Cultural beginnings: Plio-Pleistocene archaeological occurrences

Cultural beginnings: Plio-Pleistocene
archaeological occurrences from the
Afar, Ethiopia
JOHN
W. K. H A R R I S
Abstract
In the time interval between approximately 2.5 million years and 1.5 million years ago and
against a background of changing environmental conditions and the emergence of highly
diversified populations of early hominids, the earliest archaeological occurrences have been
documented from a number of localities in the Rift Valley of East Africa. These have been
attributed to the Oldowan Industrial Complex. More recently, broadly comparable
archaeological occurrences have been discovered from Hadar and the Middle Awash located
in adjacent areas of the Afar, in Ethiopia. This paper summarizes the age, context and
characteristics of these occurrences and offers preliminary comments on their contribution to
greater understanding of early hominid adaptive patterns of behavior.
R6sum6
Les plus anciennes d6couvertes arch~ologiques document~es proviennent de la vallfe du Rift
en Afrique orientale, datant d'il y a entre 1,5 et 2,5 millions d'ann6es et se trouvant au sein
d'une p6riode d'6volution des milieux et d'apparition d'esp~ces tr6s diversifi6es d'hominides.
Ces dfcouvertes ont 6t6 attribufes au complexe industriel Oldowayen. Derni~rement, des
tbuilles dans l'Hadar et le moyen bassin de l'Awash, situ6s dans des terres adjacentes ~tl'Afar
en Ethiopie, ont mises ~ d6couvert de trouvailles g6n6ralement comparables. Le prdsent
article r6sume l'~ge, le contexte et les caractfristiques de ces dfcouvertes et prfsente des
commentaires pr6liminaires quant ~ leur r61e possible dans une comprehension approfondie
de m6thodes d'adaptation du comportement chez les anciens hominides.
There is a growing body of evidence to indicate that climatic fluctuations and relatively rapid
environmental changes occurred in the Great Rift Valley of eastern Africa during the time
:interval from approximately 2.5 myr (million years) to 1.5 myr. Studies of the geology,
geochemistry, palynology, and paleontology at important fossiliferous and artifact-bearing
localities in the Lake Turkana basin, for example, suggest that climatically induced
,ecological changes were probably the result of a reduction in rainfall (Bonnefille 1976; de
4
John W. K. Ilarris
Heinzelin etal. 1976; Eck 1976; Gentry 1976;Jaeger and Wesselman 1976; Cerling etal. 1977;
M. G. Leakey I980). Floral and faunal changes were reflected in the replacement of moisture
loving, closed forest and woodland savanna species by others adapted to drier and more open
bush and savanna grassland. At Olduvai Gorge, research indicates that environmental
changes were partly the result of palaeogeographical changes due to faulting as well as to
climatic changes from moister to drier and more arid conditions (Hay 1976; Bonnefille and
Riollet 1980). It is against this background of environmental transition that there appears in
the East African fossil record evidence for diversified populations of early hominids as well
as, in the form of stone artifacts, the earliest material manifestations of culturally elaborated
behavior.
Although there is only one hominid-bearing locality, the Shungura Formation, in the
Lower Omo Valley of Ethiopia, hominid populations were presumably widespread in East
Africa in the time period 2.5 to 2 myr (Howell and Coppens 1976). Moreover, various but as
yet unspecified selection pressures resulting in part from the environmental changes were
operating on hominid populations. These led to the differentiation and ultimately to the
speciation of the hominids, accounting for the presence of at least two and possibly three
species in the East African fossil record by about 2 million years ago. Figure 1 shows that
MYR
MYR
Z
O
o
MELKA KONTURE
KOOBI FORA
OLDUVAI
OLDUV~I
PENINJ
CHESOWONJA
KOOBIFORA
HOMO ERECTUS
I !
G
w
OLDUVAI?~
KOOBIFORA
OLDUVAI
KOOBI FORA?
OLDUVAI
KOOBLFORA
OMO
HOMO HABIUS
AUSTRALOPtTHECUS
AFRICANUS2
PAUCITY OF H O M I N I D FOSSILS
tN EAST AFRICA
II
AUSIRALOPIrHECUS
BOISEI
OMO
HADAR
LAETOLI
AUSTRALOPIIHECUS
AFARENSIS
MIDDLE AWASH
KANAPOI
LOTHAGAM
Figure 1 Early hominid species found in the fossil record of East Africa and the kinds
and timing of anatomical and behavioral changes that took place during the
Plio-Pleistocene.
Cultural beginnings
5
these species would include Homo habilis, which exhibits significant brain expansion
compared to earlier hominids, the robust australopithecine, Australopithecus boisei, and
perhaps a more gracile form, Australopithecus africanus (Howell 1978; Walker and Leakey
1978). The trend to brain expansion continues in the Homo lineage with the replacement of
Homo habilis by Homo erectus at 1.5 myr (R. E. F. Leakey 1976; Walker et al. 1982). By that
time, residual gracile australopithecine populations had become extinct, and although
examples ofAustralopithecus boisei still occur in the fossil record, this form too becomes extinct
by approximately 1 myr (Howell 1978).
It is in the same strata that yield evidence for highly diversified hominid populations that
the earliest archaeological occurrences have been recorded. Following large scale
excavations in Bed I and Bed II at Olduvai Gorge, the nature and character of these
occurrences were described and defined by Mary D. Leakey (1971). The artifact occurrences
recovered f?om Bed I became the type set of the Oldowan Industry, and in more recent years
similar occurrences have been documented and described, for example from the Omo, Koobi
Fora, Melka Konture and Chesowanja (Chavaillon 1976; Merrick 1976; Isaac 1976; Harris
1978; Chavaillon et al. 1979; Gowlett et al. 1981). Clearly, because of the widespread nature of
these early stone artifact occurrences, the Oldowan warrants full recognition as an Industrial
Complex (Bishop and Clark 1965; Clark et al. 1966).
Finally, the data available indicate that the inception of stone tool manufacture and use
closely coincides with the appearance of larger-brained hominid forms attributed to the
genus Homo (Isaac 1978; Harris 1980). Moreover, these simple stone artifacts should not be
viewed simply as evidence of a capacity for toolmaking; they also provide clues to a broad
range of adaptive behaviors on the part of some early hominid populations. Figure 1 shows
the timing of significant adaptive shifts in behavior as reflected in the archaeological and
fossil hominid record. Furthermore, as Isaac (1981 ) has pointed out, it is widely believed that
some of the innovative and adaptive behaviors that initiated the formation of the
archaeological record may also have been significant determinants in the trend towards
brain expansion. This paper summarizes the age, the context and the characteristics of
recently discovered archaeological occurrences fbund in the Plio-Pleistocene deposits at
Hadar and the Middle Awash, in Ethiopia, and offers preliminary comments on their
behavioral significance.
Hadar and the Middle Awash are situated close to the banks of the Awash River in
adjacent areas of the low-lying Afar Depression at the northeast terminus of the Ethiopian
Rift Valley. Figure 2 shows their location in relation to Plio-Pleistocene hominid and
archaeological sites found elsewhere in or on the flanks of the Rift Valley of eastern Africa.
Both study areas constitute a portion of the west central Afar sedimentary basin, which is a
N-S trending elongate sedimentary structure that runs parallel and adjacent to the Ethiopian
Western Escarpment (Taieb 1974; Taieb et al. 1976). In this trough-shaped depression
fluvial, deltaic, and lacustrine sediments accumulated, preserving a unique paleontological
and archaeological record for the late Cenozoic of eastern Africa (Johanson et al. 1982; Kalb,
Oswald et al. 1982; Clark et al. in prep.). The Plio-Pleistocene archaeological occurrences
reported here sample two separate time intervals during the sedimentary history of the west
central Afar basin. The age of the Hadar occurrences is estimated to lie between 2.4 myr
and 2.7 myr, whereas the earliest occurrences from the Middle Awash are approximately
1.3 myr to 1.5 myr.
6
John W. K. Harris
t
t
f
I
/
#
d
/,
J
I ;'-
MIDDLE
WASH
f
GULF
"7
AFAR
( ,7
,l!.
."
OF ADEN
""
: ~>'+"
"
"7
(
• b
I
..
t
J
"-,, .....:::~}i
,~,,+
Cry.. . . . .
,,
<:.:......
i
~!-
,:.,.!.:
/
ETHIOPIA
-:l
//
/
!j. ,.' :::.....
. .....
OMO
/
-~: 7,,,. i
4 ~
"~_ , " ,.. L a k e ~ ~, I
}:
7~'::.
:'-':~.i.
'~ --;'; %~:'i::.,H
• LOTHAGAM~
,
~::7,,~,:
dl~ S A M B U R U
:~ll~H I L L s
L a k e B a r i n g o ~._ " ,;~:"
•
~
,A,,.,,,,,,:~ ~;,~sdwX,,~A
,6 it . . . .
't "~ C H E M I = R O N I J
' ~ :. ' ,- •
KILdMBE.
~:~I~'TERNAN~.g"
.
.
LaKe,
-":~'7~.".~'t,~," ]
.:.,',,-.. ., ~ - .
Victoria
~b
.,:.t:
KARIANDUSI
'~ ~i
,=~.:'.:....
.
~.
..
.-
,< ,.
,Y. "';.~"~ ~t!;...':7.",. ~, K
.,.,,,4iPENINJ ~ J
-:::~GORGE~'"
~...~
'k ::"
r:':~;~ "."~.-: . . . . .
'~ T A N ' Z A N
IA
-7.: .~ '.,i':
:,~:" t .
M,p~
O
KM
I0(
Figure 2 Map of East Africa showing the location of Hadar and Middle Awash in
relation to other important Plio-Pleistocene early hominid and archaeological localities
found in the Rift Valley and surrounding terrain. (Modified after Johanson and Edey
]98l.)
Cultural beginnings
7
Hadar
Since 1973 multidisciplinary palaeoanthropological studies by the International Afar
Research Expedition at Hadar have contributed significantly towards a greater understanding of our zoological family, the Hominidae, during the Pliocene. Surveys undertaken in
sedimentary deposits of the Hadar Formation over four successive field seasons
(1973-1976/77) recovered abundant vertebrate fauna, including numerous well-preserved
hominid specimens and the oldest known stone artifacts (Johanson and Coppens 1976;
Johanson and Taieb 1976, 1978;Johanson etal. 1978, 1982; Corvinus and Roche 1976, 1980;
Roche and Tiercelin 1977, 1980; Harris and Johanson 1982; Harris in press). Geological,
paleontological and geophysical studies have established the stratigraphy and nomenclature
and provided a chronological and biostratigraphical framework for assessing the age of the
hominid and artifact finds (Taieb et al. 1976; Taieb and Tiercelin 1979; Gray et aI. 1980; Gray
1980; Aronson et al. 1977; Schmitt et al. 1980; Walter 1980; Walter and Aronson 1982).
Over 240 hominid specimens, representing a minimum of 35 individuals, have been
recovered from the Hadar Formation and these have been attributed to one taxon,
Australopithecus afarensis ~ohanson et al. 1978; Johanson and White 1979). Figure 3 shows
that, on the basis of the geochronology, the hominid fbssils span a time range of
approximately 3.0 myr to 3.5 myr. Palaeoenvironmental reconstruction indicates that the
early hominid localities sample low energy channel and floodplain lake margin depositional
environments situated in low-lying areas of an alluvial plain that was intermittently
inundated by lake waters (Taieb and Tiercelin 1979; Gray et al. 1980).
In contrast to the hominid finds, the early stone artifact localities come from higher up in
the stratigraphic sequence and are thus younger in age. Furthermore, the nature of their
geological context indicates past depositional environments associated with high energy
streams located on the alluvial plain between the plateau and the lake margin. Figure 3
shows their age to lie between approximately 2.4 myr and 2.7 myr. Stone artifacts of this
great antiquity were first discovered by Gudren Corvinus to the west of the main
hominid-bearing localities in an area where downcutting by the Gona River is today
exposing sections of the upper beds of the Hadar Formation (Corvinus 1976; Corvinus and
Roche 1976; Taieb and Tiercelin 1979). Evidence for the age, the nature of the geological
contexts and the characteristics of the Gona River archaeological occurrences are discussed
below.
Stratigraphy and dating
The sequence of Plio-Pleistocene sediments of the Hadar Formation so far studied extends
over an area of 65 square kilometers. This sequence is well exposed today in badtand
topography as a result of dissection by the Awash River and its tributaries. The Hadar
Formation has an aggregate thickness of 280 meters and, due to the presence of laterally
extensive marker beds (mainly volcanic tufts), has been subdivided into fbur stratigraphic
members: the Basal Member, the Sidi Hakoma Member, the Denan Dora Member and the
Kada Hadar Member (Taieb et al. 1976). The sediments comprise lacustrine, lake margin
and associated fluvial deposits related to an extensive Plio-Pleistocene lake that periodically
fluctuated and inundated the entire sedimentary basin.
8
.John I4/. K. Harris
KADA G O N A
WEST
EAST
280-
KADA
HADAR
OUNDA
HADAR
kST-3 "v~BKT-32(;T?y
,sT-2~...vv~
i ~ i " 2.Tmy(FT)~v~
kST-l; 4 - ........
w - -
27my (FT)
BKT-2 2.9my (K/At)
KH
I
,-e,,-,
~
CC
~
CC"""
200-~
DD3
vv i
.:~
w -
BKT-I
~CC
DD
"~
vv~
vv,~v~TT
........
®
vv~.
.......
I
OURDA
~tKMB3.Troy" ~
g~
(KIAr}
v v - - ~ZjT I
gg
100
',,
~ ] COBBLE
CONGLOMERATE
~
SANDS
KADADA MOUMOU
r - - ' l BASALT
vv TEPHRA
gg OASTROPODS
~® OSTRACODS
A IN SITU ARTIFACT
OCCURRENCES
O HOMtNID
LOCAUTIES
40 my(FT)vv~--
gg
)SH3
:~
;HT
2
SH
OUDALEITA
\~SHT " ~
:"~'"
©/
'~
vv_. I
ggl
""v
gg
BM
J.
Figure 3 Correlated sections of the Hadar Formation showing the stratigraphical and
chronological relationships of the Pliocene hominid and artifact sites. (Modified after
Taieb et al. 1978; Walter 1980.)
Cultural beginnings
9
The stone artifacts were discovered stratified in fluvial deposits belonging to the upper
beds of the Kada Hadar Member (KH) exposed along the banks of the Gona River and in the
badland topography to the west of the river. The most informative archaeological localities
are situated approximately 8 km upstream from the confluence with the Awash River where
a welt-exposed stratified sequence of coarse gravel and cobble conglomeratic deposits
interbedded with finer-grained sands, silts and tephra deposits reached an aggregate
thickness of 30 to 40 m. The stone artifacts were found in derived channel contexts and in
their lateral fine-grained silty floodplain equivalents (Roche and Tiercelin 1980; Harris and
Johanson 1982; Harris in press).
Figure 3 illustrates the stratigraphic relationships of the artifact-bearing conglomerates
and silts to the AST-1, AST-2, and AST-3 tephra horizons in the Gona River section. In
particular, the AST-2 tephra has proved to be an important stratigraphic marker for
correlation and also a crucial horizon for determining the age of the artifacts. It has been
correlated in the field and by feldspar chemistries to the BKT-2 tephra. These identifications
have been one of the principal means of correlating the Gona River section and sediments of
the Kada Hadar member exposed to the east in the Sidi Hakoma and Kada Hadar
tributaries (Taieb et al. t 978; Walter 1980). In the initial publications (Roche and Tiercelin
1977, 1980) the estimate for the age of the artifacts was based on potassium argon and fission
track age determinations on the BKT-2 tephra, the correlative of AST-2, which yielded dates
of 2.6 -+ 0.23 myr and 2.58 + 0.23 myr respectively (Aronson et al. 1977). These dates have
been revised and more recent K-Ar age determinations show the BKT-2 tephra to be
2.88 + 0.2 myr (Walter and Aronson 1982). The reliability of this new date is corroborated
by a fission track age determination of 2.7 + 0.22 myr on the AST-2 tephra that is within the
range of uncertainty of the K-Ar age (Walter 1980). Taken together these dates set important
new maximum limits on the age of the artifacts.
The palaeomagnetic polarity data collected from the Hadar Formation, when calibrated
against the absolute age determinations on the tephra horizons, show that the upper beds of
the Kada Hadar Member belong within the Gauss normal epoch following the short Kaena
reversed event, and thus have an age of between 2.4 myr and 2.8 myr (Aronson et aI. 1977;
Schmitt et al. 1980). The minimum age limit is in concordance with a new fission track date
on the BKT-3 tephra outcropping near the top of the Kada Hadar Member, which yielded
an age of 2.4 + 0 . 4 m y r (Walter 1980). Therefore, on the basis of absolute age
determinations, the palaeomagnetic stratigraphy and stratigraphic correlation, the Gona
stone artifacts range in age between approximately 2.4 myr and 2.7 myr, and are
substantially older than the earliest archaeological occurrences fbund elsewhere in the Rift
Valley of eastern Africa. The earliest artifacts reported from Member E and Member F in the
Shungura Formation at the Omo River are of the order of 2.1 myr (Chavaitlon 1976; Merrick
1976). Further to the south, the earliest artifacts found in the Lower Member of the Koobi
Fora Formation east of Lake Turkana and in Bed I at Olduvai Gorge are dated to t.8 myr
(Drake et al. 1980; McDougall et al. 1980; Curtis and Hay 1972).
The sites: context and assemblage characteristics
Archaeological studies at Hadar leading to tile recovery of Pliocene age stone artifacts were
initiated by Corvinus in 1973 and 1974. Much of this earlier work, however, was
ACHEOLEA. O"AVE'S
,~
|
~
"OM,'.,O LOC,.L,T,ES
PLIO-PLEISTOCENESERIES
% %
•
GEOLOG,CAL SECTIONS
ARCHAEOLOGICALSITES
Figure 4 Map of Hadar study area showing the Pliocene archaeological sites and hominid localities. (Modified after Taieb et al. 1978.)
PRESENT-DAYSURFIC|ALDEPOSITS
~
Cultural beginnings
11
concentrated on surveying the extensive fluvial gravels and sands that uncomformably
mantle the Plio-Pleistocene Hadar Formation (Taieb et al. 1976). These surveys and small
scale excavations undertaken principally along the banks of the Sidi Hakoma and Kada
Hadar tributaries produced biface and flake occurrences found in derived channel contexts.
The artifact occurrences are classified as Acheutian due to the diagnostic bifacial artifact
forms present. They are of Middle Pleistocene age (Corvinus 1975, 1976; Corvinus and
Roche 1976, 1980). In 1974, the archaeological survey was extended west to include
sedimentary exposures in the Gona River drainage. At one locality, Afaredo I (renamed
Kada Gona t), several whole flakes made ofbasatt were discovered and are reported to be
derived from a calcareous tuffaceous silt within the upper beds of the Hadar Formation
(Corvinus 1976). No excavation was undertaken; however, in light of this important
discovery, the survey was continued by H~l~ne Roche in 1976 and by the author in 1977 and
several new occurrences of stone artifacts were found near the Gona River. Figure 4 shows
the location of the Kada Gona 2-3-4 site and the West Gona site in well-exposed fluvial
deposits of the Kada Hadar Member, which are several kilometers downstream to the south
of the Afaredo site.
Kada Gona 2-3-4 site
The investigation of this site was undertaken by Roche and Tiercelin in 1976. Short reports
were published on the stone artifacts, which were recovered from two stratigraphic levels in
the local sedimentary sequence on the east bank of the Gona River: the middle conglomerate
and the upper conglomerate (Roche and Tiercelin 1977, 1980). In the stratigraphic interval
between the middle and upper conglomerates, there are interbedded deposits of clays, sands,
silts and the AST-2 tephra horizon. The in situ stone artifacts were found dispersed in
secondarily derived contexts. The presence of large clasts the size of cobbles and the massive
thickness of the conglomerates illustrate the high energy nature of the stream channel
deposits. These features of the depositional environments, when taken together with the
abraded physical condition of the stone artifacts, indicate transported and redeposited
materials. The 16 trachyte and basalt artifacts recovered in situ from the middle
conglomerate comprise both unifacially and bifacially flaked cobbles (chopper cores), cores
(including polyhedrons) and whole flakes. On a sample often cores the dimensions ranged in
size from 113 mm/80 mm/4t mm for the largest specimen and 71 mm/53 mm/42 mm fbr the
smallest. The whole flakes measured from 119 mm/63 mm/33 mm to 39.5 mm/34.5 mm/
11 mm in length, breadth and thickness. In addition, five cores were derived from the upper
conglomerate. Although the sample is small, the Kada Gona 2-3-4 stone artifacts are
classified as belonging to the Oldowan Industrial Complex on morphological/typological
and technological grounds as well as by the size range of the cores and flakes. They are
comparable to the stone assemblages recovered from Bed I at Olduvai Gorge, described by
M. D. Leakey (1971), and from the Lower and Upper Members of the Koobi Fora
Formation, east of Lake Turkana, described by Isaac (1976) and Harris (1978). From a
behavioral point of view, the stone artifacts provide important evidence for the tool making
capacities of early hominids living on the surrounding terrain. Furthermore, the geological
evidence shows that local streams during periods of high energy flow were transporting clasts
of cobble size in their bed load. The cobbles were being deposited and incorporated in
12
John I47.K. Harris
conglomerates that were presumably at times exposed, oft~ring a readily available and
important source of raw material.
West Gona site
The site was discovered in badland deposits of the Kada Hadar Member found outcropping
west of the Gona River during archaeological survey and geological reconnaissance by
"~.
%
LOCALITY 1
•
100 m-t-
,P
I. i
A.~RCHAEOLOGICAL
"~LOCALITY
i"
G, li2
i"
i
m"
+105m
I
C
L
A
Y
~ ~ ~'.: •
"
0
i ETHIOPIA
5
S
GT3
\
Y
N
meters
SECTIONS: WEST GONA SITE
G.T. 1
G.I~ 2
~2me.i~
,105m.
~
31m.
G.T,3
LEGEND
Excavation
SANDS(S) CS= Coarse Sands
FS= Fine Sands
concretion
-102m.
-1Olin.
SILTS(Z) eg SZ= Sandy Silt
+
CLAYS(C) eg ZC= Silty Clay
•+÷,
I03 m.
,IOOm,
-~
+
•
COBBLE CONGLOMERATE
~2m
+
104m.
see Figure 6
PRESENT-DAY SAND RUNNEL
GEOLOGICAL TRENCH
ZC
Z L-'2-~
Z
SZ
~
SZ
SURFACE STONE ARTIFACTS
SURFACE FOSSIL FAUNA
SZ
FS
SC
ZC
CC
Figure 5 a) West Gona archaeological site plan.
b) West Gona local site stratigraphy.
EXCAVATED AREA
Cultural beginnings
13
Harris and Taieb in January 1977 (Fig. 4). T w o concentrations consisting of stone artifacts
and fossilized bone were found on the surface, and a small test excavation revealed a low
density archaeological occurrence stratified in fine-grained silt floodplain deposits. These
stone artifact and bone occurrences represent real anomalies in the distribution pattern of
archaeological traces of hominid activities across the landscape because, but for one or two
small concentrations found elsewhere, over the rest of the surveyed area stone artifacts are
missing and the sediments are generally poorly fossiliferous. Preliminary field correlation
shows that the site stratigraphically overlies the middle conglomerate and the 2.7 + 0.2 myr
AST-2 tephra exposed in the main Gona river section (see Fig. 3). It was possible to trace the
beds in the field and no major unconformities were observed between the two areas. A
preliminary date of 2.4 million years is therefore suggested for the West Gona artifacts based
on the minimum age for the Kada Hadar Member (Aronson et al. 1977; Schmitt et al. 1980).
~
SILTYCLAY
~
SANDYSILT
FINESANDS
~
COARSESANDS
wt CROSSBEDDING
COBBLE
CONGLOMERATE
~
• CHOPPER/CORE
dlh COREFRAGMENT
A FLAKE
•
FLAKEFRAGMENT
X BONESPECIMEN
o
meters
SANDYCLAY
~SILT
-'"
"';-"
"';.-" '::'.
¢
30 cn~ I
2Oc~|
~Ocrr,OC~I A
sj
;-~.
O
O L1
"'~
XlA
••
•
x
"',,
•
× "
~•
• --"~" A
J-30 ran
r2o cm
-lo<m
BLoc=
Figure 6 Isometric diagram showing the stratigraphy of the excavated area, the
horizontal and vertical provenance of the stone artifacts and the fragmentary bone
recovered from the West Gona archaeological site. The open stone artifact symbols
indicate surface finds.
14
John W. K. Harris
This would make them younger than the earliest artifacts found on the east bank; more
precise stratigraphic relationships must await further detailed geological mapping.
Figure 5a shows the site plan and Figure 5b summarizes the local stratigraphic sequence.
Figure 6 shows that the in situ stone artifacts and fragmentary bone occur as a low density
concentration scattered within a 20 to 30 cm lens of sandy silt. The archaeological occurrence
appears to be in primary context. The low energy nature of the sedimentary environment of
deposition as well as lack of size sorting or preferred orientation and the fresh condition of the
stone artifacts suggest that the archaeological occurrence was minimally disturbed during
site formation and by subsequent burial processes.
Preliminary palaeogeographical reconstruction shows that in the lower part of the section
there is evidence for high energy stream activity. On the basis of the upward-fining fluvial
sequence, it would appear that the stream migrated laterally away from the locality, and
fine-grained sands and silts were deposited in a low" energy floodplain environment. The
archaeological occurrence provides evidence for hominid activities located on a stream bank
or adjacent floodplain subject to seasonal flooding. The onset of ponded and marshy
conditions is shown by the deposition of massive beds of clays containing root casts capping
the sequence. No artifacts were found in the clays; such environments were probably less
suitable for hominid occupation.
The surface stone artifacts were concentrated in two low density patches near the base of
eroded exposures of the K a d a H a d a r Member. A small test excavation (Fig. 7) measuring
10 m 2 located at the southern end of the outcrop (Locality 2) yielded 19 stone artifacts and
five bone fragments. This low density scatter was concentrated vertically over 10-15 cm
Figure 7 The excavation at locality 2, West Gona archaeological site with the Gona
River in tile background, at Hadar.
Cultural beginnings
15
within a lens of sandy silt (SZ). The areal boundaries of the occurrence were not defined. A
chopper/core found in the same lithologic horizon of a geological trench at the edge of the
excavation indicates that the archaeological horizon extends laterally further to the west.
Table t shows the composition of the stone assemblage, which comprises two basic classes
of artifact forms: flaked cobbles and whole and fragmentary broken flakes (Fig. 8: 1,2). The
flaked cobbles are small ( < 100 mm) and the presence of several generations of flake scars
testifies to core reduction sequences. The extremities or edges are sharp and there is no
evidence for blunting or abrasion to suggest their utilization as implements or 'tools'. For this
reason the flaked cobbles are classified as 'cores' (sensu stricto) rather than being placed in a
chopper 'tool' category following the typological system devised by M. D. Leakey (1971).
The whole flakes and flake fragments exhibit noticeable striking platforms and pronounced
bulbs of percussion. A number of the flakes have cortical dorsal surfaces, possibly suggesting
that some flaking was done by hominids at the site. Both trachyte and basalt were used for
stone artifact manufacture. Although no unmodified cobbles or 'manuports' were found in
the excavated occurrence, a readily available source of raw material was probably close at
hand. A m a x i m u m dimension of 100 m m was measured on basalt cobbles incorporated in
the basal conglomeratic horizon at the site; this provides an index of the size of clast
transported in the bed load of the local streams and corresponds to that of the flaked cobbles
found at the site. It is likely then, that cobbles of a similar size were available for artifact
manufacture in nearby conglomerates at the time of hominid occupation.
Table 1 West Gona archaeological site.
SURFACE
Location 1 Location 2
Core (chopper)
Whole flakes
Flake fragments
Core fragments
TOTAL
Bone fragments
Location 2
2
6
7
1
-5
4
5
1
5
12
1
16
14
19
7
3
5
EXCAVATED
range of maximum mean
dimension (mm) (mm)
95-84
72-26
51-14
81
90
42
33
T h e faunal remains are ti'agmentary and only one specimen is identifiable to taxon: a small
piece of the plate of an elephant molar. The co-occurrence of stone artifacts and bone appears
to be more than a fortuitous association. The low energy environment of deposition in
addition to the fresh condition of the stone artifacts and the lack of size sorting (specimens
range in m a x i m u m dimension from 84 m m - 1 4 mm) suggest that the occurrence was the
result of hominid activities rather than an accumulation concentrated by fluvial processes.
This has an important bearing on a range of questions related to the diet and subsistence
activities of Pliocene hominids, which will be fully explored in future site investigations.
The artifact sample from the West Gona site is indistinguishable in terms of morphological
and technological characteristics from the artifacts recovered from the K a d a Gona 2-3-4 site.
T h e presence of pieces of smaller size in the whole flake and flake fragment categories of the
16
John W. K. Harris
Figure 8
1. ~Core' (chopper) from the West Gona archaeological site, Hadar. Note the
presence of several generations of flake scars indicating that the *core' has
been considerably reduced.
2. Sample of the excavated occurrence of whole flakes from the West Gona
archaeological site, Hadar.
Cultural beginnings
17
West Gona assemblage is presumably due to the relatively undisturbed sedimentary context.
Overall both assemblages show clear affinities to the artifact occurrences found in Olduvai
Gorge Bed 1 and the Koobi Fora Formation, east of Lake Turkana, attributed to the
Oldowan Industrial Complex (M. D. Leakey 1971; Isaac 1976; Harris 1978). One class of
artifact, retouched or trimmed pieces, is clearly missing, perhaps due to sampling error. The
Gona River artifacts contrast with the artifacts recovered from Member F of the Shungura
Formation at the Omo River mainly as a consequence of differences in raw materials
(Chavaillon 1976; Merrick and Merrick 1976). The Omo artifacts were made on quartz,
which shatters on impact and produces large numbers of small angular pieces. As a result,
the greater proportion of these assemblages consists of very small flakes and angular
fragments which are of limited value for comparative purposes.
Middle Awash
Systematic archaeological survey of the Middle Awash was undertaken in 1981 as part of a
multidisciplinary palaeoanthropological investigation coordinated byJ. D. Clark and T. D.
White. The study area is located along the center of the Awash River valley, south of Hadar
and north of the town of Gewani (Fig. 2). Extensive deposits of Miocene, Pliocene and
Pleistocene sediments are found outcropping along the eastern and the western Awash
Valley margins as well as in the basin center. These proved to be richly fossiliferous
(including hominids) and contain a virtually uninterrupted paleontological record over the
last six million years. FossiIiferous deposits of Pleistocene age are particularly well exposed
east of the present-day Awash River, which bisects the study area. Survey of this area located
numerous archaeological occurrences that provide evidence for hominid occupation over the
last 1.5 million years (Clark et al. in prep.).
Figure 9 shows the location of Early Pleistocene Oldowan and Middle Pleistocene
Acheulian occurrences. These were discovered in laterally extensive deposits of fluvial
sediments between Meadura and Matabaietu. To the north of Meadura, concentrations of
Middle Stone Age and Later Stone Age materials were found in late Pleistocene and
Holocene sediments. In addition, early Acheulian artifacts were discovered during a brief
survey of Pleistocene deposits on the west side of the Awash River, demonstrating that area's
potential and thus high priority for further large scale survey. In this section, discussion will
center on a description of the Oldowan occurrences, the earliest archaeological traces of
hominid occupation in the Middle Awash. Preliminary reports on the overall results of the
1981 palaeoanthropological investigations are in preparation and will be published
elsewhere (Clark et al. in prep.).
M. Taieb (1974) was the first to realize the palaeoanthropological significance of the
Middle Awash during geologic reconnaissance in the late 1960's. In 1971, he guided a group
from the Pan African Congress to exposures containing early stone artifacts north of Gewani
(Abebe et al. 1976). Small scale exploratory studies of the Middle Awash archaeology were
subsequently undertaken by J. Kalb and a Southern Methodist University group
coordinated by F. Wendorffor short periods between 1975 and 1978 (Kalb 1978; Kalb, Jolly
et al. 1982). A diverse group of archaeological occurrences was discovered including one
described from Matabaietu containing Oldowan type artifacts with a suggested age of 2 myr
(Larson 1977). The occurrence consisted of heavily patinated finds that were not in situ and,
18
John Pr; K. Harris
LEGEND
i
X
" ~ ~
MEADURA
}
type occurrence
[~] Oldowan
(test excavation)
type occurrence
[~ Oldowan
(surface)
'
[ ~ Acheution occurrence
(test excavation)
f',
[ ~ Acheulian occurrence
(surface)
HAR A 6
Surface artifact occurrence
I~ (provenience unknawn)
HAR A 2
~
Hominid locality
~Area
boundary
I
~Ephemeral sand channel
L
~
DAWAITOLI
[1~ Awa sh River
0
/
°
IIIIIIIII
BODO
-
0
" BOD A5
miles
3
kilometers
.5
-----------,~BOD A 2
~. BOD A 3
BOD A 1
- _~
l
GAMEDAH "
-
THE
MIDDLE
AWASH
""
"t
East Side
Central Sector
....
s,"
IETU
~"""""~
~:i:!:.
N
.... !ii~il :i ,,
.J"J A DDLE~
'--- . . . . . .
"~
BELOHDELIE
M"" ~.~>!~:i!:~i:.:~.
i~:-i:;~
Hi~-"'.
""
WEE-EE
/
MAP
LOCATION
Figure 9 Lower and Middle Pleistocene archaeological sites located east of the Awash
River in the central part of the Middle Awash study area.
Cultural beginnings
19
as is explained below, the designation of Matabaietu as an Oldowan locality remains
problematic. During survey in 1981, the earliest stratified occurrences of Oldowan artifacts
were found in previously undiscovered localities in the Bodo drainage. In the time available,
several surface samples of stone artifacts were identified, plotted, lifted and removed to the
National Museum of Ethiopia in Addis Ababa for study. One small excavation was
undertaken that yielded stone artifacts together with fragmentary fauna in a fine-grained
sedimentary context. As the study of the artifacts is still in progress, only brief preliminary
comments are offered on the stratigraphy and age of the occurrences, their context, and
morphological/typological characteristics.
The geological sequence comprises thick fluvial, deltaic and lacustrine sediments
intercalated with volcanic tuffaceous horizons that accumulated in the basin over the last 6
million years. A recently published geological summary of the Middle Awash deposits forms
a basis for describing the stratigraphical provenience of the earliest stone artifact occurrences
(Kalb, Oswald et al. 1982). These are found in the early Pleistocene 'Middle Bodo' beds. As
yet no artifacts have been recovered from the Pliocene 'Lower Bodo' beds or outcrops of
equivalent age surveyed from Wee-ee to Meadura.
Figure 9 shows the locations of Oldowan occurrences being exposed today along the
eroded margins of ephemeral streams in the Bodo area. The localities are clustered in two
fault-bounded blocks of sediment that are informally called the 'Middle Bodo' beds following
Kalb, Oswald et al. (1982). The northern block contains diagnostic suids, equids, and bovids,
which indicate an age of 1.3 myr to 1.5 myr (White pers. comm.; Clark et al. in prep.). Stone
artifacts and fragmentary fossilized fauna occur stratified together in river sands and gravels
in the northern block. These elements are found in lateral silty bank and overbank deposits,
some of which, in the southern block, overlie a grey vitric tuff. The stratigraphic relationships
of the northern and southern archaeological occurrences at Bodo remain to be worked out in
detail and geochronologic work by R. Walter on the volcanic units is in progress.
The most informative site, designated BOD-A3, is situated in the southern block near the
headwaters of the Ounda Bodo catchment. Nearly 400 stone artifacts and numerous
fragmentary faunal remains were found in relatively fresh condition scattered over a
steep-sided outcrop of fine-grained fluvial deposits. Table 2 shows that surface artifacts
include several flake scraper forms as well as modified and utilized flakes and cobbles,
including hammerstones. The major proportion of the assemblage consists of cores,
unmodified flakes and flaking debitage. A further 45 stone specimens were recovered in situ
from a 10 m 2 excavation. Basalt was the preferred raw material but artifacts were also made
of rhyolite, ignimbrite and chert.
The great majority of faunal specimens are highly fragmentary and the long bone
fragments occasionally display longitudinal and spiral fractures (R. Blumenschine pers.
comm.). No cutmarks have been found. Up to six species are present including several
bovids, an equid, an elephant, and possibly a hippo. Most specimens derive from a large
bovid species which, unlike the other taxa, is well represented by most classes of skeletal
parts. The fresh condition, lack of size sorting, lack of preferred orientation and sedimentary
context of the specimens indicate a low energy environment of silty river overbank
deposition. This suggests an archaeological occurrence in primary context or, at most,
minimally disturbed.
Several similar archaeological occurrences were found nearby in overbank silty deposits.
20
John W. K. Harris
Close to one of these, designated BOD-A4, clay samples were collected from a cone-shaped,
reddish discolored area. Analysis by M. Barbetti of the University of Sidney Radiocarbon
Laboratory showed that the samples were baked in antiquity. In recent years, the question of
the antiquity of hominid control of fire in Africa has been reopened with reports of baked clay
within archaeological horizons at Koobi Fora, Chesowanja and Gadeb (Barbetti et al. 1978,
1980; Gowlett et al. 1981). In view of the controversial nature of this evidence and due to the
fact that these localized discolored areas are widespread phenomena in the Middle Awash,
further detailed excavation, sectioning, and sampling will be undertaken at BOD-A4 and
elsewhere in an effort to determine the agencies that caused them to be baked.
Table 2 Middle Awash archaeological sites.
BODA3
Surface Excav.
Scraper
Discoid
Sub-spheroid
Miscellaneous
Mod. flakes, frags.
Mod. cobble
Hammerstone
Flakes
Flake frags.
Cores
Core frags./chunk
Cobbles
5
1
BODA5
Surface Excav.
HARA6
Surface Excav.
3
1
4
6
3
3
2
187
127
30
27
1
24
17
2
2
n = 389 n = 45
25
9
17
4
34
17
7
n = 65
n = 60
1
In contrast to the Oldowan finds in fine-grained depositional environments, two artifact
occurrences in fluvial sands and gravels were located near the banks of the K a d a Bodo
(northern block). One of these, BOD-A5, yielded 70 artifacts including a variety of subtypes
ofsmalt cores, several small retouched flakes, unmodified whole flakes and fragments (Fig.
10). Several specimens were observed in situ in a well-exposed, carbonate cemented
sandstone.
The stone artifact occurrences sampled at Bodo show morphological and technological
features in common with those stone assemblages recovered from Olduvai Bed 1 and from
the KBS T u f f unit at Koobi Fora, which were classified under a typological system devised
by M. D. Leakey (t 971 ). The diminutive and exhausted nature of the flaked cobbles suggest
that the Middle Awash 'tools' represent the by-products of least-effort solutions to the
production of small, sharp-edged flakes. Therefore, we formally adopted a classificatory
system treating the flaked cobbles as 'cores' instead of 'tools', following Clark and
Kleindienst (1974). Without exception, the specimens so far recovered fail in the subcategory
of unspecialized 'cores' because there is no evidence for preparation of the flaking surface or
striking platfbrms. The overall diminutive nature of the artifacts is reflected in that, almost
without exception, the 'cores', flakes and fragments are smaller than 100 m m in m a x i m u m
dimension. Furthermore, the stone artifact assemblages are distinguishable fi'om the
Cultural beginnings
21
Figure 10 Cores (top) and whole flakes (bottom) recovered from the surface of the
Oldowan site Bodo A5, Middle Awash.
Acheulian assemblages tbund elsewhere in the Middle Awash inasmuch as they are
completely devoid of bifaces.
Survey elsewhere on the east side of the Middle Awash produced stone artifact occurrences
that can only tentatively be assigned to the Oldowan Industrial Complex. At Matabaietu, in
addition to relocating a site where a surface Oldowan occurrence had been previously
reported (Larson 1977), small numbers of heavily patinated artifacts were found at several
other localities on the surface amongst well preserved bones of elephant and hippo. No
significance is attached to these associations, however, because of the deflated nature of the
deposits and the probability that geological processes were responsible for the surface
accumulation of stone artifacts and bone. Contrary to earlier publications (Larson 1977;
Kalb, Jolly et al. 1982), the designation of Matabaietu as an Oldowan locality remains
problematic until further field studies are undertaken and well-defined, stratified
archaeological occurrences are discovered and excavated.
The small core and flake component typical of the Oldowan is also characteristic of three
archaeological occurrences discovered in Middle Pleistocene sediments at Hargufia, north of
Bodo. At locality HAR-A6, 60 surface artit~tcts derived from tuffaceous silty sand deposits
were comprised of small amorphously flaked cobbles, diminutive 'cores', small flakes and
fragments (Table 2). Their age and stratigraphic position relative to other archaeological
occurrences at Hargufia as well as to other Oldowan occurrences in the Middle Awash
remain to be determined.
22
John W. K. Harris
Implications of the Hadar and Middle Awash archaeological occurrences
Cultural affinities
The Gona River artifact occurrences indicate that by approximately 2.5 million years ago
early hominids had already mastered the art of simple percussion stone flaking. The
discovery of cores and the residue from flaking reduction sequences--whole flakes and
broken flakes--attest to a rudimentary knowledge of the use of conchoidal fracture to
produce simple stone implements. In this preliminary report, the West Gona sample of
flaked cobbles are treated as cores. This classification is based firstly on the lack of abrasion
on the sharp angular 'core' edges. Secondly, more recent studies on artifact assemblages of
similar character suggest that flaked cobbles or 'cores' are likely to represent the by-products
of least-effort solutions to obtain sharp-edged flakes, which then served as 'tools' (Bunn et al.
1980; Toth 1982). On the other hand, if Mary Leakey's typology (1971) based upon
morphological criteria is adopted, then amongst the combined sample of flaked cobbles from
the West Gona and the Kada Gona 2-3-4 sites, choppers, polyhedrons and discoids, which
are characteristic of the 'shaped tool' category, are clearly present. Therefore, the
occurrences t?om the Gona River are attributed to the Oldowan Industrial Complex because
of broad similarities, in technological and morphological features and in the overall
assemblage composition, to well-defined occurrences described particularly from Olduvai
Gorge Bed I and the Koobi Fora Formation, east of Lake Turkana (M. D. Leakey 1971;
Isaac and Harris 1978). In addition, occurrences of this character belonging to a 'core' or
'core tool' and flake craft tradition are compatible with the definition of the dominant lithic
technology of mode 1: chopper tools and flakes (G. Clark 1969). However, the Gona artifacts
are significantly older and predate previously documented Oldowan type occurrences by
approximately 500,000 years.
The earliest stratified archaeological assemblages recovered from Bodo in the Middle
Awash are similarly characterized by small 'cores' and flakes with the addition of various
flake scraper forms and miscellaneously trimmed pieces. This trend towards relatively more
diversified artifact forms is seen in assemblages recovered from the Upper Member of the
Koobi Fora Formation, attributed to the Karari Industry, and in those belonging to the
Developed Oldowan A found in Middle Bed II at Olduvai Gorge, which also date to
approximately 1.5 myr (Harris 1978; M. D. Leakey 1971). In every instance, however, these
assemblages, on the basis of stratigraphy and absolute age determinations, are older than
assemblages that provide evidence for the removal of large flakes (larger than 100-150 mm)
and contain bifaces, and which have been variously attributed to the Developed Oldowan B
and the Acheulian Industrial Complex in East Africa (Fig. 11). Therefore, the Bodo
assemblages, as well as the Karari and Developed Oldowan A assemblages on technological
and morphological grounds belong to a 'core' or 'core tool' and flake tradition and are most
parsimoniously accommodated in the Oldowan Industrial Complex.
Behavioral inferences
The distribution pattern of stone artifacts in relationship to palaeogeographicat features
across ancient landscapes is a potential source of information regarding early hominid
.....
II I I . . . . .
d
L~
0 0 0 0
o
"'1t'"
"1 I I I i t t
mi
.....
4',0
©
..40411
414.-
• -III I I . . - 0 0
• -.41 4l'--
©
A~snpu I
•0 •
0""
x~,;s~pu I
o
©
¢~
000
.00.
- - - 4 - 4 - 4
.....
t e l
0
....
4---4t--4
.......
fill
.....
O0
5
°-41
....
O0
....
z
0
©
•4
.
.
.
•
.
• O...
I
£~l]]d
;
]l(](]lW
]N]:)OISI]]a
8]I, AO]
'1
',
]N~DOI]d
0
0
Z
z
0
S3HNna~I
vwvxnlvw
ssnvo
uJ
i
41
¢,D
24
.John ~ \ K. Harris
land-use and settlement patterns. Preliminary studies at the West Gona site indicate
archaeological traces of hominid activities close to the margin of a stream channel. This is
consistent with the overall tendency for the earliest archaeological sites to be situated close to
stream courses (Isaac 1982). This choice of location was probably determined by several
factors. In addition to the advantages of water, shade and shelter, plant foods, which
presumably constituted the greater part of the diet of early hominids, are found in their
greatest abundance in these better-watered areas of the landscape. Furthermore, in the case
of the Gona River sites, raw materials for stone tool manufacture were readily available in
nearby stream conglomerates.
The geological context of the earliest archaeological occurrences at Bodo in the Middle
Awash indicates that hominid occupation sites were also located in and around the margins
of stream channels. The 'Middle Bodo' beds show two contrasting lithofacies: fossiliferous
and artifact-bearing gravels, sands and silts, and massive beds of clays, generally
non-fossiliferous and lacking in stone artifacts. Preliminary palaeogeographical reconstruction based upon characteristics of these contrasting depositional environments together with
the distributional pattern of archaeological traces over the landscape suggest hominids were
locating their occupation sites close to the margins of local tributary stream channels in the
more elevated hinterland of the sedimentary basin and avoiding the low-lying swampy
floodplain of the palaeo-Awash in the center of the basin (Clark et al. in prep.). This should be
taken only as a working hypothesis. For example, a similar sort of pattern to the distribution
of a set of archaeological 'sites' with an age of 1.5 myr was observed in the Koobi Fora basin
(Harris 1978; Harris and Isaac 1980). The majority of the archaeological 'sites' were situated
away from the lakeshore in the interior of the sedimentary basin; however, as more became
known of the study area, less conspicuous archaeological traces of the presence of hominids in
lake margin environments were found. These included several much lower density artifact
occurrences and a fossilized faunal occurrence completely devoid of any stone artifacts, yet
containing several bones exhibiting cut marks that could only have been made by a stone
implement (Isaac et al. 1976; Bunn 1982). Both Hadar and the Middle Awash provide rare
opportunities for conducting similar sorts of studies leading to a greater understanding of
early hominid land-use.
The presence of artifacts in the geological record may signify changes in the diet or show
certain dietary preferences by some hominids fbr food items requiring stone implements in
their acquisition and/or preparation (Mann, 1972). In view of marked environmental
changes brought about by more arid conditions as documented in the Lake Turkana basin
and the Afar, interspecific and intraspecific competition for already existing food resources or
the search for alternative food resources to maintain stable populations would have been
heightened between 2.5 myr and 2 myr (Bonnefille 1976; Cerling et al. 1977; Gasse et al.
1980). Circumstantial evidence from the co-occurrence of stone artifacts and fragmentary
fauna at the West Gona site suggests hominid activities related to the preparation and
consumption of meat. This remains to be proven, but it is clear that the pristine sharp flakes
and fragments found at the site would have fimctioned adequately as knives for cutting
through hide and slicing through muscle or sinew. It is suggested that some populations of
early hominids, presumably in part as a response to changing environmental conditions,
were extending their food resource base to include meat in their diet. More importantly,
certain adaptive advantages would result from hominids adopting a diet that included a high
Cultural beginnings
25
protein source such as meat, not the least of which would be in terms of fitness potential
compared to other hominid populations with less nutritious diets obtained perhaps from less
predictable sources (Milton 1981).
In some instances, sites characterized by the concentration of stone artifacts and
fragmentary faunal remains have been referred to as 'home bases' (Isaac 1978). Sites of this
nature found in Bed I at Olduvai and in the Koobi Fora Formation, east of Lake Turkana,
illustrate the idea that new adaptive strategies involving a set of concomitant behaviors
including the transport oftbod and materials, tool making, meat eating and food sharing had
become established by the Early Pleistocene (M. D. Leakey 1971; Potts and Shipman 1981;
Isaac 1981; Bunn et al. 1980). In light of the hominid and archaeological discoveries at
Hadar, these sorts of adaptive behaviors may have taken place significantly earlier in time.
Site 333, located in deposits of the Denen Dora Member at Hadar, offers indirect evidence
of a different kind from an earlier time horizon ( ~ 3.0 myr). Here the fragmentary fossilized
remains of at least 13 hominid infants, juveniles and adults were recovered. This suggests
that early hominids congregated in groups ~ohanson 1976}. Thus it is possible that selection
pressures were already operating favoring behaviors such as social role differentiation
associated with cooperative subsistence strategies and reciprocal food sharing in order to
maintain cohesive social groups consisting of adults, children and perhaps aged or
non-productive members. Furthermore, it has been pointed out that such social behavioral
adaptations favored through natural selection may have had a profound influence on the
reorganization and expansion of the brain (Holloway 1973; Wolpoff 1980; Isaac 1981).
Therefore, the Gona River archaeological occurrences become a critical factor in
determining what sort of behavioral adaptations were manifested by at least 2.5 million years
ago. The discovery of early stone artifacts denotes a shift in foraging behaviors which
required the utilization ofsimpte stone implements with sharp as well as blunted edges. The
manufacture of opportunistically flaked objects with sharp edges, in particular, presumably
arose out of new sets of activities requiring simple cutting, scraping or piercing devices,
marking the beginning of an awareness in the relationship between form and function. As
suggested above, their association with fragmentary bone at the West Gona site possibly
indicates a broadening of the food resource base by some populations of hominids to include
the consumption of meat. Also, the low energy fine-grained nature of the sedimentary
deposits containing the artifacts at the site provides evidence for the transportation of stone
by early hominids. Cobblestones, later flaked at the 'site', and/or already fabricated stone
artifacts were transported from a source area and were concentrated on the floodplain near
the margins of a stream as a result of hominid activities. Until large scale excavations are
undertaken at the West Gona site and the co-occurrence of stone artifacts and faunal remains
is described and defined in detail, any further elaboration of behavioral adaptations based
upon the present archaeological evidence would be premature.
Although hominid activities related to the manufacture and use of simple stone artifacts
may reflect a growing advance in mental capacity, whether or not these represent the
behavioral manifestations of a larger-brained hominid remains a critical but an unresolved
issue. Unfortunately, there is only one locality, the Shungura Formation in the Omo River
Valley, yielding hominid specimens from the fossil record sampling the time range (2.5
myr-2.0 myr) bearing on this issue (Howell and Coppens 1976; Howell 1978; Boaz 1979).
Here the earliest specimens attributed to Homo date approximately 2.2 million years to 2.0
26
John W. K. Harris
million years and are contemporary with the earliest remains of another species,
Australopithecus boisei, although some authors have suggested that this robust australopithecine may have emerged at an earlier time (Coppens 1980; Grine 1981). However, the remains
are fragmentary and provide no information on trends towards brain expansion. The issue
may be resolved in the future by a comprehensive survey tbr hominid remains in the Gona
Area, particularly in the large and well-exposed deposits to the west of the river. The survey
has so far been concentrated in the east and on older deposits, which have yielded hominid
specimens attributed to a primitive australopithecine, Australopithecus afarensis (see Fig. 3).
The Middle Awash Oldowan archaeological occurrences promise to provide further
evidence for reconstructing early hominid adaptive patterns of behavior from slightly
younger ranges of time, approximately 1.5 million years ago. O f potentially great
significance is the evidence for fire. This takes the form of localized patches of clay, which
were baked by fire in antiquity (Clark et al. in prep.). Although these traces of fire appear to
be widespread phenomena in the Middle Awash, they were observed and in one case
sampled close to one of the Oldowan archaeological sites in the Bodo locality. One possibility
is that the fire was the result of hominid activities. Only humans have learned to overcome a
fear of fire that is instinctive amongst animals. Thus, in very real terms, the controlled use of
fire by early hominids would have had an important adaptive advantage as a means of
protection against larger animals and, more particularly, carnivores. On the one hand, it
would have facilitated moves into new and unfamiliar habitats and, on the other, occupation
and more efficient exploitation of drier and more open grassland habitats where bush and
tree cover were more restricted.
It is important to realize that, beginning approximately 1.5 million years ago, there are
archaeological traces that indicate not only the occupation by early hominids of more
elevated areas on the high plateau such as Gadeb (Clark and Kurashina 1979), but that the
drier and presumably more open grassy hinterlands of sedimentary basins in the floor of the
Rift were being more intensively occupied, as for example at Karari near Koobi Fora (Harris
1978; Harris and Isaac 1980). This archaeological evidence for the movements of hominid
groups into highland environments and for the intensification of occupation of others
coincides with the earliest reported traces of fire on early hominid occupation 'sites' at
Chesowanja and Gadeb as well as anomalous but so far inconclusive results from the Karari,
near Koobi Fora (Barbetti et al. 1978, 1980; Gowlett et al. 1981; Harris 1982). In view of the
controversial nature of this evidence the Middle Awash research group is currently treating
the controlled use of fire by early hominids as one of several working hypotheses to account
for the baked clay patches, particularly where they occur in close proximity to the
archaeological occurrences.
Conclusion
The earliest occurrences of stone artifhcts attributed to the Oldowan Industrial Complex
have been described from stratified deposits at the Gona River in the Hadar study area with
an age of approximately 2.5 million years. It was suggested that in part as a response to
environmental changes towards drier and more arid conditions some populations of early
hominids broadened their subsistence base. The utilization of stone as a raw material
probably arose out of the necessity to produce sharp- and perhaps blunt-edged implements
Cultural beginnings'
27
following an adaptive shift in foraging behaviors. Preliminary insights into the range of
activities of Pliocene-age hominids have been described. These studies show that the Gona
River deposits will be a major source of information in the future for the elucidation of
adaptive patterns of behavior of early hominids from late Pliocene periods of time that are
otherwise poorly known in East Africa.
Similarly, preliminary descriptions have been given on the context and characteristics of
Oldowan archaeological occurrences found in deposits in the Middle Awash dating to
approximately 1.5 myr. Future studies of these concentrations of fragmentary but diagnostic
faunas and stone artifacts and their differential distribution across the landscape will provide
opportunities to define a range of adaptive behaviors and to document systematically the
land-use patterns of early hominids occupying the basin. In addition, the Middle Awash
provides a unique opportunity for testing the hypothesis that early hominids had learned the
controlled use of fire.
Acknowledgements
My participation at Hadar was the result of an invitation from Donald Johanson and
Maurice Taieb, co-directors of the International Afar Research Expedition. I am grateful for
their assistance in the field as well as to the Ethiopian and foreign members of the project,
particularly Tom Gray, Bill Kimbell and Bob Walter, who helped with the excavation.
Desmond Clark invited me to join the Middle Awash Research Project and the success of the
archaeological survey was due to all participants in the group. Palaeoanthropological
fieldwork at Hadar and the Middle Awash was made possible by grants from the National
Science Foundation, the National Geographic Society and the L. S. B. Leakey Foundation,
which are gratefully acknowledged. I also thank the Provisional Military Government of
Socialist Ethiopia for permission to work at Hadar and the Middle Awash.
The preparation of this manuscript was made possible by funding from the Graduate
School, University of Wisconsin-Milwaukee and the Holt Family Charitable Trust. Karin
Harris and Mary Korenic helped in its preparation, and I thank Michele Patin for skilled
drafting and Barbara Gittings for typing.
References
Abebe, B., Chavaillon, J. and Sutton, J. E. G.
(eds) 1976. Proceedings, VIIIth Panafrican
Congress of Prehistory and Quaternary Studies.
Addis Ababa: Provisional Military
Government of Socialist Ethiopia, Ministry
of Culture, Sports and Youth Affairs.
Aronson, J. L., Schmitt, T. J., Walter, R. C.,
Taieb, M., Tiercelin, J. J., Johanson, D. C.,
Naesser, C. W. and Nairn, A. E. M. 1977.
New geochronologic and paleomagnetic data
for the hominid-bearing Hadar Formation,
Ethiopia. Nature 267:323-27.
Barbetti, M., Clark, J. D., Williams, F. M. and
Williams, M. A.J. 1980. Palaeomagnetism
and the search for very ancient fireplaces in
Africa. L'Anthropologie 18 (2-3):299-304.
Barbetti, M., Wintle, A. and Ftude, K. 1978.
Preliminary archaeomagnetic and
thermoluminescence measurements in the
search for ancient fireplaces in the Koobi
Fora Formation, Northern Kenya. In Harris,
J. W. K. The Karari Industry: its place in East
African prehistory: pp. 556-83. Ph.D. Thesis,
University of California. Ann Arbor:
University microfilms.
Bishop, W. W. and Clark, J. D. (eds) 1967.
Background to evolution in Africa. Chicago:
University of Chicago Press.
28
John t¥. K. Harris
Boaz, N. T. 1979. Hominid evolution in
Eastern Africa during the Pliocene and early
Pleistocene. In Annual Review of Anthropology
(eds B. J. Siegel, A. R. Beals and S. A.
Tyler): pp. 71-85. California: Annual
Reviews, Inc.
Bonnefille, R. 1976. Palynological evidence for
an important change in the vegetation of the
Omo Basin between 2.5 and 2 million years.
In Earliest man and environments in the Lake
Rudolf basin (eds Y. Coppens, F. C. Howell,
G. L. Isaac and R. E. F. Leakey): pp.
421-31. Chicago: University of Chicago
Press.
Bonnefille~ R. and Riollet, G. 1980.
Palynologie, vfgftation et climats de Bed I
et Bed I I / t Olduvai, Tanzanie. In
Proceedings, VIIIth Panafrican Congress of
Prehistory and Quaternary Studies (eds R. E.
Leakey and B. A. Ogot): pp. t23-27.
Nairobi.
Bunn, H. T. 1982. Meat-eating and human
evolution: studies of the diet and subsistencepatterns
of Plio-Pleistocene hominids in East Africa, Ph.D.
Thesis, University of California, Berkeley.
Bunn, H. T., Harris, J. W. K., Isaac, G. LI.,
Kaufulu, Z., Kroll, E., Schick, K., Toth, K.
and Behrensmeyer, A. K. 1980. FxJj 50: an
Early Pleistocene site in northern Kenya.
World Archaeology 12(2):109-36.
Cerling, T. E., Hay, R. L. and O'Neil, J. R.
1977. Isotopic evidence for dramatic climatic
changes in East Africa during the
Pleistocene. Nature 267:137-38.
Chavaillon, J. 1976. Evidence for the technical
practices of Early Pleistocene hominids,
Shungura Formation, Lower Omo Valley,
Ethiopia. In Early man and environments in the
Lake Rudolf basin (eds Y. Coppens, F. C.
Howell, G. LI. Isaac and R. E. F. Leakey):
pp. 565-73. Chicago: University of Chicago
Press.
Chavaillon, J., Chavaillon, N., Hours, F. and
Piperno, M. 1979. From the Oldowan to the
Middle Stone Age at Melka-Kunture
(Ethiopia): understanding cultural changes.
Quaternaria 21:87-114.
Clark, J. D., Cole, G. H., Isaac, G. L1. and
Kleindienst, M. 1966. Precision and
definition in African archaeology; S. AffL
Arch. Bull. 2(83):t 14-2t.
Clark, J. D. and Kleindienst, M. R. 1974. The
Stone Age cultural sequence: terminology,
typology and raw material. In Kalambo Falls
Prehistoric Site, Vol. H (ed. J. D. Clark): pp.
71-106. Cambridge: Cambridge University
Press.
Clarke, J. D. and Kurashina, H. 1979.
Hominid occupation of the east-central
highlands of Ethiopia in the Plio-Pleistocene.
Nature 282:33-39.
Clark, J. D., Asfaw, B., Ilarris, J. W. K.,
Walter, R., White, T. D. and Williams,
M. A. J. in prep. Palaeoanthropological
discoveries in the Middle Awash valley,
Ethiopia.
Clark, G. 1969. World prehistory. A new outline.
London: Cambridge University Press.
Coppens, Y. 1980. The differences between
Australopithecus and Homo: preliminary
conclusions from the Omo Research
Expedition's studies. In Current Argument on
Early Man (ed. L-K. Konigsson): pp. 207-25.
Oxford: Pergamon Press.
Corvinus, G. 1975. Palaeolithic remains at the
Hadar in the Afar region. Nature 256:468-71.
Corvinus, G. 1976. Prehistoric exploration at
Hadar, Ethiopia. Nature 261:57t-72.
Corvinus, G. and Roche, H. 1976. La
prfihistoire darts la r~gion d'Hadar (Bassin
de l'Awash, Afar, Ethiopie): premiers
rfisultats. L'Anthropologie 80(2):315-24.
Corvinus, G. and Roche, H. 1980. Prehistoric
exploration at Hadar in the Afar (Ethiopia)
in 1973, 1974 and 1976. In Proceedings, VIIIth
Panafrican Congress of Prehistory and Quaternary
Studies (eds R. E. F. Leakey and B. A.
Ogot): pp. 186-88. Nairobi.
Curtis, G. H. and Hay, R. L. 1972. Further
geologic studies and potassium-argon dating
at Olduvai Gorge and Ngorongoro Crater.
In Calibration of hominoid evolution (eds W. W.
Bishop and J. A. Miller): pp. 289-301.
Edinburgh.
Drake, R. E., Curtis, G. H., Ceding, T. E.,
Cerling, B. W. and Hampel, J. 1980. KBS
Tuff dating and geochronology of tuffaceous
sediments in the Koobi Fora and Shungura
Formations, East Africa. Nature 283:368-72.
Eck, G. G. 1976. Cercopithecoidea from Omo
Group deposits. In Earliest man and
environments in the Lake Rudolf basin (eds Y.
Coppens, F. C. Howell, G. LI. Isaac and
R. E. F. Leakey): pp. 332-44. Chicago:
University of Chicago Press.
Gasse, F., Rognon, P. and Street, F. A. 1980.
Cultural beginnings
29
Harris, J. W. K. and Johanson, D. C. 1982.
Quaternary history of the Afar and
Archaeological discoveries in the Afar region,
Ethiopian Rift lakes. In The Sahara and the
Ethiopia: the Gona archaeological site. In
Nile (eds M. A. J. Williams and H. Faure):
XIth Congress of the International Union for
pp. 261-400. Rotterdam: A. A. Balkema.
Quaternary Research (INQUA), vol. 11:98.
Gentry, A. W. 1976. Bovidae from the East
~OSCOw.
Rudolf succession. In Earliest man and
Hay, R. L. 1976, Geology of the Olduvai Gorge.
environments in the Lake Rudolf basin (eds Y.
Berkeley: University of California Press.
Coppens, F. C. Howell, G. L1. Isaac and
Heinzelin, J. de, Haesaerts, P. and Howell,
R. E. F. Leakey): pp. 275-92. Chicago:
F. C. 1976. Plio-Pleistocene Formations of
University of Chicago Press.
the Lower Omo basin, with particular
Gowlett, J. A. J., Harris, J. W. K., Walton, D.
reference to the Shungura Formation. In
and Wood, B. A. 1981. Early archaeological
sites, hominid remains and traces of fire
Earliest man and environments in the Lake Rudolf
basin (eds Y. Coppens, F. C. Howell, G. L1.
from Chesowanja, Kenya. Nature 294:125-29.
isaac and R. E. F. Leakey): pp. 24-49.
Gray, B. T. 1980. Environmental reconstruction of
Chicago: University of Chicago Press.
the Hadar Formation, Afar, Ethiopia. Ph.D.
Holloway, R. L. 1973. Endocranial volumes of
Thesis, Case Western Reserve University.
early African hominids, and the role of the
Gray, B. T., Beden, M., Guerin, C., Taieb,
brain in human mosaic evolution. Journal of
M., Tiercelin, J.-J. and Page, N. 1980.
Environmental indications provided by the
Human Evolution 2:449-59.
Hadar Formation (Afar, Ethiopia): fauna
Howell, F. C. 1978. Hominidae. In Evolution of
and correlation with geological evidence. In
African mammals (eds V. J. Maglio and
H. B. S. Cooke): pp. 154-248. Cambridge:
Proceedings, VIIlth Panafrican Congress of
Harvard University Press.
Prehistory and Quaternary Studies (eds R. E. F.
Howell, F. C. and Coppens, Y. 1976. An
Leakey and B. A. Ogot): pp. 115-17.
overview of Hominidae from the Omo
Nairobi.
succession, Ethiopia. In Earliest man and
Grine, F. E. 1981. Trophic ditt~rences between
'gracile' and 'robust' Australopithecines: a
environments in the Lake Rudolf basin (eds Y.
scanning electron microscope analysis of
Coppens, F. C. Howell, G. L1. Isaac and
R. E. F. Leakey): pp. 522-32. Chicago:
occlusal events. South African Journal of Science
Chicago University Press.
77:203-30.
Isaac, G. LI. 1976. Plio-Pleistocene artifact
Harris, J. W. K. 1978. The Karari Industry: its
assemblages from East Rudolf, Kenya. In
place in East Africa prehistory. Ph.D. Thesis,
University of California. Ann Arbor:
Earliest man and environments in the Lake Rudolf
basin (eds Y. Coppens, F. C. Howell, G. L1.
University Microfilms.
Isaac and R. E. F. Leakey): pp. 552-64.
Harris, J. W. K. 1980. Early Man. In The
Chicago: University of Chicago Press.
Cambridge encyclopedia of archaeology (ed. A.
Isaac, G. Ll. 1978. The tbod sharing behavior
Sherratt): pp. 62-70. London: Cambridge
of protohuman hominids. Scientific American
University Press.
238:90-108.
Harris, J. W. K. 1982. Quest for fire: the
Isaac, G. L1. 1981. Emergence of human
Chesowanja evidence. Anthro Quest (L. S. B.
behavior patterns. Archaeological tests of
Leakey Foundation Newsl.) 24:9-10.
alternative models of early hominid
Harris, J. W. K. in press. Oldowan
behavior: excavation and experiments. Phil.
archaeological findings in the Afar Rift. In
Trans. R. Soc. Lond. B 292:177-78.
Proceedings of the 1st International Congress of
Isaac, G. L1. 1982. The earliest archaeological
tIuman Palaeontology (eds H. de Lumley and
traces. In The Cambridge History of Africa, vol.
M.-A. de Lumley). Nice.
1. (ed. J. D. Clark): pp. 157-247. London:
Harris, J. W. K. and Isaac, G. LI. 1980. Early
Cambridge University Press.
Pleistocene site locations at Koobi Fora,
Isaac, G. LL and Harris, J. W. K. 1978.
Kenya. In Proceedings, VIIIth Panafrican
Archaeology. In Koobi Fora Research Project,
Congress of Prehistory and Quaternary Studies (eds
vol. 1. (eds M. G. Leakey and R. E. F.
R. E. F. Leakey and B. A. Ogot): pp. 205-7.
Leakey): pp. 64-85. Oxford: Clarendon Press.
Nairobi.
30
John W. K. Harris
Isaac, G. L1., Harris, J. W. K. and Crader, D.
1976. Archaeological evidence from the
Koobi Fora Formation. In Earliest man and
environments in the Lake Rudolf basin (eds Y.
Coppens, F. C. Howell, G. L1. Isaac and
R. E. F. Leakey): pp. 533-51. Chicago:
University of Chicago Press.
Jaeger, j. j. and Wesselman, H. B. 1976. Fossil
remains of micromammals from the Omo
Group deposits. In Earliest man and
environments in the Lake Rudolf basin (eds Y.
Coppens, F. C. Howell, G. L1. Isaac and
R. E. F. Leakey): pp. 351-60. Chicago:
University of Chicago Press.
Johanson, D. C. 1976. Ethiopia yields first
'family' of early man. Natl. Geograph.
150(6):790--8t 1.
Johanson, D. C. and Coppens, Y. 1976. A
preliminary anatomical diagnosis of' the first
Plio-Pleistocene hominid discoveries in the
central Afar, Ethiopia. Am. J. Phys. Anthropol.
45:217-34.
Johanson, D. C. and Edey, M. 1981. Lucy, the
beginnings of humankind. New York: Simon and
Schuster.
Johanson, D. C. and Taieb, M. 1976.
Plio-Pleistocene hominid discoveries in
Hadar, Ethiopia. Nature 260:293-97.
Johanson, D. C. and Taieb, M. 1978.
Plio-Pleistocene hominid discoveries in
Hadar, Central Afar, Ethiopia. In Early
hominids of Africa (ed. C. J. Jolly): pp. 2944.
New York: St Martins.
Johanson, D. C., Taieb, M. and Coppens, Y.
1982. Pliocene hominids from the Hadar
Formation, Ethiopia (1973.1977):
stratigraphic, chronological and
paleoenvironmental contexts, with notes on
hominid morphology and systematics. Am. J.
Phys. Anthropol. 57:373-402.
Johanson, D. C. and White, T. D. 1979. A
systematic assessment of early African
hominids. Science 202:321-30.
Johanson, D. C., White T. and Coppens, Y.
1978. A new species of the genus
AustraIopithecus (Primates: Hominidae) from
the Pliocene of eastern Africa. Kirtlandia
28:1-14.
Kalb, J. E. 1978. Mio-Pleistocene deposits in
the Afar Depression, Ethiopia. Sinet Ethiop. J.
Sc/. I(2):87-98.
Kalb, J. E., Jolly, C. J., Mebrate, A., Tebedge,
S., Smart, C., Oswald, E. B., Cramer, D.,
Whitehead, P., Wood, C. B., Conroy, G. C.,
Adefris, T., Sperling, L. and Kana, B. 1982.
Fossil mammals and artifacts from the
Middle Awash valley, Ethiopia. Nature
298:25-29.
Kalb, J. E., Oswald, E. B., Tebedge, S.,
Mebrate, A., Tola, E. and Peak, D. 1982.
Geology and stratigraphy of Neogene
deposits, Middle Awash valley, Ethiopia.
Nature 298:17-25.
Larson, P. A. 1977. Matabaietu: an Oldowan
site from the Afar, Ethiopia. Nyame Akuma
11:6-10.
Leakey, M. D. 1971. Olduvai Gorge, Vol. III.
London: Cambridge University Press.
Leakey, M. D., Hay, R. L., Curtis, G. H.,
Drake, R. E., Jackes, M. K., and White,
T. D. 1976. Fossil hominids from the Laetoli
Beds. Nature 262:460-66.
Leakey, M. G. 1980. Evidence of
palaeoenvironmental changes in the Turkana
Basin from some extinct Cercopithecoidea.
In Proceedings, VIIIth Panafrican Congress on
Prehistory and Quaternary Studies. (eds R. E. F.
Leakey and B. A. Ogot): pp. 128-30.
Nairobi.
Leakey, R. E. F. t976. New hominid fossils
from the Koobi Fora Formation in northern
Kenya. Nature 261:574-76.
Mann, A. 1972. Hominid and cultural origins.
Man 7(3):379-86.
McDougall, I., Maier, R., Sutherland-Hawkes,
P. and Gleadow, A. J. W. 1980. K-Ar
estimate for the KBS Tuff, East Turkana,
Kenya. Nature 284:230-34.
Merrick, H. V. 1976. Recent archaeological
research in the Plio-Pleistocene deposits of
the Lower Omo, southwestern Ethiopia. In
Human origins. (eds G. L1. Isaac and E.
McCown): pp. 461-81. Menlo Park: W. A.
Benjamin.
Merrick, H. V. and Merrick, J. P. S. 1976.
Archaeological occurrences of earlier
Pleistocene age from the Shungura
Formation. In Earliest man and environment.s in
the Lake Turkana basin. (eds Y. Coppens,
F. C. Howell, G. L1. Isaac and R. E. F.
Leakey): pp. 574-84. Chicago: University of
Chicago Press.
Milton, K. 1981. Distribution of patterns of
tropical food plants as an evolutionary
stimulus to primate mental development.
American Anthropologist 83:534-48.
Cultural beginnings
Potts, R. and Shipman, P. 1981. Cutmarks
made by stone tools on bones from Olduvai
Gorge, Tanzania. Nature 291:577-80.
Roche, H. and Tiercelin, J . J . 1977.
Dficouverte d'une industrie lithique ancienne
in situ dans ta formation d'Hadar, Afar
central, Ethiopie. C.R. Acad. Sci. Paris D
284:1871-74.
Roche, H. and Tiercelin, J. J. 1980. Industries
lithiques de la formation plio-pl~istoc~ne
d'Hadar: campagne 1976. In Proceedings,
VIIIth Panafrican Congress of Prehistory and
Quaternary Studies (eds R. E. F. Leakey and
B. A. Ogot): pp. 194-99. Nairobi.
Schmitt, T.J., Walter, R. C., Taieb, M.,
Tiercelin, J. j. and Page, N. 1980.
Magnetostratigraphy of the Hadar
Formation. tn Proceedings, VIIIth Panafrican
Congress of Prehistory and Quaternary Studies (eds
R. E. F. Leakey and B. A. Ogot): pp. 53-55.
Nairobi.
Taieb, M. 1974. Evolution quaternaire du bassin de
I'Awash. Ph.D. Thesis, L'Universit~ de Paris
VI.
Taieb, M., Johanson, D. C., Coppens, Y. and
Aronson, J. C. 1976. Geological and
paleontological background of Hadar
hominid site, Afar, Ethiopia. Nature
260:288-93.
Taieb, M., Johanson, D. C., Coppens, Y. and
Tiercelin, J. J. 1978. Expedition
internationale de l'Afar, Ethiopie (4e et 5e
31
campagnes 1975-1977): chronostratigraphie
des gisements ~t hominides plioc~ne de
l'Hadar et correlations avec les sites
pr~historiques du Kada Gona. C.R. Acad. Sei.
Paris D 287:459-61.
Taieb, M. and Tiercelin, J . J . 1979.
Sedimentation pliocbne et
pal~oenvironnements de rift: exemple de ta
formation 5- horninides d'Hadar (Afar,
Ethiopie). Bull. Soc. Ggol. France 21:243-53.
Toth, N. 1982. The stone technologies of early
hominids at Koobi Fora, Kenya: an experimental
approach. Ph.D. Thesis, Universit'/of
California. Ann Arbor: University
Microfilms.
Walker, A. C. and Leakey, R. E. F. 1978. The
hominids of East Turkana. Scientific American
239(2) :54-66.
Walker, A., Zimmerman, M. R. and Leakey,
R. E. F. 1982. A possible case of
hypervitaminosis A in Homo erectus. Nature
296:248-50.
Walter, R. C. 1980. The volcanic history of the
Hadar early man site and the surrounding Afar
region of Ethiopia. Ph.D. Thesis, Case Western
Reserve University.
Walter, R. C. and Aronson, J. L. 1982.
Revisions of K/Ar ages for the Hadar
hominid site, Ethiopia. Nature 296:
122-27.
Wolpoff, M. H. 1980. Paleoanthropology. New
York: A. A. Knopf, Inc.