Ventral Arc
Definition
An elevated ridge on the anterior (ventral) surface of the pubic bone, curving from the pubic symphysis toward the ischiopubic ramus. Present and prominent in females; absent or indistinct in males.
- Location
- Anterior (ventral) surface of the pubic bone
- Present in
- Females, elevated and well-defined
- Absent/indistinct in
- Males
- Method context
- One of the Phenice (1969) sex-estimation traits
Common questions
Why is the ventral arc considered one of the more reliable sex traits in the Phenice method?+
The ventral arc, along with the subpubic concavity and ischiopubic ramus ridge, was found in the original Phenice study to give high classification accuracy from the pubic bone alone, and it develops from a distinct pattern of bone remodelling during female pelvic growth that has no equivalent process in males.
What can make the ventral arc difficult to score on a given specimen?+
Postmortem damage to the fragile anterior pubic surface, incomplete recovery of the pubic bone, or juvenile remains in which the trait has not yet fully developed can all make the ventral arc unscorable, which is why Phenice-method estimates rely on multiple pelvic traits rather than this one alone.
Related terms
- Greater Sciatic Notch
- The posterior notch on the ilium between the posterior inferior iliac spine and the ischial spine. Narrow and V-shaped in males; wide...
- Klales 2012 Revision
- An ordinal revision of the Phenice method by Ashley Klales using a 1-5 scale for each trait and a logistic regression to...
- Obstetric Trade-Off
- The evolutionary conflict in humans between the biomechanical benefit of a narrow pelvis for efficient bipedal locomotion and the obstetric requirement for...
- Phenice Method
- A non-metric morphological sex estimation technique published by Thomas Phenice in 1969, based on scoring three traits of the pubic bone: the...
- Pre-Auricular Sulcus
- A groove anterior to the auricular surface of the ilium, associated with parturition stress at the sacroiliac joint. Present in 58-70 per...
- Subpubic Angle
- The angle at the inferior apex of the pubic arch where the two inferior pubic rami meet. Acute (below 90 degrees) in...
- Subpubic Concavity
- A medial inward curve on the inferior aspect of the ischiopubic ramus in females, resulting from the wider sub-pubic space. Absent (straight...
- Terry Collection
- A documented skeletal collection at the Smithsonian National Museum of Natural History (Washington DC), assembled from cadavers donated to Washington University's anatomy...
- Walker 2005 Scale
- A five-point ordinal scoring system for the greater sciatic notch published by Philip Walker, ranging from 1 (very narrow, most male) to...