Associated skeletons, which are specimens preserving more than
one body
part from the same individual,
are especially important for taxonomic and functional analyses. This
study concentrates on the subset of
associated skeletons which preserve the reciprocal surfaces of a
joint. It uses laser scanning to explore
whether the shapes of the reciprocal surfaces of a joint of an
individual are significantly more congruent
than the surfaces of randomly-matched pairings taken from the same
species. Laser scanning was used to
capture the distal articular surface of the left tibia of OH35
and the trochlear articular surface of the talus
of OH8, both from Bed I, Olduvai Gorge, Tanzania. The degree of
congruency between those articular
surfaces was tested against the congruency of the talocrural joint
of AL 288-1 (Australopithecus afarensis),
and the congruency of both associated and randomly-matched
talocrural joints of modern humans,
chimpanzees and gorillas. The results suggest that OH35 and
OH8 do not come from the same individual
and may not come from the same species. Although this
analysis leaves open the taxonomic affinity of
OH35, it demonstrates the potential of laser scanning
for capturing 3D data in palaeoanthropology. It also
demonstrates the potential for using the relative
congruency of reciprocal joint surfaces as a test of the
likelihood that isolated limb bones are components of a single individual.