Endocast of Drimolen Paranthropus

https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajpa.25010
The DNH 7 endocast of Paranthropus robustus
from Drimolen,South Africa: Reconsidering the
functional significance of an enlarged
occipital-marginal (O/M) sinus system in
robust australopithecines
Abstract
This paper presents a detailed analysis of
the endocast of one of the most complete
Paranthropus robustus crania known, DNH 7,
from the Drimolen site (South Africa), and
compares it with the morphology of other
australopithecine endocasts. We focus on
endocranial volume, the impressions of
cortical sulci, cranial sutures, and the
pattern of cranial venous sinuses on the
endocast. A noteworthy observation is the
estimated endocranial capacity of 403 cm3,
which is small for an adult Paranthropus.
Fragmentary sulci identified in the frontal
and temporal lobes of DNH 7 exhibit
similarities with patterns observed in
chimpanzees and gracile australopithecines.
We observe the presence of a large remnant
of an occipital-marginal sinus on DNH 7 and
provide an updated table of 13 Paranthropus
endocasts that are scorable for this trait,
which reinforces the hypothesis that an
enlarged occipital-marginal (O/M) sinus
system was fixed across the three species of
Paranthropus. In light of this, the possible
functional significance of the
occipital-marginal sinus system is reevaluated
considering the ontogenetic development of
cranial venous blood flow in human children.
This leads us to hypothesize that the
ontogenetic development of cranial blood flow
in Paranthropus and Australopithecus africanus
infants were different and to suggest that
Taung 1 was the only A. africanus specimen
known to have exhibited an enlarged O/M sinus
system because it was an immature individual.