He discovered the Hadar formation, recognized its potential importance to paleoanthropology and founded the International Afar Research Expedition (IARE).

This enabled co-director Donald Johanson to discover an early hominin fossil, the 3.2-million-year-old Australopithecine Lucy in the Awash Valley of Ethiopia's Afar Depression.

Taieb died on 23 July 2021,[citation needed] and was survived by his wife Ingrid and their two sons, Laurent and Jean Marc.

In 1972, Taieb founded the IARE, and was present two years later when Donald Johanson discovered fossil fragments of Lucy.

Along with co-directors of IARE Johanson and Yves Coppens, Taieb played a key role in identifying the geology and history of the Afar Region.