A skeleton believed to be the fossil of the human oldest ancestor that lived 4.4 million years was discovered by a group of paleoanthropologists led by an American anthropologist, Tim D. White, in 1994.
Ardipithecus ramidus, as named, was discovered along the West of Awash River, Afar region, Aramis, in Ethiopia. The fossil’s name was gotten from the Afar language – Ardi, which means ground or floor, while Ramid means root, and Pithecus, a Greek word for Ape.
Ardi, as nicknamed, shared a phylogenetic relationship with Australopithecus, as both had a non-honing canine tooth, a postcranial character relating to the facultative bipedality, and a foreshortened cranial base.
Unlike other diagnosed fossils, Ardi’s skull was resting atop her spinal column, so she was believed to be bipedal when walking on the ground but quadruped while on trees, with her big toe splaying out from her foot for a comfortable grasping of trees. She weighed 51 kg, and her height was estimated to be about 117 to 124 cm. Unlike modern humans, she had a prognathous face, the tarsal and tibial lengths show a leaping ability that lacks vertical climbing or knuckles walking.
Ardi had a long lumbar vertebral series and lordosis due to her bipedality. However, the legs were not totally joined with the torso, which was believed to rely mostly on her quadriceps for climbing. Her upper pelvis was short.
Ardipithecus ramidus was believed to be omnivores according to a Carbon-isotope study of the teeth. The enamel on the teeth was neither thin nor thick, so it was thought they survived on meat, fruit, and plants. The front teeth were believed to have been used frequently for clamping and pulling of edibles.
Over the years, over 100 fossils of Ardipithecus have been discovered in Kanapoi, Lothagam, Tabarin, and northern Kenya.
The fossil (Ardi or Ara-VP-6/500 as its holotype) consists of 125 pieces was an incomplete skeleton found in 1994, although the jaw and teeth were discovered in 1992. However, due to the specimen’s terrible condition, excavating and researching the structure took 15 years before the fossil was described and published in 2009.
The cranial base of Ardi is short from the front to the back, which proves the head rested on top of the spine. Has a small face, and the ridge above the eye-socket is different from that of a chimp.
Upon Ardi’s death, her remains were believed to were marched into the mud by hippos, which after millions of years, erosion brought the bones to surface, by then it had become so fragile that they were removed and taken along with the surrounding rocks in a lab at Addis before they were carefully disengaged from the rocks with the help of a needle and a microscope while the skull was CT-scanned and repaired by a paleoanthropologist from the University of Tokyo, Gen Suwa.