Hominid Species Time Line

Page 6

Ardipithicus ramidus
@ 4.4 to 4.2 million years ago [see also Ardipithicus ramidus kadabba, next page.]

Discovered in 1994 at Aramis, just south of Hadar in Ethiopia by an expedition from the University of California at Berkeley, this species appears, on anatomical grounds, to be ancestral to A. afarensis.  Its teeth and other bones are somewhat more chimp-like than "Lucy's" (A. afarensis).  With thinner dental enamel than other hominids, this species seems adapted to a soft diet.  Unfortunately, most of the remains of this species consist of teeth and jaw bones, with very few other cranial bones and no leg bones.  Eventually, the partial remains of 17 individuals were recovered.

 The species name for this creature is ramidus, after an Afar word (one of the Ethiopian languages) meaning "root."  While this species was originally classified as an australopithecine, the 17 individuals found in 1994 exhibit significant differences from other members of that genus.  Accordingly, discoverer Tim White proposed the new genus name, Ardipithicus (from the Afar word for “ground” and the Greek word for ape):  hence, the name means  “root or base apes.”

 From the bones originally discovered, it was not possible to determine if Ardipithicus ramidus was bipedal.  Scholars have been able to infer from contextual evidence, however, that his species lived in a forest environment.  It was long believed that the earliest hominids must have evolved in a savannah environment, but such has not proved to be the case.  A. ramidus lived in an upland environment @ 1,500 meters above sea level in a cool, well watered forest environment.  Elephants, rhinos, horses, and woodland antelope shared their territory, which experienced frequent volcanic episodes.

References:

http://www.archaeologyinfo.com/

Ardipithecus ramidus on TalkOrigins.org