On the variability of skull shape in German shepherd (Alsatian) puppies

Abstract

In this study the skulls of 32 German shepherd puppies (40 -107 days old) were examined. They were divided into three age groups (40 -49, 50 -69, and 70 -107 days) and the variability of their shapes was determined. Some geometrical shapes were drawn by joining the measuring points. Angle measurements were made on these shapes, which comprised the whole skull, neurocranium, and viscerocranium. The skull index was further calculated in order to assess the correlation, if any, of this index with the angle measurements. It was found that the length of the skull increased more than the width, and, accordingly, the skull became narrower and longer with age. Furthermore, the AZP and AZN angles widened with age, while the ZAZ, ZPZ, NcANc, NcPNc, NcBrNc, SwNSw, and SwPSw angles decreased. The decrease in the skull index, which was not proportionate to the age, showed that the zygomatic width did not increase as much compared to the length of the skull. Anat Rec Part A 272A: 460 -466, 2003.

Rostro-dorsal and rostro-lateral skull morphologic variability in three age-groups of the Egyptian mongoose (Herpestes ichneumon) (Linnaeus, 1758): implications of certain orbital parameters — angular geometric approach

“…A wider MZW in comparison to PL conferred a higher skull index on this group; this value did not increase proportionately with skull profile length in adults resulting in a subsequent decline for the value in adults of this species, suggesting a more transverse growth than longitudinal in juveniles, but a reverse in pups. Our observation was corroborated by similar investigation in dogs by Onar and Gunes [27]. The interrelationship between angle measurements is consistent with the fact that slender rostrofacial morphology is exhibited by pups with anterior spherical shape of the orbit while juveniles display a more robust morphology due to zygomatico-maxillary changes whereas strong facial expressions structures are demonstrated in adults.…”

“…It was noted that some architectural construction such as the manifestation of the prominent dorsal orbital ridge, the lacrimal tubercle and the maxillary process of the zygomatic bone occurs between late adolescence and adulthood along with SI reduction. A relatively wider MZW in juveniles compared with PL was responsible for a high SI in the group; this value however did not increase proportionately with increasing age in adult group hence the fall in index value in adults suggesting a maximum horizontal growth but minimal perpendicular (vertical) growth as was confirmed in a similar canine study [27]. The angular measurements correlations to each other demonstrate the directions of growth shape in H. ichneumon skulls and establishes the fact that nose extends beyond the premaxilla [19].…”

“…The post orbital region becomes narrower and shorter but expands postero-laterally. Though both the dorsal and ventral components of the skull play some roles in crania modelling processes [8,25], this has been extensively investigated in other canids [27]. However, this study has only discussed dorso-rostral cranial changes in a geometric perspective and the authors believe that such geometric observations validate explanations on shape allometric changes during skull growth.…”

Morphometrical Studies on the Skull of Indian Blackbuck (Antelope cervicapra)

“…These studies have been undertaken in many domestic species such as the dog (Onar & Günes, 2003;McGreevy et al, 2004), cats (Künzel et al), goats (Olopade & Onwuka, 2004, 2009a, 2009b, horses (Evans & McGreevy, 2006) and sheep (Pare´s et al, 2010) in an attempt to provide baseline anatomic information and evaluate implications for physiological functions and clinical importance (Olopade & Onwuka, 2009a). The skull has also been used as a major skeletal structure to determine taxonomic affiliations as it is subject to phenotypic changes because of selective breeding (Bruenner et al, 2002).…”

CRANIOMETRIA EM LOBOS-GUARÁ Chrysocyon brachyurus ILLIGER, 1815 (CARNIVORA, CANIDAE)

“…Os critérios, medidas e índices cefálicos utilizados neste estudo foram baseados em trabalhos de avaliação craniométrica em cães domésticos (2,(6)(7)(8)(9) . As avaliações foram realizadas com auxílio de paquímetro manual Starrett 125 MEB.…”