ANT 3514- Introduction to Biological Anthropology
Plio-Pleistocene Hominids
Lab 9, Week of 10/27/03
The focus of this lab is gracile and robust Australopithecines and “early Homo”. As
such, we will be comparing specimens of the subfamily Australopithecinae with those of
the early members of the subfamily Homininae. The genus Homo emerges
approximately 2.4 m.y.a., and as we will see these fossils possess both ancestral and
derived morphological traits.
STATION 1 – Gracile vs. Robust “Australopithecines” (pgs. 213-216, 218, 228, and
245 in your textbook; check out Johanson in your reader)
This station focuses on the similarities and differences between the gracile and the robust
Australopithecines. At this station you will find:
 Composite cranium of Australopithecus afarensis
 2 crania of Paranthropus robustus (A6, A28)
 a mandible of Paranthropus boisei (“Peninj”)
 2 crania of P. boisei (KNM-ER 406 and OH 5)
 a cranium of Paranthropus aethiopicus (KNM-WT 17000 – “The Black Skull”)
The subfamily Australopithecinae (the Australopithecines) contains a gracile group and a
robust group, a clade-based distinction. These groups are differentiated based on
differences in their cranial morphology. (Their postcrania do not necessarily conform to
a “gracile vs. robust” distinction.)
(in class) Complete the following table comparing the crania of these different
australopithecines:
A. afarensis
P. robustus
P. boisei
P. aethiopicus
Cranial
cresting
(sagittal and
nuchal)
Degree of
Prognathism
Degree of
Post-Orbital
Constriction
Size of anterior
vs. posterior
teeth
Overall
Robusticity
(rank 1=most
robust, 4=least)
(at home) Based on the characters you observed in lab, do you see similarities
between certain species? Does it seem there are distinct groups represented in these
fossil species? If so, what are they?
(at home) What do the cranio-dental differences between the species noted above
suggest to you about the subsistence strategies of robust and gracile
Australopithecines?
STATION 2 – Australopith Mandibular Anatomy
(in class) Compare the mandibles of each species:
A. afarensis
P. boisei
Dental Arcade Shape
(rectangular vs. Ushaped vs. parabolic)
Canine Size (small vs.
large)
Presence/Absence of
Chin
Pan troglodytes
STATION 3 – Gracile Australopithecines and Homo
The focus of this station is to compare the differences between the gracile
australopithecines and Homo habilis. At this station you will find:

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a cranium of A. africanus (A73)
a cranium of Homo habilis (KNM-ER 1813)
H. habilis foot
femur of H. sp. (KNM-ER 1472)
articulated foot and a femur of a chimpanzee
human femur
H. sapiens
(in class) List any post-cranial features from the H. habilis foot and H. sp femur that
indicate bipedality. Use human and chimpanzee material for reference.
(in class) Complete the following table regarding the similarities and differences
between the H. habilis and A. africanus crania:
A. africanus
H. habilis
Cranial Vault Height
(short vs. tall)
Overall Robusticity
(most vs. least)
Degree of Prognathism
Shape of Face/ Zygomatics
(flared vs. non-flared; broad
vs. narrow; tall vs. short)
Dental Arcade Shape
(U-shaped vs. parabolic)
(at home) Can A. africanus conceivably be ancestral to H. habilis? Why or why not?
Include morphological (from the specimens) as well as temporal and geographic
elements in your answer. Reference boxes 6-2, 7-3, and 8-1 to support your answer.
STATION 4 Robust australopithecines and Homo
The focus of this station is to compare the crania of the robust australopithecines and
early Homo. At this station there is:
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crania of P. boisei (A27, A30)
a cranium of Homo habilis (OH 24)
a cranium of Homo rudolfensis (KNM-ER 1470)
(in class) List all significant differences between the crania of the robust
australopithecine to that of H. habilis and H. rudolfensis .
(in class) Compare the crania of H. habilis and H. rudolfensis. What differences are
apparent? What similarities are apparent?
(at home) Based on morphological and temporal comparisons, can P. boisei, or any
of the robusts be ancestral to genus Homo?
(at home) P. boisei males were roughly twice as large as females, while H. rudolfensis
males were only about 25% larger than females. How might social behavior differ
between these species? Why might it be different? Are there any modern primates
with which you could draw analogies?
Station 5 - Early Homo versus modern Homo sapiens
(in class) Compare the crania of these species and record the relative differences
revealed in your observations on the table below:
Homo rudolfensis
African Homo
Homo sapiens
erectus (H.
ergaster)
Supraorbital Torus
Degree of
Prognathism
Cranial Capacity
Morphology of Face
(Size and Shape)
Overall Shape of
Cranial Vault
HOMEWORK
The Hominid Family Tree up to H. erectus

Based on your comparisons above and in previous labs, sketch out a rough “family
tree” that includes all the australopithcines you know, as well as, early Homo and H.
erectus. Since there is no universal answer, be sure to defend your sketch with
insights and observations about derived traits, time scales, geographic location, etc.
that you learned in lab or in the text. A well-defended answer will receive full credit
even if there are a few errors. A time scale has been drawn to get you started.
1 mya
2 mya
3 mya
4 mya