Allometry and morphological integration in the skull of Tupinambis merianae (Lacertilia: Teiidae)

1997 ◽  
Vol 18 (4) ◽  
pp. 397-405 ◽  
Author(s):  
Leandro R. Monteiro ◽  
Augusto S. Abe
Keyword(s):  
Anterior Extremity ◽  
Shape Change ◽  
Morphological Integration ◽  
Growth Patterns ◽  
Ontogenetic Variation ◽  
Temporal Region ◽  
Geometric Morphometric ◽  
Adductor Muscles ◽  
Tupinambis Merianae ◽  
Cranial Kinesis

AbstractThe morphogenetic processes acting in the skull of the lizard Tupinambis merianae were investigated by geometric morphometric techniques. The observed ontogenetic shape change involved a widening of the anterior extremity, stretching and narrowing of the midface, narrowing of the braincase, orbital reduction and elongation of the temporal region (origin of jaw adductor muscles). This change occurred mostly in a localized way in certain cranial regions. The major components identified were: rostrum, midface, dermal elements of braincase (functionally influenced) and endochondral elements of braincase (embryologically influenced). The growth patterns lead to an increased robustness of the skull (particularly the anterior extremity) and a reduction of cranial kinesis. These changes, together with the ontogenetic variation in dentition aid in the ontogenetic variation observed in the diet of these animals, which shift from carnivory to omnivory.

scholarly journals Soft tissue facial changes among adult females during alignment stage of orthodontic treatment: a 3D geometric morphometric study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Si Yu Hou ◽  
Wenwen Zhou ◽  
Hongwei Dai ◽  
Hai Ming Wong ◽  
Yi Feng Wen ◽  
...  
Keyword(s):  
Orthodontic Treatment ◽  
Shape Change ◽  
Morphometric Study ◽  
Temporal Region ◽  
Facial Morphology ◽  
Geometric Morphometric ◽  
Adult Females ◽  
Facial Shape ◽  
Facial Changes ◽  
Facial Form

Abstract Background To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment. Methods 43 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment. Results We observed statistically significant changes in facial shape across the three treatment stages (p = 0.0022). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0045) and from T0 to T2 (p = 0.0072). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.32 mm, 0.21 mm, and 1.34 mm, respectively. Changes in mean facial form were not statistically significant (p = 0.1143). No changes in variance of facial shape were observed across treatment stages (p > 0.05). Conclusion Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.

Soft Tissue Facial Changes Among Adult Females Receiving Orthodontic Treatment: A Spatially Dense 3D Geometric Morphometric Study

2020 ◽  
Author(s):  
Si Yu Hou ◽  
Wenwen Zhou ◽  
Hongwei Dai ◽  
Hai Ming Wong ◽  
Yi Feng Wen ◽  
...  
Keyword(s):  
Orthodontic Treatment ◽  
Shape Change ◽  
Morphometric Study ◽  
Temporal Region ◽  
Facial Morphology ◽  
Geometric Morphometric ◽  
Adult Females ◽  
Facial Shape ◽  
Mean And Variance ◽  
Facial Changes

Abstract Background: To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment.Methods: 18 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment.Results: We observed statistically significant changes in facial shape across the three treatment stages (p = 0.003). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0059) and from T0 to T2 (p = 0.0098). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.31 mm, 0.22 mm, and 1.33 mm, respectively. Changes in mean facial shape were not statistically significant (p = 0.103). No changes in variance of facial shape were observed across treatment stages (p > 0.05).Conclusion: Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.

scholarly journals Soft tissue facial changes among adult females during the first six months of orthodontic treatment: a spatially dense 3D geometric morphometric study

2020 ◽  
Author(s):  
Si Yu Hou ◽  
Wenwen Zhou ◽  
Hongwei Dai ◽  
Hai Ming Wong ◽  
Yi Feng Wen ◽  
...  
Keyword(s):  
Orthodontic Treatment ◽  
Shape Change ◽  
Morphometric Study ◽  
Temporal Region ◽  
Facial Morphology ◽  
Geometric Morphometric ◽  
Adult Females ◽  
Facial Shape ◽  
Facial Changes ◽  
Facial Form

Abstract Background: To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment.Methods: 18 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment.Results: We observed statistically significant changes in facial shape across the three treatment stages (p = 0.003). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0059) and from T0 to T2 (p = 0.0098). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.31 mm, 0.22 mm, and 1.33 mm, respectively. Changes in mean facial form were not statistically significant (p = 0.103). No changes in variance of facial shape were observed across treatment stages (p > 0.05).Conclusion: Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.

scholarly journals Unravelling the hybrid vigor in domestic equids: the effect of hybridization on bone shape variation and covariation

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Pauline Hanot ◽  
Anthony Herrel ◽  
Claude Guintard ◽  
Raphaël Cornette
Keyword(s):  
First Generation ◽  
Shape Change ◽  
Morphological Integration ◽  
Hybrid Vigor ◽  
F1 Hybrids ◽  
Shape Variation ◽  
Locomotor System ◽  
Domestic Horses ◽  
Functional Mechanisms ◽  
Underlying Processes

Abstract Background Hybridization has been widely practiced in plant and animal breeding as a means to enhance the quality and fitness of the organisms. In domestic equids, this hybrid vigor takes the form of improved physical and physiological characteristics, notably for strength or endurance. Because the offspring of horse and donkey is generally sterile, this widely recognized vigor is expressed in the first generation (F1). However, in the absence of recombination between the two parental genomes, F1 hybrids can be expected to be phenotypically intermediate between their parents which could potentially restrict the possibilities of an increase in overall fitness. In this study, we examine the morphology of the main limb bones of domestic horses, donkeys and their hybrids to investigate the phenotypic impact of hybridization on the locomotor system. We explore bone shape variation and covariation to gain insights into the morphological and functional expressions of the hybrid vigor commonly described in domestic equids. Results Our data reveal the occurrence of transgressive effects on several bones in the F1 generation. The patterns of morphological integration further demonstrate that the developmental processes producing covariation are not disrupted by hybridization, contrary to functional ones. Conclusions These results suggest that an increase in overall fitness could be related to more flexibility in shape change in hybrids, except for the main forelimb long bones of which the morphology is strongly driven by muscle interactions. More broadly, this study illustrates the interest of investigating not only bone shape variation but also underlying processes, in order to contribute to better understanding how developmental and functional mechanisms are affected by hybridization.

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

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.

A geometric morphometric analysis of hominin upper premolars. Shape variation and morphological integration

2011 ◽  
Vol 61 (6) ◽  
pp. 688-702 ◽  
Author(s):  
Aida Gómez-Robles ◽  
María Martinón-Torres ◽  
José María Bermúdez de Castro ◽  
Leyre Prado-Simón ◽  
Juan Luis Arsuaga
Keyword(s):  
Morphometric Analysis ◽  
Morphological Integration ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Geometric Morphometric Analysis

scholarly journals Monogenean anchor morphometry: systematic value, phylogenetic signal, and evolution

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1668 ◽  
Author(s):  
Tsung Fei Khang ◽  
Oi Yoon Michelle Soo ◽  
Wooi Boon Tan ◽  
Lee Hong Susan Lim
Keyword(s):  
Body Size ◽  
Phylogenetic Signal ◽  
R Package ◽  
Copulatory Organ ◽  
Morphological Integration ◽  
28S Rrna ◽  
Morphometric Data ◽  
Geometric Morphometric ◽  
Shape Data ◽  
Shape And Size

Background.Anchors are one of the important attachment appendages for monogenean parasites. Common descent and evolutionary processes have left their mark on anchor morphometry, in the form of patterns of shape and size variation useful for systematic and evolutionary studies. When combined with morphological and molecular data, analysis of anchor morphometry can potentially answer a wide range of biological questions.Materials and Methods.We used data from anchor morphometry, body size and morphology of 13Ligophorus(Monogenea: Ancyrocephalidae) species infecting two marine mugilid (Teleostei: Mugilidae) fish hosts:Moolgarda buchanani(Bleeker) andLiza subviridis(Valenciennes) from Malaysia. Anchor shape and size data (n= 530) were generated using methods of geometric morphometrics. We used 28S rRNA, 18S rRNA, and ITS1 sequence data to infer a maximum likelihood phylogeny. We discriminated species using principal component and cluster analysis of shape data. Adams’sKmultwas used to detect phylogenetic signal in anchor shape. Phylogeny-correlated size and shape changes were investigated using continuous character mapping and directional statistics, respectively. We assessed morphological constraints in anchor morphometry using phylogenetic regression of anchor shape against body size and anchor size. Anchor morphological integration was studied using partial least squares method. The association between copulatory organ morphology and anchor shape and size in phylomorphospace was used to test the Rohde-Hobbs hypothesis. We created monogeneaGM, a new R package that integrates analyses of monogenean anchor geometric morphometric data with morphological and phylogenetic data.Results.We discriminated 12 of the 13Ligophorusspecies using anchor shape data. Significant phylogenetic signal was detected in anchor shape. Thus, we discovered new morphological characters based on anchor shaft shape, the length between the inner root point and the outer root point, and the length between the inner root point and the dent point. The species onM. buchananievolved larger, more robust anchors; those onL. subviridisevolved smaller, more delicate anchors. Anchor shape and size were significantly correlated, suggesting constraints in anchor evolution. Tight integration between the root and the point compartments within anchors confirms the anchor as a single, fully integrated module. The correlation between male copulatory organ morphology and size with anchor shape was consistent with predictions from the Rohde-Hobbs hypothesis.Conclusions.Monogenean anchors are tightly integrated structures, and their shape variation correlates strongly with phylogeny, thus underscoring their value for systematic and evolutionary biology studies. Our MonogeneaGM R package provides tools for researchers to mine biological insights from geometric morphometric data of speciose monogenean genera.

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