140 A F R I c A
toral pro-file retreats gradually from glabella. Glabella
protruding, with slight depression in midline. Skull
widest across supramastoid regions. From behind, rel-
atively tall, straight side walls tilt in gently from later-
ally undistended supramastoid regions, turning in
strongly high up and continuing shallowly to midline.
Low, blunt, rounded juncture between occipital and
nuchal planes continues fully across occiput.
Double-arched supraorbital tori, continuous
across slight indentation at glabella in midline. In-
terorbital region broad. Supraorbital torus quite tall
s/i running outward and slightly upward from glabel-
lar region. From midline of orbit, torus diminishes in
thickness laterally due to descending profile of its up-
per border. Maximum toral thickness achieved well
behind anterior border at orbital midpoint, giving
torus sloping superior profile at this point. Vermicu-
late bone surface on tori. Orbital roof curves sharply
but continuously onto anterior surface of torus.
Judging by the L, frontal process of zygoma was
not very robust. A distinct ridge runs down its postero-
lateral margin, delineating a largely posteriorly facing
posterior surface. Margins of R orbit well preserved,
indicating subsquare shape with rounded corners.
Medially, inferior margin of orbit is defined by a sharp
crest that was probably originally confluent with
the preserved anterior lacrimal crest (lacrimal fossa
lay within orbit). Posterior lacrimal crest preserved in
part and indicates a fairly deep, quite long lacrimal
fossa. Anterior and posterior lacrimal crests essentially
parallel (did not close off fossa above).
It is not certain that any part of nasal bones is pre-
served; these would not have been very long or very
wide. Evidently there was some degree of nasal flexion
below nasion, as indicated below by the configuration
of the superior portion of the frontal process of the
maxilla on R. Nasal aperture was quite piriform and
not particularly tall or wide. Lateral crests of nasal aper-
ture sharp; externally they receded gently into broad,
shallow canine fossae. Inferior margin marked by a
small spinal crest starting at the midline and runs to the
nasal wall inside the lateral crest. No anterior nasal
some spines preserved; slight rise on either side of mid-
line suggests there may have been some development of
these structures. Traces of low, faint, horizontal conchal
crest lie low down just within nasal aperture. Floor of
nasal cavity stepped somewhat downward from inferior
nasal margin; exact nature of floor is impossible to
ascertain. Incisive fossae lie just behind putative ante-
rior nasal spines. Maxillary sinuses matrix filled; did not
encroach on nasal cavity. Nasoalveolar clivus fairly long;
arcs gently forward and is slightly curved from side to
side, with roots of anterior teeth detectable on its sur-
face. Anterior root of zygomatic arch rises fairly far
from alveolar margin; inferior border curves sharply
outward. Body ofzygoma faces almost directly forward.
Postorbital constriction moderately marked. Tem-
poral lines well marked, essentially ridge-like, running
behind supraorbital tori. Temporal lines visible (best
on R), arcing backward across parietal bone to recurve
onto temporal bone. Most of wall of temporal fossa is
missing on both sides. Part of L sphenotemporal su-
ture is preserved; it is not cornered or elevated. Nei-
ther zygomatic arch is preserved; extrapolation from
existing features suggests they would have been some-
what displaced laterally, indicating fairly wide but
short temporal fossae. There was probably no distinc-
tion between temporal and infratemporal fossae, al-
though the inferior portion of the L squamosal-and
presumably also of the alisphenoid-was oriented
quite horizontally. Articular fossa, preserved on the L,
is broad m/l and narrow a/p, relatively deep and
bounded in front by a distinct articular eminence; may
have been restricted behind by a postglenoid plate.
Medially, the fossa was confined, but not entirely
closed off, by very stout medial articular tubercle.
Auditory meatus large, perfectly circular, and
surmounted by a large, laterally projecting
suprameatal crest flowing into the laterally expand-
ing posterior root of the zygomatic arch. Supramas-
toid and suprameatal crests and superior margin of
posterior root of arch form a single long, prominent,
continuous structure. Forward of the posterior edge
of the meatus, this structure on its superior side
forms a broad, hollowed-out shelf that carries the
zygomatic arch quite far out from the cranial wall.
Ectotympanic tube is cylindrical and contacts mas-
toid process at its most posterior extremity. Mastoid
region bulges laterally. Small but distinct mastoid
processes bulge laterally and superiorly and are sepa-
rated from the true supramastoid crest above by a
shallow sulcus. Mastoid processes project slightly in-
feriorly and contribute to the formation of shallow
mastoid notches medially (best preserved on R).
Notch somewhat triangular, opening anteriorly;
bears distinct, somewhat concave digastric fossa be-
hind it. A broad, low, long crest forms the medial
side of the notch; it is longitudinally divided by a
sulcus (occipitomastoid suture?). Medial and parallel
to this putative occipitomastoid crest is a lower, less