research was conducted within the upland regions of Drawsko Lakeland. At the valley mouth of one of the erosional-denudational valleys an alluvial cone in question splays out. The imparity between the capacity of the erosional-denudational valley and the capacity of the alluvial cone indicates that the main stage of erosion had taken place before the cone’s deposition. During the beginning stage the material acquired from the dissection was most likely delivered directly to the channel of Dębnica river and was incorporated in the fluvial transport. The cone was formed during the later stage. The results of the radiocarbon analyses reveal that the formation of the alluvial cone and the valley associated with the cone took place during the Subatlantic. It was also estimated that the cone aggraded with the rate of approximately 3,9 mm per year

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The impact of allometry on vomer shape and its implications for the taxonomy and cranial kinesis of crown-group birds

10.1101/2020.07.02.184101 ◽

2020 ◽

Author(s):

Olivia Plateau ◽

Christian Foth

Keyword(s):

Anterior Part ◽

Correct Identification ◽

Temporal Region ◽

Shape Variation ◽

Crown Group ◽

Multivariate Statistical ◽

Morphological Differences ◽

Cranial Kinesis ◽

The Impact ◽

Shape Data

AbstractCrown birds are subdivided into two main groups, Palaeognathae and Neognathae, that can be distinguished, among others, by the organization of the bones in their pterygoid-palatine complex (PPC). Shape variation to the vomer, which is the most anterior part of the PPC, was recently analysed by Hu et al. (2019) with help of geometric morphometrics to discover morphological differences between palaeognath and neognath birds. Based on this study, the vomer was identified as sufficient to distinguish the two main groups (and even more inclusive neognath groups) and their cranial kinetic system. As there are notable size differences between the skulls of palaeognaths and neognaths, we here investigate the impact of allometry on vomeral shape and its implication for taxonomic classification by re-analysing the data of the previous study. Different types of multivariate statistical analyses reveal that taxonomic identification based on vomeral shape is strongly impaired by allometry, as the error of correct identification is high when shape data is corrected for size. This finding is evident by a great overlap between palaeognath and neognath subclades in morphospace. The correct identification is further influenced by the convergent presence of a flattened vomeral morphotype in multiple neognath subclades. As the evolution of cranial kinesis has been linked to vomeral shape in the original study, the existing correlation between shape and size of the vomer across different bird groups found in the present study questions this conclusion. In fact, cranial kinesis in crown birds results from the loss of the jugal-postorbital bar in the temporal region and ectopterygoid in the PPC and the combination of a mobilized quadrate-zygomatic arch complex and a flexible PPC. Therefore, we can conclude that the vomer itself is not a suitable proxy for exploring the evolution of cranial kinesis in crown birds and their ancestors.

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Wing morphometry as a tool for correct identification of primary and secondary New World screwworm fly

Bulletin of Entomological Research ◽

10.1017/s0007485309006762 ◽

2009 ◽

Vol 100 (1) ◽

pp. 19-26 ◽

Cited By ~ 14

Author(s):

M.L. Lyra ◽

L.M. Hatadani ◽

A.M.L. de Azeredo-Espin ◽

L.B. Klaczko

Keyword(s):

Population Variation ◽

Canonical Variate ◽

Correct Identification ◽

Morphological Marker ◽

Geometric Morphometric ◽

Control Programs ◽

Cochliomyia Macellaria ◽

Males And Females ◽

Cattle Breeders ◽

Shape Data

AbstractCochliomyia hominivoraxandCochliomyia macellariaare endemic Neotropical Calliphoridae species. The former causes severe myiasis in hosts while the latter is Sarcosaprophagous, but commonly found as a second invader in wounds. Due to the morphological similarity between them and the potential losses thatC. hominivoraxrepresents for cattle breeders, the rapid and correct identification of these two species is very important. In addition to a correct identification of these species, a good knowledge ofC. hominivoraxbiology can be helpful for designing control programs. We applied geometric morphometric methods to assess wing differences betweenC. hominivoraxandC. macellariaand conduct a preliminary analysis of wing morphological variation inC. hominivoraxpopulations. Canonical variate analysis, using wing shape data, correctly classified 100% of the individuals analyzed according to sex and species. This result demonstrates that wing morphometry is a simple and reliable method for identifyingC. hominivoraxandC. macellariasamples and can be used to monitorC. hominivorax. Both species show sexual dimorphism, but inC. hominivoraxit is magnified. We suggest that this may reflect different histories of selection pressures operating on males and females. Significant differences in wing size and shape were obtained amongC. hominivoraxpopulations, with little correlation with latitude. This result suggests that wing variation is also a good morphological marker for studying population variation inC. hominivorax.

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