Limestone Rock

Limestone is good fossil-bearing rock. But dynamited fragments (often associated with quarries) are hard to date, particularly with radiometric techniques.

This is why the Taung fossil is difficult to date. Faunal correlation (i.e. dating a fossil by association with other fossils whose dates are known) is one way round this, and there are others. But Taung dates are still controversial.

Several recent studies suggest that Taung is younger than once thought - possibly little more than 1 million years BP.

How are Fossils Assigned to Taxa?

Fossils are rarely intact.

• Can taxonomic status be determined from a fragment? If so, how?

Skeletal morphology varies between individuals, even within species. Males and females, for example, often differ in size and proportions. So it is often difficult to tell whether two similar fossil fragments belong to the same or different species. Large samples which show the extent of variation within species are needed, but are often not available.

Furthermore, young individuals from closely related species are often more alike than adults from the two species. The "Taung Baby" has been problematic in all these respects.