442 ASIA, EASTERN AND CENTRAL
have generally found the specimen hard to interpret.
Holloway (2000) quotes an estimated cranial capa-
city of 550-575 ml.MORPHOLOGY
Partial cranium of juvenile, lacking most of lower
part of R side and parts of L temporal, parietal and
occipital. Also lacks much of cranial base and face.
Fairly long a/p relative to height; also quite wide.
Thin, fairly smooth-surfaced cranial bone. Very
difficult to age this specimen, although the fact that
the mastoid process has only just begun to develop
suggests an age equivalent to 5 year-old human. Un-
usual that sagittal suture is already partly synostosed
at such an age.
In profile, skull has short, steep frontal rise; profile
then runs back and up quite sharply to flex downward,
level with mastoid region, into a fairly straight parietal
contour. From front, glabellar and interorbital regions
appear broad; frontal is smoothly curved from side to
side. Parietals more angulated in posterior view. Top
of skull relatively flat, dropping off sharply at sides
and also at rear, about two-thirds along sagittal suture.
Most posterior point occurs at juncture of occipital
and nuchal planes; below this juncture, bone curves
smoothly but strongly anteriorly until undercut by a
distinct depression. Area above lambda is quite flat
across. From above, cranium is very narrow anteriorly,
broadening quite markedly posteriorly to reach widest
point about level with mastoids. Seen from behind,
cranium is rather wide and not very tall; probably was
widest above mastoids.
Region of glabella was wide and probably some-
what bulbous. Interorbital region was probably quite
broad. As seen on the L, a distinct, rather deep notch
is situated medially on the superior orbital margin, lat-
eral to which anterior surface of superior margin arcs
forward and around to the side. Lateral supraorbital
area quite protrusive, but remains thin and shelf-like
(not thickened and bar-like). No evidence of frontal si-
nus development in medial area of orbit. Behind lateral
orbital margin is a short but distinct constriction. As
seen on the L, the medially placed supraorbital notch
is relatively deep but becomes shallower laterally,
Orbital roof very concave; curves sharply down to the
thin, downwardly pointing superior orbital margin. As
seen on the L, orbital cone is very long; moderate optic
foramen and small inferior orbital fissure lie at its apex.
No superior orbital fissure visible, even though area is
intact. From L side, the very shallow posttoral sulcus
becomes more evident laterally; curves around sharply
laterally into postorbital constriction. Faint temporal
line runs up side of supraorbital “torus,” then turns
back sharply to fade out rapidly, low on side of skull.
Also as seen on the L, temporal fossa is short a/p;
becomes deeper but more constricted a/p from top to
bottom. No sharp delimitation between temporal and
infratemporal fossae; instead, there is a fairly smooth
flexure between upper and lower surfaces.
As seen on the L, articular fossa very deep, wide
m/l, and long a/p (particularly for an individual this
young). On both sides, articular fossae closed off medi-
ally by wall of bone (not tubercle). Anterior surface of
fossa flows smoothly out onto bone in front. Posterior
root of zygomatic arch (as seen on L) takes origin at
midpoint of articular fossa. From side, arch seems to
have had an upward posterior curve; was probably quite
thin s/i, did not flare much laterally. Ectotympanic tube
not fully ossified laterally; bears a low, blunt vaginal
process along its central axis. As better seen on the R,
vaginal process peaks halfway along ectotympanic tube,
then stops. Bone of ectotympanic surprisingly thick for
such an apparently young individual. On the R, mas-
toid process is visible; has only just begun to develop.
Occipital was very wide, moderately tall s/i, with
smooth curve of lambdoid suture (as seen on L) up to
lambda. Nuchal plane steep; central portion strongly
depressed by twinned, quite broad, deep fossae.
External occipital crest not strongly defined. Base of
skull preserves parts of R and L petrosals. As seen on
the L, carotid foramen large, ovoid; points posteri-
orly. No reliably identifiable sphenoid foramina visi-
ble apart from carotid foramen. Body of petrosal does
not flex strongly upward but remains rather straight
and is angled slightly forward. On both sides, below
and slightly medial to medial margin of carotid fora-
men, is a blunt, tubercle-like elevation of bone.
Sagittal suture quite closed in preserved central
portion but less so posteriorly; also, where preserved,
is shallowly and broadly interdigitated but not seg-
mented. (Early closure of sagittal suture indicates
width would have been emphasized during growth
because vault would enlarge at right angles to prema-
turely synostosed sutures.) Coronal suture appears to
have been open and poorly interdigitated; was appar-
ently not segmented. Lambdoid suture was also
open; as seen on the L, it was broadly but shallowly
interdigitated but not segmented.