Morphology, morphometry and some aspects of clinical anatomy in the skull and mandible of Sharri sheep

Comparison of Skull Morphometric Characteristics of Simmental and Holstein Cattle Breeds

This study aimed to reveal the morphological characteristics of pure Holstein and Simmental skulls and to obtain reference values for morphometric analysis. Moreover, 54 skulls from 12- to 14-month-old male Holstein (n = 25) and Simmental (n = 29) cattle were collected from Turkey's Southeastern Anatolia Region between 2023 and 2024. Linear measurements indicated that Holsteins had longer skulls compared to Simmentals. Holsteins exhibited significantly higher values for the greatest length of nasals and the shortest skull length. The facial breadth was wider in Holsteins and statistically distinctive between the breeds. Holsteins had a more oval orbital bony roof, while Simmentals exhibited a wider orbital structure. The orbital index was higher in Holsteins, distinguishing between the two breeds. It was observed that Simmental cattle had a wider occipital region. This difference is likely due to the larger lateral appearance of the Simmental skull, which has more body weight and provides a larger surface area for muscle attachment. These differences not only aid in breed identification but also offer insights into the functional adaptations of each breed. Future research should explore the genetic and environmental factors contributing to these morphological traits, further enriching our knowledge of cattle morphology and its implications for breeding and conservation efforts.

Shape variation in cranium, mandible and teeth in selected mouse strains

There are different strains of laboratory mouse used in many different fields. These strains differ anatomically. In order to determine these anatomical differences, shape analysis was conducted according to species. CD-1, C57bl/6 and Balb-c strains were preferred to study these differences. Forty-eight adult mouse strains belonging to these strains were utilized. The bones were photographed and geometric morphometry was applied to these photographs. Principal Component Analysis was applied to determine shape variations. In Principal component 1 for cranium, CD-1 and C57bl/6 strain groups showed different shape variations, while Balb-c strain group showed similar shape variations to the other strain groups. Principal Component 1 for the mandible separated the CD-1 and C57bl/6 strain groups in terms of shape variation. Principal Component 2 explained most of the variation between the C57bl/6 and CD-1 lineage groups. In PC1 for molars, the CD-1 group showed a different shape variation from the other groups. Mahalanobis distances and Procrustes distances were measured using Canonical variance analysis to explain the differences between the lineage groups. These measurements were statistically significant. For cranium, in canonical variate 1, CD-1 group of mouse and Balb-c group of mouse were separated from each other. In canonical variate 2, C57bl/6 group of mouse were separated from the other groups. For mandible, Balb-c group of mouse in canonical variate 1 and CD-1 group of mouse in canonical variate 2 were separated from the other groups. For molars, CD-1 group of mouse in canonical variate 1 and Balb-c group of mouse in canonical variate 2 were separated from the other groups. It was thought that these anatomical differences could be caused by genotypic factors as well as dietary differences and many different habits that would affect the way their muscles work.

Orbital shape in goat and sheep: Symmetric analysis

The aim of this study is to evaluate orbital symmetry in goat and sheep skulls. For this purpose, a total of 83 skulls, including 50 sheep and 33 goat skulls, were used in the study. Geometric morphometry method was applied. For symmetric analysis, one side of each orbit was photographed twice and mirror images were created. There were 36 landmards marked to determine the outer limit of the orbita. As a result of the study, asymmetric components (fluctuating asymmetry and directional asymmetry) for shape were statistically significant in both goats and sheep (p < 0.0001). The first three principal components explained 52.558% of the total shape variation in goats and 61.245% in sheep. This value for symmetric components was 59.095% and 67.742% for goats and sheep, respectively, and 66.791% and 71.154% for asymmetric components. As a result of discriminant function analysis, right and left orbital shapes showed grouping characteristics with similar success rates according to species. Although limited, the right orbit in goats (100%) and the left orbit in sheep (96.5%) were grouped more accurately.

Radiographic analysis of skull in Van Cats, British Shorthairs and Scottish Folds

The most significant bone used in taxonomic research is the skull. This study attempted to identify differences between the three cat species by measuring the skulls of each using computed tomography sections. The study used a total of 32 cat skulls, including 16 Van Cats, eight British Shorthairs and eight Scottish Folds. Van Cat had the highest values for cranial and skull length, whereas British Shorthair had the lowest values. The difference between the British Shorthair and Scottish Fold skull length and cranial length measures was not statistically significant. However, the Van Cat skull length result was statistically different from other species (p < 0.05). Scottish Fold had the broadest head (cranial width: 41.02 ± 0.79 mm). These results demonstrated that the scull of the Van Cat was longer but thinner than that of other species. In comparison to other species, the form of the Scottish Fold skull was more rounded. Internal height of cranium measurements for Van Cat and British Shorthair were statistically significant. In Van Cats, this measurement was 27.81 ± 1.58 mm, while in British Shorthairs, it was 30.23 ± 1.89 mm. Measurements of the foremen magnum were not statistically significant for any species. Van Cat's measures for the foramen magnum were the highest (Foramen magnum height: 11.59 ± 0.93 mm; Foramen magnum width: 14.18 ± 0.70 mm). Scottish Fold had the highest cranial index (Cranial index: 55.50 ± 4.02). Van Cat had the lowest value for this (Cranial index: 50.19 ± 2.16). Van Cat's cranial index value differed statistically from that of other species (p < 0.05). Between species, the foramen magnum index was not significant. None of the index values were statistically significant for Scottish Fold and British Shorthair. Foramen magnum width had the highest age-to-measurement value correlation (r = 0.310), although it was statistically insignificant. Skull length had the highest weight-to-measurement value correlations (R = 0.809), and it proved to be statistically significant. Skull length was the measuring value that distinguished male and female the most clearly (p = 0.000).

Examination of Shape Variation of the Skull in British Shorthair, Scottish Fold, and Van Cats

A variety of skull shapes are frequently used for discrimination between animal species, breeds, and sexes. In this study, skulls of three different breeds of cats were examined by the geometric morphometric method, with the aim of revealing skull shape differences. For this purpose, 27 cats (6 British Shorthair, 7 Scottish Fold, and 14 Van cats) were used. The skulls of cats were modeled by computed tomography. Geometric morphometrics was applied using dorsal (8 landmarks, 63 semilandmarks) and lateral (8 landmarks, 63 semilandmarks) skull projections on these models. Centroid size differences between the breeds were statistically insignificant. However, the differences in shape were statistically significant for both the dorsal view and lateral view. Shape variation was less in the British Shorthair than in other breeds. Shape differences generally occurred around the orbit. In the skull of Scottish Folds, the orbit was situated more caudally than in other breeds. The British Shorthair had the largest orbital ring. In dorsal view, the Scottish Fold had the largest orbital diameter. The orbital ring of Van cats was smallest in both dorsal and lateral views. In the canonical variate analysis, it was seen that the breeds were separated from each other. The shape difference in the skull between different cat breeds could be revealed by geometric morphometrics. The results of this study provide useful information for taxonomy.

Morphometric analysis for the sex determination of the skull of the Deltari Ilir dog (Canis lupus familiaris) of Kosovo

This study aimed to explain the sex determination of the autochthonous dog Deltari Ilir with both morphometric and geometric analysis methods. For this purpose, 24 Deltari Ilir dog skulls (12 females and 12 males) were used in the study. The difference between males and females at 6 values was statistically significant. The most statistically significant difference was seen in the measurement of the greatest breadth of the occipital condyles (p < 0.000). This measurement was higher in male skulls. The next most significant difference was seen in the greatest inner height of the orbit measurement (p < 0.002). This measurement was also higher than for females. In general, the skull length measurements of male dogs were higher than that of females. Male dog skulls had greater skull length and skull height. The lateral view was used for geometric analysis and 14 landmarks were determined. As a result of principal component analysis, 22 PC values were obtained. PC1 accounted for 23.73% of the total variance. As a result of canonical variants analysis, it was observed that males and females were completely separated from each other. The caudal part of the males was wider than the females in geometric analysis. As a result of the study, sex-determining characteristics were revealed for the Deltari Ilir dog. It was seen that gender analysis could be done with both morphometric and geometric analysis methods. In addition, it was seen that morphometric results and geometric analysis results supported each other. Moreover, the results of the study will be useful in the function of comparative anatomy, in veterinary clinical practice, in zooarchaeology but why not also in the veterinary forensic investigation.

Sex Determination in Japanese Quails (Coturnix japonica) Using Geometric Morphometrics of the Skull

Simple Summary

This study aims to determine the sexual dimorphism of quail’s skull by using the geometric morphometric morphometrics and to reveal the shape differences between male and female individuals. For these purposes, photographs of quail skulls in dorsal, ventral, and caudal views were taken and analyzed with the geometric morphometric method. The most significant difference in terms of sexual dimorphism was observed in the dorsal aspect. In caudal view, it was seen that the roof of the skull in females is thinner and longer than in males, but the sex distribution was not decisive compared to other aspects. Geometric morphometrics proved to be a good tool for analyses of the sexual dimorphism and better than traditional morphometrics by their potential way of shape analyses.

Abstract

The study investigated whether there is a morphological difference between the shape of the female and male quail’s skulls. For this purpose, 18 female and 21 male quails were used. After the skulls were obtained, their photographs were taken, and geometric analysis was performed. Dorsal (14 landmarks), caudal (8 landmarks), and ventral (13 landmarks) images of skulls were evaluated. As a result of the Principal Component Analysis (PCA), 28 principal components (PCs) were obtained for dorsal view, 16 PCs for caudal view, and 26 PCs for ventral view. PC1 (41.206%) for the caudal aspect explained the highest shape variation in terms of sex. It was seen that PC1 for dorsal view explained 33.046% and PC1 for ventral view explained 34.495% shape variation. For the dorsal view, the orbital pit of males was found to be deeper than females. The foramen magnum was narrower in female skulls. The lateral borders of the neurocranium were more pointed upwards in males. On ventral view, it was seen that male individuals had a wider skull in shape. Geometrically, it was determined that the male and female distinction was the best in the dorsal view. According to the dorsal view, only one male individual was found to be in the female group, and all other male individuals were completely separated from the females. After the dorsal view, the best distinction was seen ventrally. In the caudal examination, sexual discrimination was not fully seen. In this study, shape differences in quail’s skulls were examined between sexes, and shape differences were revealed geometrically. In addition to traditional morphometry studies, it is thought that geometric analysis studies will add a useful perspective to the literature.