Transcript Teeth / Diet

Continue on to Set # 16C
Teeth / Jaw
Diet
the lower jaw =
mandible
related term:
“mandibular torus”
The jaw . . .
in apes mandibles slant
outward and downward,
without a chin
(“prognathism”)
Pongid Prognathism.
(Line of greatest muscle force is shown in red.)
Understanding Physical Anthropology and Archaeology, 8th ed., p. 245
The jaw . . .
in humans lower jaw is
comparatively small, but
always has a distinct
chin
Modern human cranium.
Understanding Physical Anthropology and Archaeology, 9th ed., p. 432
The teeth . . .
apes have a “simian
shelf” rather than a chin
The teeth . . .
ape teeth have cusp
patterns for the lower
molars similar to those
of humans . . .
The teeth . . .
apes have a “Y-5” pattern
rather than a “plus-4”
pattern . . .
plus-4
Y-5
Y-5
The teeth . . .
apes (and monkeys) still
possess conical,
daggerish canines which
project well beyond the
surface of the opposite
teeth . . .
The teeth . . .
apes (and monkeys) have
diastemata, spaces
opposite the large
canine teeth . . .
(“diastemata” = plural of “diastema”)
The teeth . . .
diastema =
a space in the tooth row that
accommodates one or more
teeth from the opposite jaw
Teeth of a male patas monkey.
Understanding Physical Anthropology and Archaeology, 9th ed., p. 205
The teeth . . .
both apes and humans have
8 incisors
I
4 canines
8 premolars
12 molars
C
P
M
abbreviations
The teeth . . .
both apes and humans have
the same “dental formula”
2.1.2.3.
2.1.2.3.
Donald Johanson and Maitland Edey,
Lucy: The Beginnings of Humankind. NY: Simon & Schuster, 1981.
Dental formulae
Understanding Physical Anthropology and Archaeology, 9th ed., p. 120
The teeth . . .
apes have a “U”-shaped jaw
...
The teeth . . .
in humans the plate is
arched and curves
outward at the back
(parabolic arch) . . .
The teeth . . .
the overall evolutionary
trend is toward smaller
teeth
Continue on to Set # 16D
Next: Other Changes
Understanding Physical Anthropology and Archaeology, 9th ed., p. 136