KOOBJ FORA (INCLUDES EAST TURKANA, ILERET) 135
superior portions; they also flexed well below nasion,
although the initial angle of infra-nasion slope is not
determinable. L frontonasal suture is preserved below
what remains of nasal bones (indicates that nasals
would have been fairly long and that forward flexure
continued even as these bones increased substantially
in width toward their inferior ends). Nasals would also
have arced from side to side. Frontal processes of max-
illa fragmentary; preserved parts around nasal aperture
curve outward as they approach midline. Seen on the
L, a facial pillar continues from high up beside nasal
aperture to descend below inferior margin of nasal
aperture to region of C root. Height of nasal aperture
uncertain. Aperture was relatively narrow both superi-
orly and inferiorly; inferior corners did not expand
notably outward. Inferior margin of aperture not pre-
served; behind, there appears to have been a distinct
step down to the relatively flat nasal cavity floor.
Making the above-noted adjustments to the
existing reconstruction would produce a much more
vertical anterior plane of maxilla. Maxilla itself was
massive, very flat and broad across front, curving back-
ward only lateral to the C. Anterior root of zygomatic
arch takes origin quite close to (eroded) alveolar mar-
gin (its anterior surface above P1) and rapidly arcs lat-
erally. Zygomatic plane probably faced almost directly
forward, producing a lower face of remarkable flatness
lateral to the nasal region, with cheekbones shifted far
forward, almost to plane of nasoalveolar clivus. Pre-
served degree of lateral protrusion of anterior root of
zygomatic arch strongly implies that bizygomatic
breadth would have been very great (consistent with
great flare of suprameatal shelves at posterior roots of
zygomatic arches). Posterior surfaces of zygomas form
a flat plane angled anterolaterally and lack a sharp rim
enclosing temporal fossa. Maxillary sinus develop-
ment, as preserved on the R, was considerable laterally,
extending outward to zygomatic portion of maxilla. Si-
nuses did not descend close to roots of upper teeth; no
sign of their encroaching upon nasal cavity.
Anterior squamosal would have flowed smoothly
and continuously, into alisphenoid. Wall of temporal
fossa smooth above; inferior part of squamosal and
sphenoid form almost a right angle to this wall.
Squamosal was neither very long a/p nor very tall s/i;
suture was probably somewhat arcuate above. Sutural
configuration immediately posterior to this is impossi-
ble to determine; probably there was no parietal notch
or corner. Lambdoid suture rose relatively sharply
from asterion, appears not to have peaked at lambda.
Compared to height of skull, occiput was relatively
tall s/i and not very wide.
About half of R and a somewhat less of L audi-
tory meatus preserved; opening would have been very
large and rather circular. Posterior root of zygomatic
arch emerges from suprameatal torus and continues its
trajectory forward and laterally. Broad shelf of bone
would have existed between cranial wall and zygo-
matic arch. Posterior root of zygomatic arch envelops
medial half of meatus, producing a thick suprameatal
torus (not crest). Torus is slightly indented above
meatus and flows into a bulging mastoid. Articular
fossa broad, shallow, with considerable forward-
sloping extension but no articular eminence. Posterior
elevation corresponds to thick anterior wall of ecto-
tympanic tube. No posterior fissure or any other
discontinuity between fossa and wall of tube. Medial
articular eminence steep and thick.
Mastoid region badly damaged, so projection of
mastoid processes (if any) is impossible to deter-
mine. Breakage shows extensive pneumatization via
small air cells. Mastoid region is mound-like and
bulges quite far laterally, from probable area of oc-
cipitomastoid suture to auditory meatus. Breakage
makes certainty difficult, but the whole mastoid re-
gion appears to curve in quite sharply medially (sug-
gesting no significant projection in this region, nor
any vertical component on medial surface of
process). On the R, an enormous orifice situated far
forward and laterally may represent the mastoid
foramen. Preserved (if damaged) R petrosal is rather
short vertically but quite broad mediolaterally; only
a very low elevation exists in region of arcuate emi-
nence. Region of subarcuate fossa entirely flat and
filled in. No sign of superior petrous sinus. Sub-
subarcuate fossa short and deep.
Palate broken posteriorly, badly eroded along
alveolar surfaces. Sides appear to have curved inward
evenly from all sides, possibly reflecting splayed cheek
tooth roots. Palate deep only in center, with sloping
surfaces at front and sides. All I alveolae relatively
small, at least in cross section; were probably not very
long. In contrast, C roots would have been very stout
and much longer. Both P1 and 2 were double-rooted
with P2 roots separated further up. Ml and 2 were
three-rooted.
Internally, little is preserved of cranial vault detail.
A broad thickening representing the internal occipital
protuberance lies low down, as do traces of R trans-
verse sinus coursing laterally away from it.