24 Matching Annotations
  1. Sep 2018
    1. 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).

      Using an analysis of both the footprints and femurs to estimate stature makes the findings more accurate. It appears to the authors that Australopithecus afaransis males were generally of the same stature as early Homo individuals.

    2. Secondarily, stratigraphic relationships can be explored at higher detail, in order to assess whether the tracks of Site S were printed on exactly the same sublevel of the Footprint Tuff as those in Site G. This aspect would mostly concern the behavioural aspects of a hypothetical single group of hominins, but it must be pointed out that extra-fine correlation between outcrops, even in a depositional environment with moderate lateral variability like the Footprint Tuff deposition area, can be affected by major uncertainty.

      It is difficult to determine a relationship between a hypothetical group of hominins because external variables—such as geographic faults and fractures discussed earlier—make these extra-fine correlations generate uncertainty.

    3. Ngorongoro Conservation Area

      The area is protected by the Ngorongoro Conservation Area Authority, an arm of the Tanzanian government. In 2009, the Ngorongoro Wildlife Conservation Act was passed which limited human settlement and subsistence farming in the area, generating some controversy.

  2. Aug 2018
    1. clods deriving from disarticulation of desiccation polygons

      Desiccation polygons are areas bordered by cracks in the mud found in sedimentary rocks and mud flats. Disarticulation suggests that the polygons separated from the mud and formed individual clods of earth or rock.

    2. Small amounts of water were used during the excavation, in order to soften the sediment and darken its hue to better distinguish it from the surrounding tuff. The infill was finally removed by small dental tools, trying not to damage the very thin calcite film covering the original footprint surface (White and Suwa, 1987).

      The degree of fossilization of the footprints varied in different locations. In order to study the shape and structure of a footprint, soil had to be carefully removed from the depression.

  3. Jul 2018