Biology Reference
In-Depth Information
tion, and publication of the little endocast and skull in a landmark paper
that appeared in the leading British scientific journal,
Nature,
on Febru-
As Dart saw from the start, the broken front end of the endocast fit per-
fectly into one of the rock fragments that also revealed a tantalizing bit
of lower jaw, which presumably belonged with the endocast. Hoping that
the rocky matrix also contained a face, Dart worked laboriously to free
its bony contents. His tools were a hammer, chisels, and his wife's knit-
ting needles, which were used to peck and scrape the lime-consolidated
earth from the encased bones. When the outer sides of the upper and
lower jaws were finally exposed, Dart was convinced that the fossil's face
would also emerge. “No diamond cutter,” recalled Dart, “ever worked
more lovingly or with such care on a priceless jewel—nor I am sure, with
such inadequate tools. . . . On December 23, the rock parted. . . . What
emerged was a baby's face, an infant with a full set of milk (or deciduous)
teeth and its first permanent molars just in the process of erupting. I
doubt if there was any parent prouder of his offspring than I was of my
As he analyzed his find, Dart realized that no one had ever before set
eyes on such a fossil (figures 3 and 4). Dart estimated from the teeth that,
rather than actually being a baby, the individual had died at around six
years of age. (Using different methods, scientists today believe an esti-
mate of about three and a half years is more likely.) The skull revealed
an unprecedented combination of humanlike and apelike features. Like
humans and unlike apes, it had a rising forehead, round eye sockets, and
a short nose. It also lacked an apelike ridge of bone (brow ridge) over the
eyes. However, the bottom of the nose resembled that of a chimpanzee,
and the lower part of the face protruded, as is typical of apes, but to a
lesser degree. Most of the features of the jaws and teeth that could be
seen (the upper and lower jaws had not yet been separated) resembled
those of humans rather than apes. For example, the canines were small,
and the inside of the lower jaw lacked a bony shelf that appears in apes.
The brain, however, was the size of a chimpanzee brain, and this could
