By Maina Kiarie
First found in the Middle Awash area of Ethiopia by a team led by American paleoanthropologist Tim White in 1994, Ardipithecus ramidus had a small brain, measuring between 300 and 350 cubic centimetres and lived about 4.4 million years ago. Since its first discovery, over 100 fossil specimens have been unearthed alongside faunal remains that indicate they lived in a wooded environment. Canine teeth of this species also indicates very little difference in size between males and females, a feature known as sexual dimorphism.
‘Ardi’ means ‘ground’ or ‘floor’ and ‘ramid’ means ‘root’ in the Afar language, referring to the closeness of this new species to the roots of humanity. The names was devised by White to distinguish it as a new genus from Australopithecus.
A partial female skeleton, known as ‘Ardi’ showed that it moved in the trees using a grasping big toe. The skeleton also showed a shorter and broader pelvis than an ape, indicating that she could walk bipedally (on two feet). The skeleton shows that the female averaged 3 ft 11 inches (120 centimetres) and weighed about 110 lbs (50kg). Males were similar in size (based on the similar size of canines) and it is likely Ar. ramidus males did not compete against each other for dominance.
Ardipithecus ramidus individuals were most likely omnivores, eating a more general diet of both plants, meat and fruit. It is unlikely they ate hard abrasive foods like nuts and tubers. This is deduced from analysis of their teeth. The enamel on their teeth was neither thick nor thin. Thick enamels would mean they ate tough, abrasive foods while thin enamels would suggest they ate softer foods such as fruit. Their enamel thickness is between a chimpanzee and late Australopithecus or Homo species, suggesting a mixed diet. The wear pattern and incisor sizes indicate this species was not a specialised fruit eater also known as a frugivore.