Analysis of the sexual dimorphism in the basiocciptal portion of the dog’s skull

Abstract

Sexual differences in the basioccipital portion of the skull of dogs have been described and an index is presented which reliably predicts the sex of the skull. 92 dolichocephalic skulls (44 male, 48 female) from mongrel dogs were used. In the basioccipital region of the male skulls, a triangular area, which extends from the basion to a line joining the medial-most points of the two jugular foramina, appears narrow and elevated. The pharyngeal tubercle is also prominent. In female skulls the rostral angle of this triangle is wider and the triangular area seems smoother and flat. The anterior half of the female basioccipital portion is wider and smoother than in the male skull. In order to quantify the observed differences, four indices were calculated. All of the indices were statistically significant. However, only index IV could be reliably used in predicting the sex of an unknown skull: breadth IV × 100 Index IV = length II was derived from breadth IV (distance between the two temporo-occipital fissures at their lateralmost points) and length II (distance between the basion and a line drawn between the two medialmost points of the jugular foramina in the midline). Values of less than 123 for male and greater than 136 for female placed the skulls in their proper sex group. Skulls that had intermediate values could be placed in correct sex grouping only in conjunction with strong observational criteria. It is suggested that in absence of such strong observational criteria these skulls may belong to immature or castrate animals.

Skeletal remains of dogs unearthed from the Van‐Yoncatepe necropolises

“…It was thereby ascertained whether the skulls might belong to the dolicho-, meso-or brachycephalic group. The sex of the dogs, on the other hand, was determined through measurements of the basioccipital and examination of surface traces (The & Trouth, 1976;Trouth et al, 1977).…”

“…The appearance of this triangular-like area can be classified into two types (The & Trouth, 1976, Trouth et al, 1977:…”

Osteometric Variation in Domestic Dogs (Canis familiaris ) from the Kodiak Archipelago, Alaska

“…Canids tend to show some degree of sexual dimorphism that can be determined osteologically, although breeding among domestic dogs can complicate sexing (Crockford, 1997;Ruscillo, 2003). According to previous analyses of domestic dog osteology, the humerus (Ruscillo, 2003), pelvis (Shigehara et al, 1997), mandible (Shigehara et al, 1997) and cranium (Trouth, 1976;Trouth et al, 1977;Shigehara et al, 1997) may be used to determine the sex of a particular specimen with some certainty.…”

Osteology of theKuriMaori: the Prehistoric Dog of New Zealand

“…Determination of sex from canine remains which are fragmentary and disarticulated, as is the case for the kuri, is only possible using the cranium (The & Trouth, 1976;Trouth et al, 1977). There is no established Figure 1.…”