NARIOKOTOME (WEST TURKANA) 181
not elevated. Temporal fossa thus smooth sided, with
no subcomponents. Fossa triangular in section, not very
capacious.
Articular fossae quite small, shallow. Articular
eminence in front is only modestly developed, fades
out medially. Very little development of medial artic-
ular tubercle. No evidence at all of postglenoid plate.
Ectotympanic tube quite short, though it appears to
be fully ossified laterally. Distinct vaginal crest peaks
at middle of tube, enveloping styloid process and
continuing laterally a bit. Styloid process fused to
base of skull. Stylomastoid foramen moderately
large, and lies somewhat lateral and posterior to sty-
loid process; it is the anterior terminus of a relatively
shallow, narrow mastoid notch. Area behind notch
flattish, smooth; no true digastric fossa.
Parietomastoid suture fairly long and relatively
horizontal. No anterior lambdoid suture. Parietal
notch quite well defined. Supramastoid crest swells out
posteriorly; is anteriorly confluent with more sharply
defined suprameatal crest. Posterior root of zygomatic
arch takes origin just in front of auditory meatus. Mea-
tus smallish, ovoid, inclined slightly backward on the
R and forward on the L. Mastoid processes small,
slender; would not have projected very far; damage at
tip reveals small air cells. On both sides mastoid
processes close to ectotympanic tubes although sepa-
rated by small fissures. Large swelling below supramas-
toid crest continues profile of mastoid process to a
level above the top of the auditory meatus.
Lambdoid sutures rise very gently from asterion;
probably did not peak at lambda. Occipital and nuchal
planes come together in a smooth curve; this area is
virtually featureless. Occiput wide; occipital plane is
quite short s/i. On the R is a well-defined but not tall
occipitomastoid crest that lies very posteriorly along
occipitomastoid suture. Carotid foramina face pos-
teromedially. Most of basiocciput preserved; relative
to plane of foramen magnum, it is noticeably flexed
upward. Basiocciput appears to have been relatively
narrow; its surface is flat. Compared to size of skull,
the roughly heart-shaped foramen magnum is quite
large. Anterior border of foramen lies just behind axis
of articular fossae. Margin of foramen magnum not
elevated at any point on its circumference. Occipital
condyles not salient and face mostly down, a bit later-
ally. Condyles also fairly flat, lacking any pronounced
anterior and posterior curvature. Posterior to foramen
magnum lies a small median occipital crest, with
anterior and posterior parts separated by a distinct
horizontal, rather flat plane. This produces a cruciate
pattern with slight scalloping between its “arms.”
Foramina ovale relatively small; they lie lateral to the
lateral pterygoid plates. Behind them, foramina ro-
tunda lie directly on sphenotemporal sutures.
Palate long, parallel sided, arcuate across front.
With eruption of M~s, still in their crypts, palate
would have been very long. Incisive foramen single,
long, large; its posterior extremity, including canal,
lies at level of anterior part of P1. Anterior slope of
palate extends beyond this point, although palate is
only moderately deep posteriorly, lacking steep lateral
walls.
Internally, region of arcuate eminence is narrow,
flat. Apparently there was no superior petrous sinus.
Region of subarcuate fossa flat. “Sub-subarcuate” fossa
short, deep. Internal occipital protuberance quite mas-
sive. Junction of superior sagittal sinus with the R
transverse sinus better defined than with the L.
All permanent upper teeth present except for M3s
and Cs. dcs still present. I1 crowns large, tall and
broadly spatulate; they are also quite procumbent,
although there is some very slight backward flexion
of crowns on the strongly procumbent roots. Lingual
surfaces were somewhat shoveled; enamel is fairly well
wrinkled. A tiny indentation in incisal edge, bilater-
ally, subdivides crown into smaller mesial and larger
distal components. 12s markedly smaller than 11s;
much less tall crowned, less spatulate. Lingual surfaces
more deeply shoveled. Like Ils, I2 incisal edges bear a
tiny indentation subdividing tooth. R and L dcs are
simple triangular teeth, with more or less symmetrical
crowns. RC has been removed. Although not fully de-
veloped, RC root very stout, with vertical groove on
both mesial and distal surfaces. RC crown relatively
small in proportion to root; not tall but quite broad.
Lacks lingual tubercle; lingual surface ringed by cin-
gulum. Mesial slope of crown slightly shorter than
distal slope. Both upper premolars have relatively
closed crowns. P1 has fairly a long buccal slope be-
cause protocone and paracone are more closely ap-
proximated. Both premolars have modest anterior
fovea and larger posterior fovea. On P2, postpro-
tocrista terminates buccally in a small, distinct style-
like structure.
Mls longer m/d buccally than lingually. Paracone
and metacone subequal. Thick preprotocrista runs
anteriorly around paracone; less distinct postpro-
tocrista runs directly to metacone. Oblique crease
delineates large hypocone from trigon. Talon basin