S AN G I RAN 485
tube itself. On the R, there apparently was a shallow
depression medially, further delineating this bulge
posteromedially (rather like digastric fossa), although
it does not continue anteriorly as a distinct notch.
Internally, frontal crest is moderately long and low
(except for its most inferior extent). Inner table of
bone corresponding to superior surface of frontal
lobes is quite elaborately sculpted, bearing a series of
undulations. Superior sagittal sinus becomes visible at
region of bregma and proceeds as a thin groove,
bounded at times on one side or the other by a low,
thin bony crest. Posteriorly, within occiput, midline
bone thickens into a stout internal occipital crest,
which intervenes between a pair of deep occipital im-
pressions. Both petrosals broken anteriorly. Small
arcuate eminence present on the L and a larger, more
swollen one on the R. Especially on the R, groove for
superior petrous sinus is well developed. Region
of subarcuate fossa creased but fully closed off. Sub-
subarcuate fossa large and also closed off (both sides).
Huge cochlear canaliculus exposed; a large jugular
fossa lies posterolateral to it. Sigmoid sinus deep and
well excavated on both sides; comes straight down be-
hind petrosal; groove or crease across petrosal appears
to be branch of sigmoid sinus. No grooves for trans-
verse sinuses. Anterior branch of middle meningeal
artery appears to have run along coronal suture; poste-
rior branch runs right to apparent region of lambda.
All sutures, except squamosal and parietomastoid,
are undetectable.
Sangimn 3. Consists of a fairly complete R parietal,
medial part of L parietal, and part of occipital plane in
midline. In general, bone not notably thick. In what is
preserved, cranium appears tapered anteriorly in
coronal section; was low and broad; the relatively flat
superior contour is punctuated by a low sagittal keel
(cf. S4). Anterior branch of middle meningeal artery
parallels coronal suture (cf. S2); posterior branch runs
to region of lambda (cf. S2). Occipital fragment
preserves only a small portion of angle between
occipital and nuchal planes (cf. S2).Sungirun 4. Consists of crushed, heavily recon-
structed neurocranium with part of middle cranial fossa
and all of posterior cranial fossa. Parietals and part of
occipital are together; base of skull is a separate piece.
Also an allegedly associated isolated maxilla with
R C-M3, L C-M1, and part of inferior nasal region.
Bone surrounding cranial fossae is very thick;
bone of skull roof is very thin. Braincase quite broadacross supramastoid regions and very low vertically.
Sides tilt inward above supramastoid region; superior
contour very broad, elevated along midline by a dis-
tinct keel that broadens toward lambda but fades out
just before reaching it. Sagittal profile quite evenly
curved down to angle at skull rear, where there is a
distinct ledge at point of inflection. Nuchal plane
slopes down as well as forward.
Squamous suture was long. Apparently no anterior
squamosal corner, so no differentiation between tem-
poral and infratemporal fossae. As seen on the L, a
sinus invades superomedial portion of alisphenoid.
Articular fossae deep, broad mfl and angled slightly
obliquely anteriorly. Articular fossae closed off medi-
ally by an extension (not thickened) of temporal bone.
Articular eminence flat; flows directly into plane of
temporal fossa. Posteriorly, articular fossae bound by
tall, inferiorly distended anterior face of ectotympanic
tube. Posterior zygomatic root originates just in front
of very tall, a/p compressed auditory meatus. On the
R, meatus is appressed to anterior face of long, paral-
lel-sided, very projecting, slightly anteriorly facing
mastoid process. Tube narrowly triangular in cross-
section; sharp apex of triangle is distinctly separated by
deep notch from anterior face of mastoid process.
Tubes quite short laterally; as seen on the R, barely ex-
tend beyond medial face of mastoid process. Groove
for styloid process thin and very medially placed, lying
just medial to most projecting part of ectotympanic
tube. Stylomastoid foramen small, lies lateral to styloid
pit. Moderately sized carotid foramen is even more
medially placed, with a very small jugular foramen just
behind it. Both foramina shared same aperture. Small,
round foramina ovales are contained in sphenoids, sur-
rounded by a thick wall of bone. On both sides, a
moderately large, elongate foramen spinosum appears
to lie in petro- squamous suture.
Damaged suprameatal crests were very large and
flowed into smaller, less distinct supramastoid crests be-
hind. Both crests essentially horizontal. Supramastoid
crest ends level with, but well anterior to, a slightly me-
dially tilted, not very deep parietal notch. Mastoid
process bears a long crest that sweeps up and back from
a low bulge lying well above tip of process. Long axis of
mastoid process is quite medially oriented; axis paral-
leled internally by what seems to have been a narrow
but modestly well-excavated mastoid notch. Broad,
long swelling lies medial to notch; notch delineated
medially by long, broad sulcus. Medial to sulcus, bone
swells out somewhat. No well-defined external occipital