ER 3883 Morph
KNM-ER 730. Includes mandibular symphysis and
L corpus, occipital lacking area of foramen magnum,
anterior fragment of L frontal, L posterior parietal
fragment including some of the sagittal suture, and L
maxillary fragment with tooth roots. Also some
isolated teeth.
ER 730A. Mandibular symphysis and L ramus.
Relatively broad but shallow jaw. Symphysis bears
slight subalveolar depression, some bulging around C
roots; shows slight retreat in profile. Inferior margin
slightly elevated anterior to mental foramen, which lies
under juncture between P2 and M1. Digastric fossae
quite broad and anteriorly well defined. Submandibular
fossae very shallow; superior internal plane slightly
convex. Root of ramus seen on the L; indicates that M3
would have been exposed in side view. Anterior teeth
represented by roots or alveoli only; were aligned
straight across at front of jaw. Is were tiny. C was
relatively large to judge by the root. Ps represented only
by roots. Anterior of two P1 roots also lies in line across
with anterior teeth. Preserved on the L, straight tooth
row diverged markedly behind P1. Ms worn flat; longer
m/d than broad b/l, but not extremely narrow.
ER 730B and D. Occipital (B) with part of L
parietal that articulates with it and preserves sagittal
suture; bone quite thick. Parietal-occipital profile
presents reasonably smooth curve. Profile descends
rather steeply to nuchal plane, which is delineated by
low, horizontal nuchal line. Nuchal line bears slight
elevation in midline that is inferiorly peaked into low,
triangular external occipital protuberance. Occipital
much broader than tall s/i. Lambdoid suture arcs from
side to side; it flattens a bit in region of lambda and is
regularly denticulated. Nuchal plane has shallow
scalloping on either side of midline but is otherwise
largely featureless. Occipitomastoid suture preserved
and runs quite vertically. Surface weathered; from
parietal fragment it appears that temporal lines were
not in evidence on the posterior part. Internal
occipital protuberance is broad; L transverse sinus is
deeper than R.
ER 730C. L lateral frontal fragment, including part
of L supraorbital margin. Very thick bone. In profile,
frontal rises behind a shallow sulcus; laterally it shows
a temporal line that clearly stayed low on side of skull.
Postglabellar plane shallow; frontal arcs up fairly
steeply behind. From above, supraorbital margin
retreats somewhat from glabella, then arcs back slightly
and forward again. Long, well-excavated notch in
inferior upper margin of orbit lies just medial to
mediosuperior corner of orbit; seen from above, notch
appears as very slight indentation. Superior margin of
supraorbital rim is preserved on the L; its anterior face
is flat, faces forward medially, but twists obliquely back
as it proceeds laterally until it faces largely upward
beyond midpoint of orbit. Superior margin of orbit
curves smoothly into orbital roof below. Top of L and
part of R frontal sinuses preserved; confined to region
of glabella.KNM-ER 3732. Very partial cranium lacking most
of the R side of the neurocranium, lower L face, lower
L parietal and occipital, and all of basicranium. Robust.
Cranial bone moderately thick. Bone surface very
eroded. Similar to ER 3883 in cranial profile, midline
depression in glabella region, vertical, flat backward-
facing posterior orbital wall, deeply incised temporal
fossa, configuration of supraorbital tori (including
lateral tapering), inferiorly bulging zygo-matic region,
and temporal lines (rise high up ante-riorly and fade
out posteriorly).
Region just behind and above glabella shallowly
concave. In profile, frontal rises gently from the some-
what long, shallowly concave posttoral plane to reach
its maximum height probably around bregma, then
curves gently down again. Superior orbital rim not
thick; would probably have flowed smoothly into roof
of orbit below. L orbital rim mostly preserved and
subsquare. Region of glabella was very broad and shal-
lowly indented in midline; stood out in front of orbital
rims in superior view. Frontal sinuses pervaded glabel-
lar region and extended lateral to it to an undeter-
minable extent. Interorbital region broad. Postorbital
constriction pronounced. L temporal line visible; it
runs up posterolateral edge of zygoma onto posterior
part of orbital rim, forming posterior border.
Squamosal region flowed smoothly into alisphenoid,
which did not flex markedly at its inferior extremity
(thus no distinct infratemporal fossa). Temporal fossa
well excavated from side to side; it was quite long,
with its anterior wall sloped forward. Anterior facial
surface of zygoma bulges anteriorly.
KNM-ER 3883. Slightly distorted but relatively
complete neurocranium, lacking most of facial
skeleton.
In profile, frontal rises smoothly from supraorbital
tori to reach its maximum height well back along