266 APRI (:A
medial and slightly anterior to it. Difficult to deter-
mine whether either depression is a styloid pit; equally
difficult to identify stylomastoid foramen. What ap-
pears to be part of jugular foramen lies level with and
medial to these depressions. Carotid foramen had been
even more medially situated.
Internally, superior surface of petrosal quite flat
and moderately broad, with no sign of superior petrous
sinus; internal surface broken. Portion of large, vertical
sigmoid sinus visible posteriorly. R occipital lobe fossa
extends down quite far. Some faint but nonarborizing
posterior branches of middle branch of middle
meningeal artery are visible high up.
StW 53e
Multiple pieces of braincase bone glued together, rep-
resenting part of occipital and parts of parietals. Large
anterior piece may not belong with rest (strong, medi-
ally curving temporal line on middle piece may not
continue onto front one).
Anterior piece flat; probably comes from side wall.
Middle piece has strong temporal line externally and
four meningeal grooves internally. Curvature of this
piece, plus position of grooves, suggests it is from pos-
terior part of L parietal. Third piece is from occipital
bone; it preserves part of a weakly interdigitated L
lambdoid suture and part of the superior nuchal plane
with a strongly pointed, wedge-shaped, downwardly
oriented external occipital protuberance. As seen on
the L, fairly short but strong superior nuchal lines flow
into this protuberance.This region is also undercut by
the steep nuchal plane. If these pieces do go together,
this occipital piece should be placed lower down than
currently reconstructed. Also, occipital protuberance is
not in line with sagittal suture. Internally, impression
for L occipital lobe is shallow; with part of transverse
sinus, it suggests occipital lobe was small.
stw 53f
Part of lateral portion of occipital, preserving L rim of
foramen magnum and part of occipital condyle, plus
jugular notch and anterior condylar foramen. Foramen
magnum would have been heart shaped and relatively
small, with short, anteriorly placed, strongly arced
condyle.
StW 53g
Fragment of petromastoid. Mastoid process swells
laterally, with a gutter between it and the bulging
supramastoid crest above (as in StW 53d). Low,
crease-like vaginal process lies on posterior surface of
ectotympanic tube and is separated from mastoid
process. Mastoid process very flat, and broad on pos-
terior surface; probably did not extend much down-
ward. Damage exposes medium to large air cells
throughout mastoid region, both above and below
ectotympanic tube. Preserved medial portion of ec-
totympanic tube bulges along its midline (as in StW
53d). Bulge ends in small, pointed, pseudostyloid
process. Stylomastoid foramen lies at anterior end of
moderately deep, m/l wide mastoid notch. Styloid
process is thin and lies very medial and somewhat
anterior to stylomastoid foramen, at medial extrem-
ity of low vaginal process. Carotid foramen would
have been even more medially placed. Superior sur-
face of petrosal moderately broad and relatively flat,
with very obliquely oriented, long, very low ridge
above region of superior semicircular canal. Below
medial edge of petrosal is a thin superior petrous
sinus. No trace of subarcuate fossa. Sub-subarcuate
fossa very broad. Sigmoid sinus very broad, and
shallow (as in StW 53f).stw 80
Includes StW 81, 82, and 83. L mandibular fragment
(80) was being restored at time of study, so only cast
was seen, and is associated with isolated tooth and
tooth fragments (81-3). All teeth very worn. RM3
(81), the only complete crown, is “twisted,” with large
wedge (protostylid?) lying between large buccal
hypoconid and protoconid. Protoconid apex quite
mesially and centrally placed on crown (makes cusp
appear to be wrapping around front of tooth). Meta-
conid is the tallest cusp; b/l compressed and peripher-
ally placed (cf. M2 of StW 327; see Volume 3 of this
series, forthcoming). Wrinkling in talonid basin. StW
82 is a lower molar fragment, uninformative. StW 83
is a broken LP1, duplicates P1 in StW 80 mandible
(e.g., in triangularity), and also compares well with
S tW 75 and 404 (see Volume 3).REFERENCES
~Clarke, R. J. 1994. The significance of the Swartkrans
Homo to the Homo erectus problem. Cour. Forschn.
Senckend. 171: 84-93.
Hughes, A. R. and P. V. Tobias. 1977. A fossil skull proba-
bly of the genus Homo from Sterkfontein, Transvaal.
Nature 265: 310.