2 H o u K (I u D I AN ( C 1-1 o IT I< o u T I EN ) : Low E R C AV E 549
glabellar region. After the rise, profile turns back to
curve smoothly to its highest point (above auditory
meati), then descends gently beyond the very high-
placed lambda, to a point about midway along occipital
plane. From there, profile descends more steeply to a
moderately tall, posteriorly protruding bulge delineated
superiorly by a wide, shallow horizontal sulcus. Inferi-
orly, nuchal plane descends smoothly and steeply down
and forward from bulge. Seen from behind, skull is very
wide, relatively low. Greatest width is low down across
superiorly bulging mastoid processes. Sides of braincase
relatively straight; tilt in gently from processes; curve
broadly inward rather high up in region of temporal
lines, and slope toward raised midline bulge. Viewed
from above, skull tapers moderately strongly in to what
were probably quite marked postorbital constrictions.
Also as seen from above, region of mastoid bulge lies
just posterior to midpoint of braincase; ledge-like supra-
orbital tori apparently were oriented straight across from
side to side. From fiont supraorbital tori, although dam-
aged laterally, were not as wide as maximum skull width
further back Also from front, L supraorbital torus (the
less damaged) bears a wide, shallow, and quite far later-
ally situated supraorbital notch. As seen on the R,
supraorbital torus thickened laterally. Posttoral planes
are quite horizontal and long a/p, and become much
longer laterally (thus emphasizing low, vertical frontal
dome). Medially, posttoral planes descend gently into
steeper postglabellar planes. As seen on the L, orbital
roof is quite concave, flowing smoothly down and then
up onto toral surface. Interorbital region appears to have
been extremely broad. Broken ethmoid region was mul-
tifocular. A low midline keel runs from a somewhat
bulging bregmatic region and fades out at superior as-
pect of vertical part of frontal; part of the frontal suture
persists anterior to bregma. Keeling continues posterior
to bregma, about two-thirds of way along sagittal suture.
Faint temporal ridges emerge at posterior aspect of lat-
eral portion of supraorbital tori; run steeply up for a
short distance before turning smoothly back to descend
quite steeply above mastoid regions, then terminate in
broad swellings of parietal bone in region of asterion.
In Ill/L and D1, sagittal keeling and temporal
lines are much less pronounced. In I/L, bregmatic
swelling and frontal keeling more pronounced; tempo-
ral lines less visible on cast. I/E closest in keeling to
II/E. I/E most similar to II/L in frontal doming.
Frontal doming less pronounced in D1, III/L, and I/L
(thus smoother curve up frontal in profile). All speci-
mens have big parietal swelling at asterion. Brow
thinnest in I/E and thickest in lIl/L. Supraorbital tori
thicken laterally in III/L and l/L, and appear to re-
main uniformly thick laterally in D1 and I/E. Medial
portions of tori of III/L are flattened anteriorly. Post-
glabellar and posttoral planes longer a/p in D1 and
IWL, and shorter in I/L. To varying degrees, all speci-
mens have lower postglabellar than posttoral planes.
I/L and IIl/L have long, shallow, lateral supraorbital
notches separated by a downward bulge from shorter,
better defined medial supraorbital notches.
Viewed from above, glabella most protrusive in l/L
and somewhat so in D1 and III/L. In these three speci-
mens (viewed from above), profile is concave lateral to
glabella, with lateral portions of tori protruding anteri-
orly. In III/L, (broken) ethmoid multifocular. In l/E and
D1, apertures of R and L frontal sinuses are well sepa-
rated at midline. In III/L part of L zygoma is preserved;
contacts frontal. Frontal process thin at zygomati-
cofrontal suture; broadens significantly just below into a
flat surface that faces obliquely laterally. Medial margin
of zygoma curves inward quite strongly (suggests orbit
had been rather small and not rectangular). Superior
margin of orbit slopes gently downward laterally. “Malar
tubercle” posteriorly distended as a s/i tall flange extend-
ing over region of temporal fossa. Posterior wall of
zygoma faces almost directly posteriorly onto fossa.
Il/L shows (as better seen on L) a relatively a/p
long but relatively s/i low squamosal with an almost
horizontal superior margin. Squamosal suture ridges on
parietal are quite thick and pronounced. As seen on the
L, anterior squamosal suture corners moderately, with
some consequent partitioning of anterior and posterior
temporal fossae. Alisphenoid corners gently inward in-
feriorly, delineating a small infratemporal fossa. Parietal
notch relatively deep. Parietomastoid suture long and
horizontal. Posterior root of zygomatic arch (as seen on
L) originates just in front of the ovoid, vertically ori-
ented auditory meatus, and flows into a somewhat
shelf-like, upwardly oriented suprameatal crest. Crest
continues toward parietal notch as a pronounced but
more mound-like supramastoid crest. As also preserved
on the L, ectotympanic tube is somewhat thick walled
and strongly appressed to mastoid process; was proba-
bly well ossified laterally. Tube bears a low, thick vaginal
process that seems to have peaked around the styloid
process, and forms a very tall s/i, somewhat posteriorly
oriented, wall to the deep, somewhat m/l wide articular
fossa. Steep anterior wall of fossa is strongly arcuate
and very tall s/i, and seems to have flowed smoothly
onto a very truncated sphenotemporal surface. Fossa