From Newsgroup: sci.anthropology.paleo


From March.

https://sciencepress.mnhn.fr/sites/default/files/articles/pdf/comptes-rendus-palevol2026v25a3.pdf
Virtual reconstruction and comparative study
of the face of StW 573 (rCLLittle FootrCY)

ABSTRACT
Besides being taxonomically and phylogenetically
informative, changes in the size and shape of
the hominin face through time can reflect
important functional adaptations. Recent discoveries
of well-preserved Australopithecus crania,
particularly StW 573 (rCLLittle FootrCY) from Sterkfontein,
South Africa, have enriched the fossil record.
Although nearly complete, the StW 573 skull has
suffered post-depositional damage, leading to the
displacement and fragmentation of its facial
structures. This study presents a preliminary digital
reconstruction and comparative analyses of the StW 573
face. The skull was scanned at the Diamond Light
Source (United Kingdom), and semi-automated
segmentation was used to digitally separate bones and
teeth from the surrounding matrix, and isolate bone
fragments. The fragments were then digitally
reassembled through visual alignment. The reconstructed
StW 573 face was compared to those of Gorilla, Homo,
Pan, and Pongo, and to the Australopithecus specimens
Sts 5 (Australopithecus africanus from South Africa,
3.4-3.5 Ma) and A.L. 444-2 (Australopithecus afarensis
from Ethiopia, 3.8 Ma), using standard linear
measurements and a landmark-based geometric
morphometric (GM) approach. The dimensions of the
StW 573 reconstructed face, as assessed by the linear
measurements, fall within the ranges observed in
Gorilla and Pongo. Our GM analysis reveals that the
shape of the reconstructed face of StW 573 is more
similar to A.L. 444-2 than to Sts 5, with both fossils
plotting close to extant Pan and Pongo groups in shape
space. In addition to documenting close similarities
between StW 573 and the eastern African Australopithecus
specimen A.L. 444-2, our results provide new insights
into the variability of the Australopithecus facial
skeleton and raise questions on the adaptations and
evolutionary polarity (e.g. ancestral pattern shared
between eastern and southern African Pliocene
Australopithecus) underlying changes affecting the
orbital region within the genus.


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