Where is laetoli in relation to olduvai gorge

The steep ravine is about 30 miles A river cuts through several layers to form four individual beds, with the oldest estimated at about 2 million years old. At Laetoli, west of Ngorongoro Crater, hominid footprints are preserved in volcanic rock 3. Three separate tracks of a small-brained upright walking early hominid. Australopithecus afarensis, a creature about 1. Imprints of these are displayed in the Oldupai museum. Excavations, mainly by the archaeologist Louis and Mary Leakey, yielded four different kinds of hominid, showing a gradual increases in brain size and in the complexity of their stone tools.

The most important find include Home habilis, Zinjathropus and the Laetoli footprints. Buses , Flights , Charter. Email Website. Thickness 6—23 cm; sharp subhorizontal limit. Thickness 4—5 cm; sharp limit marked by a thin planar void.

Moderately well-sorted anhedral to subhedal, subrounded to subangular, medium to fine sand-size light grey to greenish grains; white microcrystalline cement. Common animal and three hominin tracks. Tracks and trackways of mammals, birds and insects, as well as raindrop impressions, are recorded from 18 sites at Laetoli, named alphabetically from A to R.

Sites from A to P were listed and geographically located by Leakey b , who also described in detail the ichnological record of the most important exposures.

Sites Q and R were discovered and described by Musiba et al. More than 11, single footprints are recorded from Sites A—R. A total of footprints of mammals excluding hominins and birds Table 1 were recorded during the September field season. The prints were carefully cleaned using soft brushes to reveal detailed features, measured, photographed, traced, mapped and identified in a preliminary study.

Mammal tracks — mostly of small and medium-size bovids — are very abundant in M10, L8 and M9 and occur less frequently in TP2. Their size 30—40 mm long and 20—36 mm wide and morphological features suggest that most of them can be ascribed to the genus Madoqua Figure 2 and Figure 2—figure supplement 3. It is very difficult to distinguish the footprints of Madoqua -like bovids from lagomorph footprints because of their very similar morphology and size Leakey, a.

Consequently, we decided to ascribe to Lagomorpha only trails that clearly include at least four footprints arranged in the normal hare gait pattern, i. Each single trail i. The above-mentioned assemblage of terrestrial mammal and bird footprints suggests that the local palaeoenvironment was characterised by a mosaic of dry tropical bushland, woodland, open grassland and riverine forest similar to the extant one.

The morphology of the S1 tracks can be described in detail, but unfortunately the only preserved track of S2 shows an abnormal widening of the anterior part. This enlarged morphology is possibly due to a lateral slipping of the foot before the toe-off; alternatively, it could be due to taphonomic factors as a thick root crossing the footprint longitudinally may have altered its original morphology.

No clear distinction among the toes is visible. The adducted hallux extends more anteriorly than the other toes in all visible footprints. These marks were possibly left by the heel shuffling on the ash before being firmly placed into the soil. The two latter features were also recognised in some of the G2 prints Robbins, and suggest that the feet were probably lifted above the ground at a low oblique angle.

The depth distribution pattern indicates that the weight transfer of S1 was similar to that described for G1—3 Robbins, : starting from the heel, the weight was transferred along the lateral part of the foot note the steep slope of the lateral wall of the tracks compared to that on the medial side up to the distal metatarsal region, and from here to the toes. This may suggest a somewhat asymmetrical walking, in which the weight was sometimes loaded on the anterolateral part of the foot before the toe-off.

Alternatively, this pattern may be indicative of a rotation of the upper body during the gait Schmid, The empty circles and squares indicate the position of the targets. The main dimensional parameters of the tracks at Site S are presented in Table 2 the single measurements are explained in Materials and methods. Dimensional parameters measured and derived from the Laetoli Site S tracks and stature and body mass estimates for S1 and S2. See Materials and methods for details.

Speed estimates for S1 and G1—3 were computed starting from stride length Figure 3 see Materials and methods. The obtained values Table 3 show that these hominins were all walking at similar low speed about 0. Data and estimates for the five Laetoli track-makers from Sites S and G. Limited to S1, mean values, standard deviation and range are provided.

For walking speed and relative speed, values outside the brackets are based on the method of Alexander , those inside the brackets are based on the method of Dingwall et al. The average length of the tracks in the S1 trackway is mm range — Lower values were measured for the three individuals at Site G.

The average lengths are mm for G1, mm for G2 and mm for G3 Leakey, ; Tuttle, Table 3 , although a digital analysis-based study Bennett et al. The main metrical features of the S1 and S2 tracks footprint length and width, step and stride lengths are larger than the G1—3 equivalents Table 3. It must be pointed out that stature and body-mass estimates obtained by linear regressions from modern humans Tuttle, ; first method by Dingwall et al. Consequently, we focused our interpretations on the more appropriate predictions inferred from the relationship between foot size and body dimensions in Australopithecus second method by Dingwall et al.

The data in Tables 2 — 3 indicate that stature and mass estimates for S1 and S2 about cm and Site S is situated on an almost level or very gently dipping surface, situated at the foot of the left southern side of the Garusi River valley. Site G is situated about m to the north, on the same surface but 1.

Several shallow gullies dissect this surface, producing a complexly terraced morphology: consequently, there is no observable stratigraphic continuity between the two sites. However, the gullies put into light about 2—3 m of the underlying sequence, whose units are horizontally layered and characterised by almost constant thickness.

Only a shallow depression elongated E-W can be observed between the sites; this is probably an ancient erosion channel filled by a constant thickness of the Site S footprint-bearing tuff.

Even if the area of possible outcrop of the Footprint Tuff on gully sides close to Site S is covered by debris, the correlation between G and S is in general straightforward. All previous literature describing the original stratigraphic setting at Laetoli Leakey and Hay, ; Hay and Leakey, ; Hay, indicates that the Footprint Tuff can be divided into two main units — the lower and the upper one — which can be subdivided into 14 and 4 sublevels, respectively. Footprints occur on several sublevels of each unit all over the Laetoli area: eight within the lower one mostly on sublevel 9 and on the topmost sublevel 14 , and two within the upper one sublevels 1 and 2.

Leakey and Hay , pp. Later, Hay and Leakey , p. Eventually, Hay , pp. Although the stratigraphic descriptions above are very accurate, they do not provide details about the eye-scale characteristics of the tuffs, i. The Site S sequence does not fit the aforementioned descriptions perfectly, at least not within the observed area, which is rather narrow. The grey augite-rich tuff of Site S largely matches the description of the Augite Biotite Tuff described by Hay , p.

Regarding the Footprint Tuff, the upper unit corresponds to Site S Laminated Grey Tuff, but the sublevels here are layered rather crudely, whereas the most evident sedimentary structure is a very fine and almost continuous lamination, which makes the subdivision rather problematic.

Energy-sorting of denser grains is apparently a relevant aspect of the depositional processes. The top sublevel is rather thicker than the others and somewhat whitish instead of greyish, as apparent also in Localities 6 and 7.

Consequently, lateral variability can also be expected within the sequence of the Footprint Tuff, even if the involved volcanic depositional processes were rather uniform over a wide area around Laetoli and gave the whole sequence a remarkably homogeneous aspect throughout its outcrops. The correlation between Site G and Site S cannot be absolutely undisputable, at least for the time being, because the original profile could not be examined directly.

However, the geological and morphological setting of the area, as well as the characteristics of the newly exposed sequence, indicate with a very good margin of confidence that the newly discovered tracks belong to the Footprint Tuff.

To provide a more accurate correlation within the Footprint Tuff, we observe that the Site S tracks were printed on the uppermost level of the Finely Layered Grey and White Tuff unit 4 in the description provided in this paper , which corresponds to the lower subunit of the Footprint Tuff.

The lithological change to the overlying subunit is very evident and marked by a sharp surface, often underlined by a thin crack. However, because of the aforementioned dissimilarities, it is not possible to assess with reasonable confidence whether this stratigraphic position also corresponds to the top of level 14 in the standard sequence Hay, , p.

Our results show that no matter which method is employed to estimate stature and body mass see Material and methods , the two individuals S1 and S2 were taller and had a larger body mass than the G individuals. The estimated about cm stature of S1 is quite remarkable, exceeding G2 by more than 20 cm Table 3. In order to contextualise the australopithecine and early Homo stature estimates and range of variability obtained from the footprints within a broader picture Figure 12 , and to compare them with a larger sample, we extended our analysis to consistent data based on skeletal elements, namely femurs see Materials and methods for details.

Figure 12 shows the estimated stature of australopithecine and early Homo individuals by species between 4. The predicted stature of S1 exceeds any australopithecine: a mean value of cm was estimated for the large Au. The stature of S1 falls within the range of modern Homo sapiens maximum values; it also fits the available Homo erectus sensu lato estimates based on fossil remains Ruff and Walker, and on footprints Bennett et al.

At the same time, the 41 to 48 kg body mass range estimated for S1 Table 3 falls easily within the range of male Au. These results extend the dimensional range of the Laetoli track-makers and identify S1 as a large-size individual, probably a male Plavcan, ; Grabowski et al.

Solid symbols or crosses in bold refer to stature estimates based on actual femur length; open symbols refer to stature estimates based on estimated femur length, in turn based on femur head diameter.

For Laetoli and Ileret, stature estimates are based on footprint length see Materials and methods. For Laetoli, Ileret and Woranso-Mille, the average value and range of predicted stature are shown. See Supplementary file 5 for details. These findings provide independent evidence for large body-size individuals among hominins as ancient as 3. Consequently, we may emphasise the conclusions by Grabowski et al.

Thus, our results support a nonlinear evolutionary trend in hominin body size Di Vincenzo et al. The identification of large-size individuals among the australopithecines — i. The most parsimonious option is that sex and age of the hominins represented at Site G cannot be determined, as subadult individuals could possibly be present among them.

However, the body-mass estimates suggest some observations as G1 and G3 fall within the range of putative Au. All of these individuals are definitively smaller than the body mass calculated from the S1 tracks. A possible tentative conclusion is that the various individuals represented at Laetoli are: S1, a male; G2 and S2, females; G1 and G3, smaller females or juvenile individuals. Evidence for either marked or moderate body-size variation in Au.

The new estimates for the Laetoli individuals indicate an even more marked variation in body size within the same hominin population, at 3. Consequently, the combined records from Laetoli and Hadar suggest that large-bodied hominins existed in the African Pliocene for over , years, between 3. At the same time, these data contrast with the hypothesis of a temporal trend of body-size increase among Au.

The impressive record of bipedal tracks from Laetoli Locality 8 Site G and the new Site S may open a window on the behaviour of a group of remote human ancestors, envisaging a scenario in which at least five individuals G1, G2, G3, S1 and S2 were walking in the same time frame, in the same direction and at a similar moderate speed. This aspect must be evaluated in association with the pronounced body-size variation within the sample, which implies marked differences between age ranges and a considerable degree of sexual dimorphism in Au.

Significant implications about the social structure of this stem hominin species derive from these physical and behavioural characteristics, suggesting that reproductive strategies and social structure among at least some of the early bipedal hominins were closer to a gorilla-like model than to chimpanzees or modern humans. Finally, the discovery reported here opens up the intriguing possibility that additional hominin trails may also occur in the area between Site G and Site S.

Extended geological observations were carried out in the Laetoli area, mostly in the nearby historical Localities 6 and 7 Leakey, b , in order to compare the sequences exposed there with the new Site S sequence and to assess its stratigraphic position. Unfortunately, correlation with the stratigraphic sequence of Site G Locality 8 is impossible because this historical site is completely covered by protection features and cannot be used for direct comparison.

In Site S, field observation and detailed sequence descriptions were carried out on excavation profiles following the standard formalized by Catt Basic observations on grain size, shape and mineralogy were carried out in the field using a 10x magnification hand lens. Higher-detail analyses were carried out in the laboratory, using a standard Leica stereomicroscope.

The survey of the new tracks at Site S in September was focused on obtaining 3D models for documentation and morphometric analysis. The survey method is the Structure from Motion technique, an image-based process supported by in situ topographic measurements.

This technique was chosen because of its technical advantages relatively short time of data acquisition and processing; light and handy equipment; reduced costs and excellent results in terms of resolution. The equipment used in the fieldwork is a DSLR camera with When necessary, the camera was mounted on a 4 m-long telescopic rod.

A measuring tape and a water level were used for the measurement of the control points i. Considering the small size of the surfaces to be detected, this measuring technique provided very high accuracy results. IV of June 5, After the excavation, the 52 targets of the control point system were immediately positioned: 14 in L8, 10 in M9, 14 in TP2 and 14 in M Each test-pit was entirely surveyed at lower resolution and then detailed 3D models of some inner portions single prints or groups of close prints were acquired Figures 4 — 6.

We positioned four perimeter targets on the ground at the corners of each test-pit, and four inner targets around each sub-area surveyed in detail.

The following list shows the target IDs in relation to the four test-pits and selected areas AF: animal footprints :. In order to optimize the timing of the fieldwork, we decided not to model in detail some of the hominin tracks, i. One of the goals of the field school is to make this course one of the most interesting and valuable learning experiences to students. Meals at the field site are included in the price program, except for the period that students will spend in transit traveling to and from the field school location as well as during excursions.

The field school hires two professional cooks who have over 15 years of paleoanthropological field-related cooking experiences. One of the two Tanzanian cooks worked with the late Dr. Leakey at Olduvai Gorge and Laetoli in The other is a retired full-time chef who worked with an international shipping company.

Our field school chefs have culinary expertise ranging from; African and European dishes to Chinese cuisine. The field school has its own cooking facility at the Aguirre-Mturi Field Research Station and a mobile cooking facility at Laetoli that includes an efficient charcoal and gas stoves, all kitchen ware, drinking water filters, dining tables and chairs and a deep-well water hook-up that is usually connected to the Endulen hospital water supply system.

The field school has a mobile storage for dried food. The supermarket not only sells local dried food but also American and European imported food such as cereals, canned meat, pasta, and concentrated soft drinks. The food in the field is usually prepared on an open air fire.

As part of the field school preparation, students must visit a travel clinic or their physician and receive the appropriate vaccination and malaria medication several weeks before departure to Tanzania. Students will be advised to keep their vaccination record together with their passport at all times while in Tanzania and leave photo copies of their important documents including passport in their suitcases.

Any medications that are needed on a regular basis should be purchased before departure to Tanzania. Through our first five years of field school, we have forged a partnership with Endulen hospital, which is the only hospital in the Ngorongoro Conservation Area, serving a population of at least 51, scattered in an area of some sq.

The hospital is 34 Km Southwest of the NCAA authority Headquarters and it has a permanent health personnel of about 50 — 60 persons including a medical officer and two clinical officers as well as nurses, lab specialists and other hospital supporting personnel. This hospital serves as our field school health hub and provides us with running water on a co-sharing cost agreement.

However, major medical needs may require evacuation to referral hospitals in Arusha, Mwanza or Nairobi. Therefore, students should make sure that their health insurance will cover medical evacuation if needed. Although students are responsible for their airfares and travel arrangements to and from Kilimanjaro, Tanzania, based on our past experiences, we strongly recommend that students coordinate with the program co-directors when making travel arrangements.

The field school co-directors will provide the students with information on the International airport in-country and the final destination for the travel. The different kinds of hominids found here show a gradual increase in brain size and in the complexity of their stone tools. Made by feet little different than our own, they proved conclusively that these creatures stood and walked upright bipedally with a human like stride a million years before the invention of stone tools and the initial growth in hominin brain size.

It is undoubtedly one of the most astounding and important scientific discoveries of our time. The 3.