216 Matching Annotations
  1. Mar 2018
    1. Hominin and non-hominin tracks were recognised in four test-pits at Site S, namely L8, M9, TP2 and M10.

      The authors made a series of test-pits in order to follow the predicted direction of the footprints.

    2. lithological

      This refers to the physical characteristics of the rock as observed in an exposed outcrop or in a core sample. Here the authors are referencing differences in the layer of soil overlying the Footprint Tuff.

    3. Consequently, we focused our interpretations on the more appropriate predictions inferred from the relationship between foot size and body dimensions in Australopithecus

      The authors used the size and shape of the footprints to infer body mass, stature, and walking speed for four of the individuals (S1, G1,G2, and G3)

  2. Feb 2018
    1. In this paper, we report a novel set of hominin tracks discovered at Laetoli in the new Site S, comparing it to a reappraisal of the original evidence. The new tracks can be referred to two different individuals moving in the same direction and on the same palaeosurface as those documented at Site G.

      The authors of this study analyzed the new set of footprints found at the Laetoli site. Their goal was to compare their results with earlier work in determining stature, morphology, and degree of sexual dimorphism of the individuals leaving the tracks.

    2. Within-species variability in body size often relates to sexual dimorphism and/or to adaptation to different ecologies

      Traditionally, paleobiologists hypothesized that early hominids exhibited a high degree of sexual dimorphism. This thinking is based on limited fossil evidence and consequently is being questioned by a number of researchers.

    3. orthophotos

      These are typically aerial photos that have been corrected so that there is no distortion. The scale is uniform.

    4. lens geometric distortion

      Close to the optical center of a lens, it is assumed that there is no image distortion or exaggeration of the image. A grid system can be used to determine the distance between points in a distorted image and the actual distance.

    5. distal metatarsal

      Distal means away from the point of attachment or center of the body. Metatarsals are the five long bones in the foot located between the tarsals and toes (phalanges). Thus, as the individual walked, the placement of weight on the foot started at the heel and moved toward the toes.

    6. ursid

      An ursid is a bear.

    7. lagomorphs

      Rabbits, hares, and pikas are classified as lagomorphs.

    8. pedogenised

      Pedogenesis is the process of soil formation. In Test-pit L8, the environmental forces acting to form soil destroyed the fossil footprints.

    9. carbonate dissolution

      Carbonate rock reacts with water that contains dissolved carbon dioxide. This reaction with the slightly acidified water results in the rock being eroded away.

    10. micro-grabens

      Graben is a geological term for a depressed section of Earth's crust. An example would be a river valley created by erosion or a rift valley created through faulting. A micro-graben is a small depression bordered by higher scarps.

    11. extant

      Species that still exist.

    12. morphology

      The study of the external and internal structure and shape of organisms. This would include hominin skeletal structure, size, and foot shape.

    13. stature

      The term refers to how tall a person is when standing upright.