486 ASIA, EASTERN AND CENTRAL
protuberance. Region of external occipital crest is
bordered near foramen magnum by a pair of deep, well-
defined fossae, and nearer to occipital angle by a
broader, shallower pair of depressions. This crest is less
distinct in the intervening space. Viewed from behind,
these depressions form a “peaked bow-shaped” configu-
ration, peaking in midline below. Foramen magnum
very long and ovoid. Occipital condyles long and
appear to have had some arthritic deformation.
Virtually continuous suture back and up from pari-
etal notch, straight to lambda. This lambdoid suture is
low, peaks flatly at lambda, and is poorly denticulate
and unsegmented. Posterior part of sagittal suture has
two segments; the part emanating from lambda is
shallowly wavy, and the segment in front is deeply in-
terdigitated. Back of skull is most distended within the
occipital region itself. Occipital plane descends almost
vertically from lambda to angle sharply out and back at
a point more or less level with suprameatal crests,
where bone is very thick. In midsagittal profile, this
produces a marked ledge above, with distinct bulge un-
derneath. Bulge bulkiest in midline, tapering upward
laterally, corresponding to bow shape produced by de-
pressions below. (However, ledge formation looks as if
it might be artificial.) Viewed from below, the bulging
the ledge decreases in prominence, fading out well be-
fore reaching the probable area of asterion. Only the
central area, delineated both above and below, could be
characterized as an occipital torus.
Internally, the superior sagittal sinus is well defined
only dong the small posterior segment of the sagittal
suture. Region of internal occipital protuberance is mas-
sive; the only indication of a transverse sinus lies well
lateral to it (on R). Transverse sinus curves down and
forward as a moderately impressed sigmoid sinus that
appears to fade out in anterior portion of cerebellar lobe
depression. On the L, sigmoid sinus is noted only from
below posterior extremity of petrosal; it also fades out in
the anterior portion of cerebellar impression. As seen on
the R, region of arcuate eminence is minimally elevated;
superior petrous sinus is long and distinct. Groove for
superior petrous sinus not visible in preserved posterior
portion of L petrosal. Subarcuate fossa region filled in
and flat. Broad, crease-like sub-subarcuate fossa on both
sides (appears to represent branch or continuation of
sigmoid sinus). Below region of arcuate eminence (on
both sides), on inner aspect of petrosal is a deep, moder-
ately long horizontal sulcus that runs to an aperture
extending below level of internal auditory meatus. Aper-
ture more extensive on R than L. As seen on the R,
most of perimeter of aperture is intact, with carotid
foramen and jugular fossa continuous through it.
Carotid canal apparently incompletely ossified; would
have opened into region of foramen magnum, not more
anteriorly; i.e., carotid canal did not run through length
of petrosal. (Since jugular foramen can be reached only
through fissure in petrosal below internal auditory mea-
tus, and lateral extremity of this fissure lies within
groove-like sulcus below region of arcuate eminence,
this suggests that sinus drainage was not a simple, single
jugular conduit; rather, it appears there was bifurcation,
with one channel going through petrosal fissure to jugu-
lar fossa and the other continuing down as inferior
portion of sigmoid sinus. In the latter case, the only exit
available for drainage was presumably the foramen mag-
num.) Cerebellar lobes deeply impressed, downwardly
pointing. Posterior poles of cerebrum very shallow, point
straight backward.
Sungirun 10. Partial calotte (subadult?) missing
most of frontal, with isolated L zygoma and part of R
supraorbital region and lower frontal plane. In occipital
region, specimen looks like S12, and in sagittal keel
like S3 and S4. Skull small and short (S2), quite high;
frontal would have risen to highest point in strong
curve. Parietal bulges slightly (S2, S3). Occipital was
quite wide, not very tall (S2, S4). Temporal lines faint
(S2). Modest distinct occipital torus near midline is
delineated below by a shallow undercutting of nuchal
plane that is highlighted by a slightly double-arched
nuchal line, and above by a swelling of its superior
surface (S12). Isolated R frontal preserves what seems
to be midsection of s/i tall supraorbital torus (S17).
Frontal appears to have risen steeply from right behind
torus (S17). Frontal lobe did not extend over full
length of orbital cone. Isolated, quite gracile L zygoma
fragment lacks temporal process and maxillary root.
Body slightly swollen externally; lacks malar tubercle
(S17). Inferior margin of orbit probably lay well above
plane of superior margin of zygomatic arch (S17).
Lateral margin of orbit was probably quite vertical,
curving smoothly below into inferior orbital margin
(suggesting further that lower face of S17 was
compressed upward?). Zygomatic arch may have
bowed laterally to some extent (S17).Sungirun 12 (Pithecanthropus 7). Calotte lacking
most of frontal and sides. Quite small, but relatively
thick boned. Braincase very long, very low, and very
wide at back (S2, S4). Occipital “toru~” appears to
have distinct upper and lower margins (S4, S17).