OLDUVAI GORGE 197
Upper Dentition. An isolated LP1 matches RP1 in
maxilla. Both Pls subsquare teeth with rounded
lingual corners and tiny but distinct angulations at
parastylar and metastylar regions. Protocone is not
isolated as a cusp, but is incorporated into a broad,
sweeping crest that rings base of centrally positioned
paracone and arcs from parastylar to metastylar
regions. As seen on the L, P1 has two roots; its
occlusal surface, although worn, was not of high relief.
RP2 damaged buccally; was probably wider b/l than
P1. Protocone distinguished distally by groove; its
apex lies opposite the probably slightly distally
situated paracone apex. P1 and P2 occlusal surfaces
have some deep grooves. Mls are rather square teeth,
distended d/l by large hypocones and thick, slightly
curved postcingula. Thick postprotocrista runs to
metacone; mesially deflected preprotocrista was prob-
ably thick. Trigon basin was small, smaller than talon
basin. Lingual side of M1 somewhat sloping; buccal
cusps peripherally placed (buccal side thus straighter).
M2s slightly wider and longer than Mls. M2 lingual
and buccal sides slightly sloping; buccal cusps
somewhat compressed. M2 enamel surface deeply
grooved, and marginally cuspulated. Trigon basin
enclosed in a circle of crests (i.e., has divergent
protocristae and compressed buccal cusps). M2 talon
basin large, enclosed by postprotocrista and a thick
postcingulum that arcs distally and flows into a d/l
expanded, apically compressed hypocone. Impacted
M3s smaller than M~s, subequal to Mls. M3s with
highly cuspulated occlusal surfaces, these surfaces
essentially enclosed by a peripheral cresting system.
M3 narrower b/l distally than M2.
Lower Dentition. All teeth quite badly weathered
with some wear. Only L12 preserves crown. Judging
from roots, all Is were narrow. L12 with minimal
lingual curvature, no lingual swelling. Cs better
preserved on R, not highly worn (have not lost much
crown height); protrude noticeably above level of Ps.
In buccal outline, Cs have very short, almost
horizontal mesial edges, and longer, more sloping
distal edges. Crowns essentially parallel sided and
slender, lacking signs of cingulid or pillars buccally.
C lingual surface quite strongly oriented distally;
apparently had small mesial fovea and a broader distal
depression on either side of a very low central rise.
In cross-section, C lingual surface gently curved,
apparently with no heel. Margocristids defining
posterior foveae weakly developed.Ps low cusped (cusps not bulbous). Protoconid
and metaconid subequal in size, height; lie opposite
one another, mesial to midline of crown. P1 chunluly
wedge shaped in outline. P2 more square, with
rounded corners. On P1 is a small trigonid basin that
had been enclosed by tightly curved paracristid lying
high up on crown; talonid basin is moderate, sur-
rounded by stout crest. P2 trigonid basin smaller,
more centrally placed than on P1, and bounded medi-
ally by thick paracristid. Talonid basin somewhat
larger than on P1. Thick cristid distally surrounding
grooved P2 talonid basin.
On all Ms, lingual cusps peripherally placed; buc-
cal cusps only slightly less so. M1 best preserved on R.
Protoconid and metaconid lie opposite one another,
far forward on crown. Entoconid and hypoconid also
opposite one another; base of hypoconid is greatly ex-
tended across midline of crown to base of metaconid,
truncating base of entoconid. Wedge-shaped hypo-
conulid lies in midline of crown. Some deep grooving
of enamel surface of Ml crown. Small pit lies between
metaconid and protoconid, far back from mesial edge
of crown; another small pit lies in region of proto-
stylid. M1 apparently fairly long, although not nar-
row; rounded distally. RM2 was probably a little
longer m/d than M1; enamel slightly cuspulated.
As in Ml, small pit lies between bases of metaconid
and protoconid, well behind mesial margin. Base
of hypoconid extends only to midline of crown.
Hypoconulid slightly buccally displaced. M2 distal
margin smoothly rounded. M3 slightly longer m/d
again; surface highly cuspulated, obscuring cusp de-
tail. Trigonid basin large; intrudes between regions
of protoconid and metaconid; base of probable
hypoconid does not cross midline of crown. Apparent
hypoconulid quite buccally situated; lower region
between base of this cusp and entoconid appears as
low, subdivided, obliquely oriented ledge in d/l part of
tooth. M3 distal margin smoothly rounded.OH 21. Upper L molariform, unworn. Possibly
dm2, since longer m/d than b/l. Very divergent
protocristae; postprotocrista particularly well devel-
oped. Good anterior fovea and well-defined talonid
basin delineated by thick postcingulum and large
hypocone. Some lingual slope.OH 30. Various teeth and tooth fragments. Also
lots of tiny cranial fragments. Some teeth identified as
Ldcl, dml, and dm2. dc probably hominoid (not