S AN G I R A N 491
(S2). Externally, major remaining feature is a markedly
posteriorly and inferiorly protruding structure in the
area of the external occipital protuberance (S4).
Thickened, protruding occipital torus (S4) delineated
above and below (S4, S17) and peaks downward
between two broadly scalloped fossae (S17).
Sungirun 41. Highly eroded calotte missing an-
terior bits of frontal. Bone thin to moderate. General
profile quite reminiscent of S2 but more high vaulted,
with sharp rise of frontal in front and a curious
configuration around junction of the occipital and
nuchal planes. From rear, very wide; looks almost
identical to S10 (with sagittal keel and configuration
of occipital torus). Parietal notch shallow (S2, S4).
Sigmoid sinus contained entirely within temporal
(S26 et al.).
Sangirun Sb 7904 A and B. Fragment of (?) R
occipital with some of occipital plane and nuchal
plane; also fragment of presumed parietal; weathered,
Some angulation between occipital and nuchal
planes (S2).
Maxillary Fragments
Since there are only two fragmentary maxillae, they
are described individually.Sungirun Pd. L maxillary fragment containing
broken P1 and 2, alveoli for C and 12, and partial
alveolus for 11. Clivus appears to have been vertical
and probably somewhat curved across. Surface
crushed and weathered, with some indication of a
canine fossa. Alveolar margin moderately thick. Palate
was probably quite deep. Alveolus for I2 much smaller
than that for I1 would have been. C alveolus suggests
a huge, vertically emplaced root. P1 crown split apart;
even so, it is likely this tooth was wider b/l than P2,
which is less severely split. P1 and 2 paracone slightly
internally placed; apex lies directly opposite apex of
protocone. Lingual surface slightly convex; buccal
surface virtually straight. Angulation between para-
cone and protocone identical in both Ps. P2 bears a
small posterior fovea, and a few more enamel creases
than P1. Occlusal outline of P2 almost oblong, with
very little indentation on distal side.
Sungirun 15b. Fragment of R maxilla with alveoli
for I2 and C, roots of P2, and worn P1. Tiny area of
nasal floor preserved. Floor of nasal cavity was
probably sunken to some extent. Nasoalveolar clivus
short, probably quite vertical. Lateral part of nasalfloor smooth; arcs gently in sagittal plane to a slight
corner with clivus. Maxillary sinus probably extended
as far forward as region of P2. Distinct depression
externally between roots of P1 and P2. Sides of palate
sloping. I2 root slightly m/d compressed; was deep b/l
and bore longitudinal sulcus distally. C alveolus quite
long and large, suggesting robust root. P1 probably
had long, splayed roots. P1 crown very worn; buccal
side seems to have sloped in so that tip of paracone
would have been slightly internally placed. Also
appears that apices of paracone and protocone were
slightly mesially placed, opposite one another.
Posterior fovea narrow m/d. Two P2 roots were quite
long and very splayed.Mandibular Fragments
Sangiran lb is clearly morphologically distinct from
the others, and is described first and separately. De-
scriptions of the specimens that follow it are provided
because these fossils not only have been thought of as
hominid but, in some cases, have been proposed as the
type specimen of a hominid genus and/or species.Sungirun 1 b. R mandibular corpus almost from
midline to just behind M3. Preserves alveolae of
I2-P1, and crowns of P2-M3.
Corpus long and tall s/i compared to b/l width.
Front of jaw would have been quite narrow and
strongly curved across; tooth rows are noticeably diver-
gent posteriorly. Postincisal plane probably continu-
ously sloping from top to bottom. Below P2-M1, infe-
rior border is noticeably concave due to development
of a very m/l wide digastric fossa that occupies entire
inferior border. At least three small mental foramina:
one under region between P1 and 2; other two below
P2-M1, one right above the other. Ramus begins to
rise between M2 and 3; its anterior border may only
just have obscured back of M3. Not much mandibular
gutter. Internally, mylohyoid line almost imperceptible.
Submandibular fossa below is very shallow. Internal
alveolar crest blunt and passes close to M3.
Alveolae for 12-C compressed m/d. C and I2
alveoli essentially subequal in size. P1 alveolus only
marginally larger. Occlusal surfaces of all crowns badly
weathered, obscuring details of morphology. P2 has
slightly sloping buccal surface and straighter lingual
surface; fairly square with rounded corners in occlusal
outline. Metaconid small and quite mesially placed;
appears to have been in front of larger protoconid.
Short cristid runs between metaconid and mesial side