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Ichnos: An International Journal for Plant and Animal
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Pliocene Animal Trackways at Laetoli: Research and
Conservation Potential
Charles M. Musiba
a
, Audax Mabula
b
, Marie Selvaggio
c
& Cassian C. Magori
d
a
Department of Anthropology , University of Colorado , Denver, Colorado, USA
b
Department of History , University of Dar Es Salaam , Dar Es Salaam, Tanzania
c
Department of Anthropology , Southern Connecticut State University , New Haven,
Connecticut, USA
d
Department of Anatomy and Histology , Bugando University College of Health Sciences ,
Mwanza, Tanzania
Published online: 02 Dec 2008.
To cite this article: Charles M. Musiba , Audax Mabula , Marie Selvaggio & Cassian C. Magori (2008) Pliocene Animal Trackways
at Laetoli: Research and Conservation Potential, Ichnos: An International Journal for Plant and Animal Traces, 15:3-4,
166-178, DOI: 10.1080/10420940802470383
To link to this article: http://dx.doi.org/10.1080/10420940802470383
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Ichnos, 15:166–178, 2008
Copyright
c
Taylor & Francis Group, LLC
ISSN: 1042-0940 print / 1563-5236 online
DOI: 10.1080/10420940802470383
Pliocene Animal Trackways at Laetoli: Research and
Conservation Potential
Charles M. Musiba,
1
Audax Mabula,
2
Marie Selvaggio,
3
and Cassian C. Magori
4
1
Department of Anthropology, University of Colorado, Denver, Colorado, USA
2
Department of History, University of Dar Es Salaam, Dar Es Salaam, Tanzania
3
Department of Anthropology, Southern Connecticut State University, New Haven, Connecticut, USA
4
Department of Anatomy and Histology, Bugando University College of Health Sciences,
Mwanza, Tanzania
Laetoli, a paleoanthropological site in Northern Tanzania, is
perhaps best known for its famous fossil hominid footprints that
were discovered by Mary Leakey and her co-workers in 1978.
The site not only preserves the hominid footprints but also track-
ways, which provide a snapshot of Pliocene faunal communities
from East Africa and their inferred environments. Unlike the
hominid footprints at site G, which have received tremendous
attention, the animal trackways, especially at Localities 7, 8 and
10 have been neglected and are fast disappearing. In this paper,
we discuss animal tracks at a newly discovered exposure and
provide preliminary data on the tracks at this exposure and other
sites. We also discuss the importance of the animal trackways as
ecological indicators, which we have investigated as part of ongoing
research and conservation efforts initiated by the Tanzania Field
School in Paleoanthropology and the Associated Colleges of the
Midwest (ACM) Tanzania Semester Abroad programs.
Keywords Laetoli, animal trackways, paleoecology, animal track-
way conservation
INTRODUCTION
The uniqueness of Laetoli as an ecologically significant
Pliocene upland site in eastern Africa makes it particularly
well suited for multifaceted paleoenvironmental studies. For
example, the Laetoli paleobiota (Table 1) and the ichnofossil
record (Table 2) contains a wide diversity of species whose
ancestors today occupy a variety of habitats ranging from open
grassland to brush and woodland (Kent, 1941; Leakey et al.,
1976; Leakey and Hay, 1979; Leakey, 1981; Hay, 1978, 1980,
1987; Ndessokia, 1990; Manega, 1993; Kyauka, 1994; Musiba,
1999). As a Pliocene site, Laetoli differs significantly from other
Address correspondence to Charles M. Musiba, Department of
Anthropology, University of Colorado at Denver and Health Sciences
Center, Campus Box 103, P.O. Box 173364, Denver, CO 80217-3364.
E-mail: Charles.Musiba@ucdenver.edu
African paleoanthropological sites such as Hadar or Koobi Fora,
which primarily formed in fluviatile-lacustrine or floodplain
deposits (Butzer, 1974; Coppens et al., 1976; Coffing et al.,
1994; Feibel et al., 1989; Johanson and Edey, 1981; Vrba, 1975,
1985a & b, 1995, 2000; WoldeGabriel et al., 1994; Wood and
Collard, 1999). Laetoli formed entirely on Aeolian volcanic
tuffs with no major lakes or rivers. The Laetoli vertebrate
fossil fauna is also of great interest because its taxonomic
composition differs from that of other East African fauna of
comparable age (Gentry, 1981; Harris, 1985; Verdcourt, 1987).
Most remarkable are the Footprint Tuffs at Laetoli in which
tracks and trails of a great variety of animals, many of which are
long extinct and are well-preserved (Day and Wickens, 1980;
Leakey, 1981, 1987). In this paper we present some preliminary
inferences concerning Laetoli’s past ecological setting through
analyses of Laetoli’s animal trackways—their identification,
distribution, composition and significance as paleoecological
indicators—with an emphasis on the site conservation efforts
currently undertaken by our team.
The Pliocene site of Laetoli is located about 36 kilometers
south of Olduvai Gorge in northern Tanzania (Fig. 1). This
site, which covers an area about 100 km
2
,
may be viewed as
contiguous with Olduvai Side Gorge, where fossiliferous strata
of volcanic origin spanning from 4.32±0.06 to 0.21 ± 0.02 Ma
occur (Hay, 1978; Drake and Curtis, 1987; Manega, 1993).
The geology, geochronology, and stratigraphy of Laetoli with
its fossil bearing deposits and footprint horizons have been
described in detail by Hay (1978), Drake and Curtis (1978), and
Manega (1993). The footprint horizons, which are referred to as
the Footprint Tuffs, consist of ash particles mainly cemented by
calcite and less commonly by phillipsite (Hay, 1987).
Previous paleoanthropological research at Laetoli by Leakey
and her co-workers produced more than 20 fragments of
cranial and post-cranial remains of fossil hominids ranging from
Australopithecus afarensis to anatomically modern humans
(White 1977, 1980; Day and Magori, 1980). Other significant
166
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PLIOCENE ANIMAL TRACKWAYS AT LAETOLI 167
TABLE 1
Partial list of common mammals
1
(nonhuman) in the fossil
record from Laetoli (Laetolil and Upper Ndolanya beds (after
Leakey, 1987; Harris, 1987; Hooijer, 1987; Gentry, 1987;
Davies, 1987).
Taxa
No. of
species/genera NISP (%)
Cercopithecidae 5 91 (0.8)
Elephantidae 2 246 (2.1)
Equidae 4 371 (3.2)
Leporidae 1 992 (25.6)
Pedetidae 2 94 (1.6)
Rodentia 22 402 (3.4)
Carnivora (all taxa) 24 266 (2.3)
Rhinocerotidae 2 671 (5.6)
Giraffidae 4 897 (7.6)
Suidae 3 334 (2.7)
Bovidae 22 5248 (44.9)
Total 91 11706 (96.8)
NISP = Number of identified specimen per taxon.
1
The taxa listed are represented by more than 100 identifiable
specimens.
discoveries at Laetoli include a trail of footprints generally
attributed to Australopithecus afarensis made by two or three
individuals and dated to 3.56 million years ago. These are
well preserved in volcanic ash within the Upper and Lower
Laetolil Beds (Leakey, 1981, 1987). Laetolil Beds is the official
term used to define the oldest deposits: the orthography is
different from the site name: Laetoli (Hay, 1987; Leakey
1987). The Footprints Tuffs, which are fine-grained volcanic ash
layers, document the world’s only undisputed footprint evidence
for the origin of habitual bipedal locomotion in the human
lineage during the Pliocene (Leakey, 1987; Tuttle, 1987, 1992).
Additionally, animal and avian tracks including raindrop prints
are also well preserved within the Footprint Tuffs. Laetoli’s
stratigraphic sequence, particularly the Ndolanya Beds also
contain numerous stone artifacts and an early manifestation of
the Middle Stone Age (MSA) or “Sangoan” traditions (Mabulla,
in preparation; Ndessokia, 1990).
THE FOOTPRINT TUFFS
Tracks and prints of animals and birds, which have been
discovered and identified at Laetoli, are known from 18 exposed
footprint horizons referred to as the Footprint Tuffs within
Localities 2, 7, 7 East, 9, 10 East, 11, 13, and 14 (Fig. 1). The
sites at these localities are listed from A–P (see Leakey, 1987 for
details). At Laetoli, the animal, avian, and insect tracks, raindrop
imprints and the fossil faunal remains are unique in terms
of their exceptional preservation. The stratigraphic sequences
and geochronology of the Laetoli site were described in detail
by Hay (1978, 1980, 1987), Drake and Curtis (1987), and
Manega (1993). The strata comprise a variety of volcanoclastic
units of varying thickness and composition. According to
Hay (1987), the source of the Laetolil Beds was a volcanic
eruption at Sadiman, which is located 15 km east of Laetoli.
The Footprint Tuffs are of eolian tuff origin (with grain size
ranging from 0.05—0.40 mm) interbedded with widespread
raindrop horizons. The tuff layers were precisely dated Drake
and Curtis (1987) and Manega (1993) using K/Ar and Ar/Ar
dating methods. Hay (1987) also produced paleomagnetic dates
complimenting the K/Ar and Ar/Ar dates, and believes that the
Footprint Tuff was deposited over a period of few weeks at the
end of the dry season and into the beginning of the rainy season.
The animal and avian trackways at Laetoli occur within the
Laetolil Beds, between the Footprint Tuffs 3 and 14 in the lower
unit and between tuffs 1 and 4 in the upper unit (Hay, 1987).
Almost immediately after the rainfall, animals, birds, insects and
hominids walked on the wet ash surface. The footprints were
buried by subsequent ash falls, allowing them to be preserved.
Later, water and wind erosion re-exposed the prints.
TABLE 2
List of identifiable insects, birds and mammal
taxa from the footprints and trackways within the
Footprint Tuffs (after Leakey, 1987)
Taxa
Insects (including termitaries)
Struthianidae
Aves indet.
Phasianidae (guinea-fowl)
Lagomorpha
Cercopithecidae
Carnivora indet.
Hyaenidae
Proboscidea
Hipparion
Chalicotheridae (including Ancylotheriopus
tanzaniae ichnosp. nov.)
1
Rhinocerotidae
Suidae
Giraffidae
Simatherium kohllarseni
Hominidae gen. et sp. indet.
2
Bovidae (including Madoqua), and various indet.
1
Synonymous with Ancylotherium hennigi per
Leakey and Harris (1987).
2
The Laetoli hominid footprints have been attributed
to Australopithecus afarensis by many researchers.
However, the footprint structure and the inferred pedal
morphology of the Laetoli bipeds do not fit the morphol-
ogy of Australopithecus afarensis (Tuttle, 1991).
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168 C. M. MUSIBA ET AL.
FIG. 1. Map of Laetoli showing the paleoanthropological localities (numbers) and animal trackways (letters).
CURRENT STATUS OF THE ANIMAL TRACKWAYS
AT LAETOLI
Unlike the hominid footprints, which have received much
attention and media publicity geared towards their conservation
in 1996–98 (Agnew and Demas, 1998; Demas et al., 1996;
Feibel et al., 1995), the animal trackways at Laetoli have been
neglected. Since Leakey and her co-worker’s detailed study of
the animal and avian tracks in 1987, no further systematic
studies of the exposed animal tracks have been conducted.
Recent observations by our teams during field school sessions
at Laetoli indicate an alarmingly rapid disappearance of the
prints that were initially documented by Leakey (1987) through
both erosion and animal trampling (Fig. 2). Unfortunately, there
seems to be no future plans for preservation and documentation
of these important ichnofossil trails. The present study was
conducted by our teams during four consecutive one month field
seasons (2002–2005), as part of ongoing summer field school
and semester abroad programs for anthropology undergraduate
students from the United States and Tanzania. The major
objectives of our study were: a) to document the existing
animal trackways as well as new exposures, b) to re-evaluate
the exposed animal and avian trackways and the footprint tuffs
in terms of their conservation needs, and c) to use the animal
trackways to construct species abundance estimates and use
that data in paleoecological interpretations of Pliocene Laetoli
(particularly within the Upper Laetolil Beds).
MATERIAL AND METHODS
Recording the Animal Trackways
A total of six footprint sites were systematically surveyed,
three in each field season. Five of the surveyed sites were
previously described by Leakey et al. in 1987. These include;
site C at Locality 7, site D at Locality 11, site J at Locality
10 East, and sites L1 and L2 at Locality 13. The sixth site is
new and was brought to our attention by Mr. Simon Mataro,
a Maasai elder and guard of the hominid footprints at site G
(Locality 8). This newly discovered site was named site Q
within Locality 8, following Leakey’s (1987) site naming system
(Fig. 1).
Initial fieldwork at the animal trackway sites included setting
up transects with grid systems of 1 m × 1 m squares on a
10 m long segment of exposed footprint tuffs (Fig. 4). Then
the sites were cleared of any overburden to expose the animal
trackways for the detailed studies. The prints were cleaned using
soft brushes and brooms to reveal detailed features. Dental
and softwood picks were used to remove fine-grained debris
from the footprints, particularly prints that were selected to
be photographed. Extreme care was taken to ensure that the
footprints were not damaged in the process. Exposed prints
were mapped and identified in consultation with Mr. Mataro,
following the field guide to tracks of Stuart and Stuart (1994)
and Leakey’s 1987 initial report on identified prints.
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PLIOCENE ANIMAL TRACKWAYS AT LAETOLI 169
FIG. 2. (A) Maasai herders driving their livestock near Site O at Locality 14. (B) Photograph showing the extent of erosion on animal footprints at Site C
Locality 7. (See Color Plate XV)
At each site, werecorded the number of identifiable prints,
orientation, length and width of each footprint using digital
calipers and tape measures. Well-preserved prints were mapped,
and photographed and molds were made for archival purposes.
These molds are reposited in the Department of Anthropology
at the University of Colorado at Denver and Health Sciences
Center in Denver and in the Department of Antiquities in Dar
es Salaam, Tanzania. Digital photographs were made and will
be used to digitally monitor the extent of weathering process on
individual prints. At each site, datum points were established
and used for measurements to determine orientation at each
location relative to the datum point (Fig. 3). Hand-held Brunton
compasses were used to measure the angles while tape measures
were used to determine distances between prints.
Every print in our study was given a label. The first part
of the label identifies the locality and the second part is a
number that identifies the order in which the print was found.
For example, the third print identified at Locality 8 was labeled
L8P3 (L8 for Locality 8, and P3 for Print # 3). Due to the
fact that many animal trackways at various sites at Laetoli are
disappearing, at site Q we decided to excavate and record as
many prints as possible. We excavated a portion of the footprint
tuff at this site, in an area that was covered with packed-down
dirt and sand). First we removed the matrix using trowels and
brushes and cleared away the overburden covering the prints.
This exercise was done for two main reasons: first to determine
the condition of the prints and second to identify individual
trackways.
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170 C. M. MUSIBA ET AL.
FIG. 3. Photographs (A & B) showing the established grid system during the documentation and mapping of the animal prints at Site D at Locality 11. (See
Color Plate XVI)
Reconstructing the Laetoli Paleoecology
from the Track Record
The partialreconstruction of the Pliocene Laetoli landscape
using ichnofossil data focused mainly on a comparative
approach that used habitat equivalence and behavioral ecology
of extant animals of the Serengeti Plains. Assuming that Laetoli
animals utilized the landscape in a way similar to their extant
counterparts, our goal was to reconstruct the paleoguilds and
establish possible habitat preferences of the print makers.
Using Kingdon’s (1997) Guide to Mammals of East Africa,
we constructed Laetoli’s Pliocene paleoguilds and established
habitat preferences for each of the animals represented in the
trackways. The data we collected do not necessarily provide
a complete picture of Laetoli’s paleolandscape; however, they
provide us with snapshots of the landscapes that the print-
makers experienced 3.8 million years ago. Therefore, our
paleoenvironmental analysis is currently restricted to qualitative
interpretation of Laetoli’s ancient ecology.
RESULTS
Our preliminary results on the reconstruction of Laetoli mam-
malian and avian paleoguilds is based on qualitative data and
thus restricted in its interpretation to general ecological trends.
The results presented below also provide brief descriptions of
the individual sites that we studied.
Sites Q at Locality 8
Site Q which was discovered in 2003, consists of a small
exposure of only a few square meters. Preservation conditions
of exposed prints on this site are relatively poor and most of
the prints are extremely eroded. We were able to tentatively
identify 28 individual prints that were exposed. The prints are
of ancient species of giraffe, roan antelope, gazelle, guinea fowl,
rhino and buffalo (Table 3A). Conspicuously absent at this site
are Madoqua and lagomorph prints, which are plentiful at other
sites we studied.
Physiographically site Q is located in a channelized gully
undercut by a seasonal stream that erodes and exposes the
footprint tuffs. The majorities of the guinea fowl prints at this
site are extremely eroded and may not survive the torrential
rains of the next few years. Unfortunately, if no action is taken
to preserve these prints it is clear that they will soon disappear.
Furthermore, roots of thorny acacias trees have penetrated and
shattered some of the trackways, while daily herding of goats
TABLE 3
List of identified animal prints/per taxon at Sites Q and R.
Identifiable species
No. of identifiable
prints
% of total
identified prints
A. Site Q
Giraffe 5 17.86
Roan Antelope 4 14.29
Gazelle 3 10.71
Guinea Fowl 13 46.43
Rhinoceros 2 7.14
Buffalo 1 3.57
Total 28 100
B. Site R
Elephant 8 0.44
Madoqua 858 47.69
Lagomorpha 859 47.74
Buffalo 4 0.22
Giraffe 11 0.61
Carnivore indet. 9 0.56
Lion 2 0.11
Baboon 3 0.17
Rhinoceros 7 0.39
Eland 4 0.22
Gazelle 12 0.67
Hartebeest 8 0.44
Roan Antelope 7 0.39
Beetle 1 0.06
Guinea Fowl 5 0.28
Aves indet. 1 0.06
Total 1,799 100
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PLIOCENE ANIMAL TRACKWAYS AT LAETOLI 171
FIG. 4. Photograph showing a 3 × 3 meters excavated trench of on the Footprint Tuffs at Site C, Locality 7. (See Color Plate XVII)
and cattle through thesite exert tremendous damage to the
exposed prints (Fig. 2 and 4). At one end of the exposure, the
tuffs have completely been obliterated and the prints washed or
weathered away. Some of the tuffs at this site however, are still
covered by tightly packed and well sorted matrix.
Site R at Locality 7
Site R at Locality 7 consists of a large exposure of the
footprint tuffs that lie within a seasonal streambed. Large
portions of the exposed tuffs have been eroded, leaving behind
few recognizable prints. Some areas of the exposed tuffs still
harbor many identifiable prints. At this site we were able to
identify 1,799 prints, where a large portion of the prints were
assigned to lagomorphs and Madoqua. Other identifiable prints
represented ancient elephants, buffalos, giraffes, lions, baboons,
rhinoceros, elands, gazelles, hartebeests, roan antelopes, guinea
fowls and beetles. A number of indeterminate carnivore and bird
prints were also found at the site (Table 3B).
Current preservation conditions of the prints at this site are
similar to that of site Q; cattle and goats have frequently been
herded across the exposed tuffs thus severely damaging the
prints.
Sites D at Locality 11
Site D is the largest animal trackway site at Laetoli with
exposed footprint tuffs containing many trails representing
elephants, hyenas and guinea fowl. This site is one of the few
sites where Leakey (1987) extensively documented the animal
trackways. Since then more tuffs have been exposed, and we
were able to identify two of the three hyena trails as well as an
elephant trail that was initially described by Leakey in 1987.
At this site we identified a large number of prints comprising
a wide variety of animals. Again, Lagomorphs and Madoqua
prints dominated the footprint assemblage at Locality D (Table
4A). Additionally, we were able to identify five prints made by
Simatherium kohllarseni, a large extinct bovid.
Large portions of exposed footprint tuffs at the site are
crumbling away due to water erosion and livestock trampling
(Fig. 5). We observed a series of fractures of an evaporitic
nature that run through the footprint tuffs. It was not unusual
to see donkeys, cows or goats milling around on top of the
exposed prints. During the rainy season water puddles form in
large animal prints providing drinking water to goats and other
animals. The Maasai who live nearby also collect rainwater from
the puddles, scraping the prints with plastic buckets and other
utensils.
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172 C. M. MUSIBA ET AL.
TABLE 4
List of identified animal prints/per taxon at Sites D and J.
Identifiable species
No. of
identifiable
prints
% of total
identified prints
A. Site D
Elephants 11 0.80
Madoqua 545 43.18
Lagomorpha 544 43.10
Buffalo 7 0.60
Carnivore indet. 5 0.40
Baboons 7 0.60
Gazelle 2 0.10
Hartebeest 3 0.20
Hyena 52 4.10
Guinea fowls 70 5.50
Aves indet. 2 0.10
Simatherium
kohllarseni
50.40
Indeterminate
trackways
90.70
Totals 1262 100
B. Site J
Elephant 16 12.31
Madoqua 66 50.77
Buffalo 4 3.07
Hyena 5 3.85
Guinea Fowl 37 28.46
Zebra 2 1.54
Total 130 100
Site J at Locality 10 East
Site J lies within a seasonal streambed at Locality 10 East. As
a result, large portions of the exposed tuffs have eroded away,
leaving few recognizable prints. Other areas of the exposures
do contain many identifiable prints, however; we were able
to identify 130 prints, which were dominated by lagomorphs
and Madoqua (Table 4B). The site contains prints of several
large bovids, giraffids and hyenas. Interestingly enough, the
directionality of the giraffe prints are oriented toward the south
while those of zebra, buffalo and hyenas are oriented toward the
northwest direction. Rhino prints are remarkably absent at this
site when compared with site R at Locality 7 (Leakey, 1987).
Sites L1 and L2 at Locality 13
The exposed footprint tuffs at locality 13 measure approx-
imately 68 m
2
on a U-shaped outcrop with an open end to
the south (Leakey, 1987). The area around this site is flat
covered with grasses and isolated thickets. Therefore, the site
is vulnerable to Maasai cattle trampling and erosion by water.
Consequently, large parts of the footprints at this site have been
damaged. Two areas with apparent prints were named as Site L1
and L2, respectively. Site L2 occurs about 50 meters west of L1.
At both sites, rhinoceros prints predominate among those of the
large animals (Tables 5A and B). At L1 site, all rhinoceros prints
have a northwest orientation, while at L2 site some trackways
head northwest and others toward the east. Raindrop imprints
are numerous at site L1.
Attempts to construct Laetoli mammalian paleoguilds based
on footprint identification produced 11 mammalian and one
avian family. These families are: Hyaenidae, Elephantidae,
Leporidae, Bovidae, Giraffidae, Rhinocerotidae, Bovidae, Cer-
copithecidae, Felidae, Equidae and Numididae. We were able
to tentatively identify tracks made by seventeen different types
of animals and birds: giraffes, roan antelopes, gazelles, guinea
fowls, rhinoceroses, buffalos, elephants,baboons, hyenas, lions,
rabbits, dik-diks, oribi, hartebeests, elands, zebras and the now
FIG. 5. (A) Photograph showing the eroded Footprint Tuffs at Site C, Locality 7 before conservation efforts. (B) Photograph showing the boulder-column
supporting the heavily eroded Footprint Tuffs at Site C. (See Color Plate XVIII)
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PLIOCENE ANIMAL TRACKWAYS AT LAETOLI 173
TABLE 5
List of identified animal prints/per taxon at Sites L1 and
L2.
Identifiable species
No. of
identifiable
prints
% of total
identified prints
A. Site L1:
Lagomorph 15 25.42
Madoqua 15 25.42
Rhinoceros 14 23.73
Lion 1 1.70
Guinea Fowl 10 17.00
Zebra 3 5.08
Indeterminate 1 1.70
Total 59 100
Site L2:
Elephant 4 13.30
Rhinoceros 18 60.00
Guinea Fowl 6 20.00
Hyena 2 6.70
Total 30 100
extinct bovid species of Simatherium kohllarseni. Overall, rabbit
and dik-dik prints were the most numerous, followed by guinea
fowl, hyena, rhinoceros, elephant, giraffe and gazelle of varying
sizes.
The two main processes responsible for the footprint
destruction at Laetoli are of natural and anthropogenic nature.
Natural processes include erosion and weathering mainly caused
by rain and wind. Also a series of fractures composed of
carbonate in-fills as well as tree roots were noted at almost
all sites. Water erosion occurs mainly during the wet season and
heavily water-worked and eroded tuffs are commonly present.
Wind erosion, especially during the dry season (May throughout
August) is common at Laetoli, and its effects can easily be
recognized on exposed tuffs. Anthropogenic agents include
livestock herding and scouring for water during the rainy season.
The Maasai who live in the area practice pastoralism and drive
their cattle over the exposed tuffs on a daily basis. The animal’s
hooves over time cause considerable damages to the footprints.
THE ANIMAL TRACKWAYS AS ECOLOGICAL
SNAPSHOTS AT LAETOLI
Past paleoecological studies at Laetoli focused predomi-
nantly on faunal remains, particularly those of fossil ungu-
lates, fossil pollens and paleosols. The ecological information
available from the animal trackways has not been an im-
portant component of any past environmental reconstruction.
For example, Hay (1980) used fossil faunal assemblages to
postulate that Laetoli’s Pliocene environs closely resembled
open country savanna similar to modern environments in the
modern Serengeti Plains. Bonnefille and Riolett’s (1987) study
using fossil pollen also supported this view. Harris (1985), on
the other hand, proposed a closed habitat of mixed forest for
Pliocene Laetoli. Other studies using similar evidence have
come to different conclusions. Gentry (1987) suggested that
Laetoli paleolandscapes were composed of brush or thorny
shrub habitats contra to Denys (1987), who found evidence
for wooded brush/savanna grasslands. Most recently, a study
of bovid limb morphology from Laetoli fauna conducted by
Musiba (1999) and Musiba and Magori (2006) indicate that
Pliocene Laetoli was a mosaic environment composed of
grassland, light cover and galleries of woodland, much like
the modern Tarangire National Park. The ecological snapshot
that the trackways provide can enhance our understanding
of Laetoli’s past environments and allow testing of different
ecological hypotheses.
Preliminary analyses of the presence and absence of terres-
trial mammalian guilds at Laetoli (Table 6) and their preferable
habitats (Table 7) indicate that Laetoli landscape 3.56 Mya
was very mosaic and differed significantly from the present
Serengeti landscape. The presence of Simatherium Kohllarseni,
Madoqua, giraffe, and roan antelopes strongly indicate the
existence of closed habitats characterized by open woodlands,
wooded grasslands and seasonal floodplains. Furthermore, the
presence of Guinea fowls, rhinoceros, buffaloes, baboons,
hyenas, Madoqua, hartebeests and elands suggest that Laetoli
was mosaic, characterized by galleries of trees, open grasslands,
woodlands, shrubs and thickets.
As predicted, the types of animal tracks we found are similar
to those that Mary Leakey’s team uncovered (Leakey, 1987). In
fact, she found prints made by all of the same animals that we
did. However, Mary Leakey also found tracks made by animals
that we did not find, including Struthianidae, Hominidae and
Suidae as well as Hipparion and Chalicothere prints. Our limited
discoveries, in comparison to Leakey’s team, may be the result
of our short field season and our focus on conservation rather
than on exploration for new sites.
Working under the assumption that habitat preferences of
Pliocene animals at Laetoli would have been similar to the
habitat preferences of their extant counterparts, we are able to
construct general habitat preferences for each inferred animal
represented by prints in the footprint tuffs at Laetoli (Table 6).
Extant counterparts of most of the animals represented by
tracks in the footprint tuffs prefer to live in areas where trees
are present rather than in areas of open savanna grassland. For
example, the predominance of Madoqua (Dik-dik) prints is in-
dicative of a mosaic environment (Musiba, 1999). Furthermore,
Madoqua prints are common at Laetoli and were found at four
out of the six sites we studied, thus indicating that patches of
woodlands might have existed at Laetoli during the Pliocene.
The presence of bovids, especially elands and buffalos as well as
giraffes, and Simatherium kohllarseni also indicate that Pliocene
Laetoli consisted of several different micro-habitats. If the
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174 C. M. MUSIBA ET AL.
TABLE 6
List of reconstructed Laetoli mammalian paleoguilds with
number of identifiable prints/taxon.
Identifiable species
No. of identifiable
prints
% of total
identified prints
Elephant 39 1.18
Lagomorphs 1450 43.91
Madoqua 1449 43.88
Buffalo 12 0.36
Giraffe 16 0.50
Rhinoceros 41 1.24
Gazelle 17 0.51
Hartebeest 11 0.33
Roan Antelope 11 0.33
Hyena 59 1.80
Guinea Fowl 141 4.27
Aves indet. 3 0.09
Simatherium
kohllarseni
50.15
Baboon 10 0.30
Carnivore indet. 15 0.45
Lion 3 0.09
Eland 4 0.12
Zebra 5 0.15
Indeterminate 11 0.33
TOTAL 3302 100.00
habitat preference of modern animals is a reliable indicator
of past habitat preferences, then Pliocene Laetoli consisted
of a variety of habitats including open grassland and wooded
galleries (see also Musiba, 1999).
CONSERVATION EFFORTS ON THE ANIMAL
TRACKWAYS AT LAETOLI
The Tanzania Field School has conducted a pilot conservation
project at site 7 for the past several years. The goals of this
project include:
1.) the preservation and documentation of recently exposed
animal tracks,
2.) identifying the major erosional forces operating at the site
and initiating efforts to reduce them, and
3.) encouraging the involvement of local communities in site
preservation.
The major erosional forces operating at this site are similar
to those at other Laetoli sites namely, seasonal rain water,
livestock, and tree roots. However, the seasonal rains present
a specific problem at this site. A parapet constructed by Mary
Leakey to divert seasonal run-off from a portion of the site is in
disrepair. During the rainy season, water appears to flow from
the parapet to lower areas of the site. This channeling of the
water into a relatively narrow area has resulted in a scoured-out
streambed exposing several tuffs with animal tracks. Based on
our observations over the past five years, the animal tracks in
this section of the site are eroding rapidly.
In conjunction with the Tanzanian Antiquities Department,
and with the consultation and permission of local authorities and
TABLE 7
Animals and their reconstructed habitat analogies.
Animal Preferred Habitat
Giraffe Open woodlands, wooded grasslands, seasonal floodplains
Roan antelope Wooded grassland—need tree clumps for cover
Gazelle Savanna grassland
Guinea fowl Dry areas with more or less tree cover, shrub, and bush
Rhinoceros Edges of thickets and savannahs with short woody growth
Buffalo Savanna with patches of thicket, reeds, or forest
Elephant All vegetation types, changes with season and amount of vegetation available
Baboon Needs trees for survival; woodland/savanna
Hyena Dry acacia bush, open plains, but present in wooded country
Lion Savanna and ecotone, but not closed forests and dry deserts
Lagomorph Grassland or rocky grassland
Madoqua Never seen far from cover; mosaic (Musiba 1999)
S. kohllarseni Closed cover conditions, including forest galleries
Oribi Wooded grassland
Hartebeest Ecotone between wood or scrub and open grassland
Eland Savanna +woodland
Zebra Bush/grass mosaic
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PLIOCENE ANIMAL TRACKWAYS AT LAETOLI 175
Maasai people living in surrounding areas, several conservation
projects were initiated to reduce erosion and document a sample
of animal tracks exposed in the streambed. Tanzanian teachers
(both high school and elementary school) and local people par-
ticipated in all aspects of the conservation projects. Over the past
several years, budget and time considerations limited our efforts
to small projects that could be completed within a few weeks.
Seasonal water flow into the streambed was found to be the
major source of erosion of the exposed tuffs. To reduce water
flow into this area, loose boulders were positioned along the
parapet in the area of disrepair. A permanent solution should
include a hydraulic assessment of the immediate area and
incorporate the needs and lifestyle of local populations. While
seasonal rains scour the surface of exposed tuffs, tree roots are
undermining both unexposed and exposed tuffs.
Acacia trees grow in profusion around the streambed. The
majority of trees appear to be young with trunk diameters of less
than three centimeters. Careful removal of topsoil at the edge
of the streambed in two 3 × 3 meter areas was undertaken to
identify the extent of root damage to the underlying tuffs (Fig.
4). One clearing was made near a mature tree while the other
was in an area of scrub brush. Several roots measuring over two
centimeters in diameter were found to be embedded in the tuffs
in each area. The embedded roots caused uplift, cracking and/or
complete erosion of areas of the tuffs. Before the clearings were
re-covered with topsoil, the roots were cut and several layers of
burlap were placed over the tuffs’ surface to inhibit further root
expansion. The availability of seasonal water and the shade of
a few mature acacia trees draw both wild and domestic animals
to the site. However, as their hooves scrape the tuffs’ surface,
they damage the ancient animal tracks. The importance of the
site and its erosional problems were discussed with the elders
of several local Maasai villages. An agreement was reached
about protecting the site. Local Maasai were hired to cut young
acacias and position them as a livestock barrier around the site.
The local people then agreed to monitor the site and to make
repairs to the barrier as needed. In addition to protecting the site
from livestock, the removal of many of the young acacia trees
from the site, may reduce the extent of root damage to the tuffs.
In order to document the site, photographs and general
information about the animal tracks continues to be collected.
While numerous, the animal tracks in the streambed exhibit
various stages of erosion. Due to the great number of exposed
tracks and the time limits of this project, only a small sample of
tracks were documented by measuring their maximum length,
width and depth, as well as their orientation and their association
with other tracks. In addition, casts were made of specific
tracks using a silicone-based material that lifts easily and is
nondestructive to the matrix. Duplicates of the casts were given
to Tanzania’s Antiquities Department. The casts and other data
we collected enhance the documentation of this site which may
disappear due to erosion.
Perhaps the greatest issue in terms of conservation is the
lack of understanding of the paleontological and paleoecological
FIG. 6. Photographs showing the progressive weathering of the baboon
footprint at Site C. Locality 7. (A) Photo taken during the 2002 field season.
(B) Photo taken three years later during the 2005 field season. (See Color Plate
XIX)
importance of the animal tracks. Clearly the current unchecked
state of deterioration of this rare and rich paleontological
record will result in its rapid disappearance (Fig. 6). However,
there are several courses of action that the custodians of these
treasures could implement as part of a long term conservation
solution. Natural agents are to some extent impossible to control.
Nevertheless, if certain conservation efforts can be implemented
then we may expect to see a decrease in the deterioration of these
important indicators of the ancient environment. For example,
to combat water-based erosion, water diversion structures like
ditches could be built near the exposed footprint tuffs. Such
structures could impact the Maasai living in the area, as they may
be forced to find new trails along which to drive their livestock.
Therefore, such actions would require Maasai participation in
decision making in conservation of Laetoli in general.
As our conservation project shows, the local Maasai can
play important roles in site conservation. To maintain sites, they
could weed out seedlings that have taken root on the exposed
tuffs. They could also cut down trees like those at the hominid
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176 C. M. MUSIBA ET AL.
footprint Site G at Locality 8 that have already punched through
the tuffs. This would prevent them from destroying more of
the tuff as they continue to grow. Tree stumps could be treated
chemically to avoid damage to the tuffs.
Conservation experts who worked on the hominid footprints
did cut and remove Acacia roots using mini powered tools
and surgical instruments. Similarly, the same remedy could be
implemented for the animal trackways at Laetoli. Loosened
tuffs could be strengthened by applying soil consolidants before
removing the roots (Agnew and Demas, 2000). Furthermore,
a monitoring program as part of a comprehensive long-term
conservation program could be established in collaboration
between the local Maasai, archaeologists, and the Department
of Antiquities in Dar es Salaam.
In addition, an educational program could be implemented
which could alleviate some of the anthropogenic destruction of
the footprint tuffs. For example, as we have done, the Maasai
who live in the area could be involved and educated about
the importance of the site. Working in collaboration with the
Antiquities Department, the Ngorongoro Conservation Area
Authority and local village governments, an outreach program
can be established that will include and inform the local Maasai
about the importance of Laetoli. The animal trackway sites
could potentially be used as a cultural heritage attraction that
could bring in revenues to the community. It is clear that a
major conservation effort is required to preserve the animal
trackways. However, successful conservation will require the
involvement of local people and the development of projects
which are compatible with their lifestyle.
CONCLUSIONS AND FUTURE DIRECTIONS
Major mammalian radiations, including the hominini linage,
have been influenced by global climate shifts. However, the
extent of such climate shifts and the subsequent ecological
changes on the African content are still not very well understood.
Laetoli, the only upland Pliocene paleontological site in Sub-
Saharan Africa, sports perhaps some of the most important
clues that might assist us to fully understand the effect of
Pliocene climate shift and turnover pulses. Laetoli’s animal
trackways are of great importance in that they contain snapshots
of time-averaged paleoecological events that may help us
understand high-fidelity ecological changes that are usually
hard to discern from biostratigraphic evidence. Therefore, a
paleoenvironmental reconstruction using the ichnofossil record
available at Laetoli is necessary in understanding trends
associated with human evolution during the Pliocene in East
Africa. This study, which we consider as preliminary in nature,
enhances our understanding of Laetoli’s ancient landscape
through the use of mammalian paleoguilds presented in the
ichnofossil record.
Our preliminary results, based on the animal tracks we
investigated, indicate that sites were dominated by Madoqua
(Dik-dik), lagomorpha, large to medium-sized bovids, giraffes,
carnivores, primates and elephants. The diversity of animals
represented in the footprint tuffs suggests that the landscape
of Pliocene Laetoli consisted of a variety of microhabitats.
Therefore, our results are consistent with inferences that Laetoli
was a mosaic landscape during the Pliocene (Musiba and
Magori, 2006; Harrison, 2005; Andrew, 1989).
This study demonstrates the potential of ichnofossils as eco-
logical indicators of time-averaged depositional environments
in paleontological sites. However, our results are limited by
our small sample size. Because of budget and time limitations,
we studied only six out of the 18 localities that contain animal
trackways reported by Mary Leakey and her co-workers in 1987.
Furthermore, the inherent assumption that Laetoli animals 3.8
million years ago may have preferred similar habitats to their
extant relatives may be open to question and further testing.
While we are aware of these limitations, the data provided
can enhance future studies of Laetoli’s paleoenvironments.
Future research is planned that will include analysis of bovid
limb elements and a more detailed analysis of the animal
tracks. The importance of Laetoli to our understanding of
human evolution compels consideration of the ichnofossil
record in reconstructions of its paleoenvironments. Also, the
ecological significance of the animal trackways warrants a major
conservation effort to preserve them.
ACKNOWLEDGEMENTS
We would like to thank our academic institutions for
facilitating the establishment of the field school and the semester
abroad program at Laetoli. We are particularly indebted to
our students who shared their field school experiences with
us, the Associated Colleges of the Midwest (ACM) for the
establishment of the Semester Abroad Program in Tanzania,
Dr. E.B. Chausi and the entire personnel at Ngorongoro
Conservation Area Authority (NCAA) for their understanding
of the scientific needs for such programs in the NCAA, and for
their invaluable time and contribution that shaped this study.
We also thank our Tanzanian colleagues, Ferdinand
Mizambwa, Felix Ndunguru, Godfrey Ole Moita, Said Killindo
and O.S. Kileo for comments, their help in field logistics and
field assistance during our summer field work at Laetoli. We are
very grateful to the Tanzanian Ministry of Tourism and Natural
resources and the Antiquities Department. We are also very
indebted to Mr. Donatius Kamamba for issuing the Antiquities
excavation license and to the doctor in-charge at Endulen
Hospital with his entire staff for the health related support to
our students and field staff.
We extend our thanks to the Lutheran Bishop of Dodoma,
Rev. Dr. Peter L. Mwamasika and Dr. Abel Nkini for their en-
couragement and transport-related logistic supports in Tanzania.
This project was funded by the Werner Gren Foundation (Gr.
5980), the Connecticut State University System, the ACM, the
National Geographic Society and a generous grant from Dr.
Melissa K. Stoller to Dr. Charles Musiba. We thank the editors
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PLIOCENE ANIMAL TRACKWAYS AT LAETOLI 177
of this volume and the two anonymous reviewers for providing
insightful comments from which the quality of this manuscript
benefited tremendously.
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