What anatomical feature can be measured to estimate cranial capacity?

The anatomical feature that can be measured to estimate cranial capacity is the supraorbital torus. This structure, commonly referred to as the brow ridge, is typically found in various hominin species and is indicative of the size and robustness of the braincase. The dimensions of the cranial vault are directly related to the brain size, and in many anthropological examinations, the thickness and prominence of the supraorbital torus can give insights into the brain capacity and the evolutionary adaptations of a species.

Cranial capacity measurements are often taken by assessing the overall size and shape of the skull, and while the supraorbital torus may not be the direct measurement of cranial volume, its characteristics can relate to the skull's overall morphology and thus its internal capacity. Other features of the skull, such as the size of the temporal fossa or the overall dimensions of the cranial base, can also provide information on cranial capacity, but the supraorbital torus serves as a significant anatomical landmark in these discussions.

The other options—molar size, femur length, and mandible shape—do not provide direct measurements of cranial capacity. Molar size relates more to diet and dental morphology rather than brain size. Femur length