Classifying the footprints

In total 269 human and animal prints were discovered, preserved in coarse ash. Approximately 60% of the prints were human, with 36% of the human prints classified as children’s because of their size. Several types of animal prints were also identified including dogs, big cats and animals with cloven feet, possibly deer, camels or bovids. Several short trails of footprints are visible in some parts of the quarry.

 

  

Left and right human footprints, Toluquilla quarry.	Left human footprint showing the typical figure of eight shape

 

The researchers were able to classify the footprints as human because they demonstrated some unique characteristics, including:

• pedal arches, where foot bones form two perpendicular arches that normally meet the ground only at the heel and ball of the foot. These arches are found only in humans
  
  
• where it is possible to see toe impressions, there is a non-divergent big toe (or hallux) which is about twice the size as its adjacent toe
  
  
• the fact that they have deep heel and ball impressions, encircled by the typical ‘figure of eight’ contours
  
  
• they fall within the size range used for modern Homo sapiens.
  

 

Based on the footprints information, it is estimated that the adult humans were between 117 and 190 cm tall.