STERKFONTEIN 265
descending from it and apparently also lay in a depres-
sion. As reconstructed, anterior root of zygomatic arch
takes origin close to alveolar region of Ml and curves
out strongly laterally. Also as reconstructed, zygoma
itself would not have been very tall.
Nasal aperture moderately large for a specimen
this size); it is quite narrow superiorly and very broad
inferiorly compared to its height, with blunt, rounded
inferolateral corner. Lateral nasal wall on the R bears a
distinct concha1 crest, low down and situated well
back. Nasoalveolar clivus relatively flat, long, descend-
ing steeply from what was apparently an obtusely an-
gled junction with nasal cavity floor. Anterior nasal
spines were apparently quite bulky. Well behind and
below them are large, backwardly facing incisive
fossae (thus there is some stepping down into nasal
cavity). Maxillary sinus on the R penetrates far into
nasoalveolar clivus; on the L, it extends posteriorly
beyond M3. On the R is a very long, posteriorly in-
complete lacrimal groove, probably roofed by bone.
Palate shallow anteriorly; it deepens posteriorly
only modestly and has sloping sides. Incisive foramen
large and depressed; lies level with P2, and continues
anteriorly to base of Is as depression with bony mid-
line ridge. As reconstructed, dental arcade is relatively
broad, gently curved across front, and parallel sided.
RP1-M3 heavily worn and slightly damaged; LPl
and 2 and M2 and 3 heavily worn, damaged; alveoli of
RC-L12 as well as LMl present. Anterior tooth alve-
oli large, especially C. All anterior teeth would have
been very long, stout rooted, and also probably large
crowned. There was probably only a little incisor het-
eromorphy. P1 and 2 appear large relative to M1 and
divergently three rooted; crowns were much wider b/l
than long m/d. Both Ps had some stylar development
on either side of paracone. P2 was slightly longer m/d
than P1. Ms increase in size from Ml to M3. At least
M2 and 3 had large hypocone. M3 had thick postcin-
gulum, diminished metacone, and a deep pit distally
on lingual surface of protocone.
stw 53c
Glued fragment of R zygoma plus adjacent maxilla
(does not match small piece of zygoma preserved on
maxilla StW 53b). Shows more vertical descent of
inferior margin toward tooth row (different individ-
ual?). Maxillary sinus extended at least to region of
zygomaticomaxillary suture. Masseteric scars on max-
illary margin of zygomatic arch laterally facing. Ante-
rior margin of arch probably rose quite steeply. Infront of masseteric scars is a small, well-defined, infer-
olaterally facing maxillary tuberosity. Temporal fossa
was probably conical, narrowing inferiorly.StW 53d
Fragmentary, reconstructed, and quite distorted R
temporal, part of posterior R parietal, and a bit of R
occipital. Cranial bone moderately thick. From a
larger individual than preceding pieces, and also
lighter in color.
Indicates somewhat tall s/i, posteriorly globular
braincase with straight and fairly vertical side walls and
laterally bulging supramastoid region. Greatest width
across mastoids. Seems that squamosal was quite short
a/p, with a broad, probably fairly vertical parietal
notch. Parietomastoid suture apparently somewhat
long. Part of superior nuchal line is preserved and
forms a reasonably well defined corner between the
more or less vertical occipital plane and the long,
slightly angled nuchal plane. Articular fossa somewhat
wide m/l, deep, long a/p, with sloping anterior and
posterior walls. Anterior wall of fossa steeper and
bounded by a modest articular eminence. Posterior
wall of fossa bulged out by transversely oriented ecto-
tympanic tube. Laterally, the articular fossa is displaced
outward under the posterior root of the zygomatic
arch; medially, it is bounded by the thin, inwardly
curving flange of temporal. Postglenoid plate small and
lies far laterally. Suprameatal crest sharp; flows from
supramastoid crest into the quite strongly divergent
posterior root of the zygomatic arch, whose superior
shelf widens anteriorly. Tubular ectotympanic bears
crease-like vaginal process posteriorly along its length.
Vaginal process lies well anterior to mastoid process
and may have reached edge of auditory meatus. Audi-
tory meatus appears to have been very large, oval, with
well-developed suprameatal crest above. Posterior sur-
face of mastoid process slightly obliquely oriented and
separated from long, swollen supramastoid crest by s/i
tall, very shallow sulcus. Process very broad, s/i tall,
flat, anteriorly directed, with fairly sharply pointed tip;
projects a bit below cranial base. Lateral surface of
mastoid process is distended by a blunt crest that runs
its full length. Mastoid notch is deep, m/l broad, a/p
short, partly bounded posteriorly by faint ridge. Notch
bounded medially by low, a/p short, paramastoid crest.
Well medially is a slight occipitomastoid rise; medial
to this is a thin Waldeyer’s crest. Anteriorly, the mas-
toid notch flows into depression separated by an
oblique elevation of bone from a shallower depression