![]() |
|||||||||||||
|
Cranial capacity |
Cranial capacity is a measure of the volume of the interior of the cranium (also called the braincase or brainpan) of those vertebrates who have both a cranium and a brain. The most commonly used unit of measure is the cubic centimetre or cc. The volume of the cranium is used as a rough indicator of the size of the brain, and this in turn is used as a rough indicator of the potential intelligence of the organism. However, larger cranial capacity is not always indicative of a more intelligent organism, since larger capacities are required for controlling a larger body, or in some cases are an adaptive feature for life in a colder environment.
Examples of cranial capacity:
Examples of early hominids:
| Taxon | Size (cc) | Number of specimens | Age (megannum) |
|---|---|---|---|
| Australopithecus afarensis | 438 | 4 | 3.6–2.9 |
| Australopithecus africanus | 452 | 7 | 3.0–2.4 |
| Australopithecus boisei | 521 | 1 | 2.3–1.4 |
| Australopithecus robustus | 530 | 1 | 1.9–1.4 |
| Homo habilis | 612 | 6 | 1.9–1.6 |
| Homo rudolfensis | 752 | 1 | 2.4–1.6 |
| Homo ergaster | 871 | 3 | 1.9–1.7 |