Fragmentary fossils were first found in the Glib Formation at the Glib Zegdou locality in Algeria and dated to the Early to Middle Eocene, 50 to 46 million years ago. The holotype was an upper left molar.
First described in the journal Nature by Marc Godinot and Mohamed Mahboubi in 1992, Algeripithecus was once widely considered one of the oldest known fossil simian primates, giving weight to the African origins hypothesis for simians. It was originally interpreted as a propliopithecid, but was also seen as a proteopithecid by Godinot in 1994 and as a parapithecoid by Seiffert et al. starting in 2005. Based on the discovery of additional fossil teeth and a maxilla between 2003 and 2009, Tabuce et al. reconstructed Algeripithecus as an azibiid, a group thought to be a type of stemlemuriform, or strepsirrhine primate. According to Tabuce et al., the mandible of Algeripithecus indicates it had an inclined canine tooth, similar to that found in toothcombed primates. Although the anteriordentition of azibiids is unknown, they may have possessed a toothcomb, indicating an ancient stem lineage of lemuriform primates in Africa, possibly descended from an early Asian branch of adapiforms such as a primitive branch of cercamoniines predating Donrussellia. As a result, the African origins of crown strepsirhines is well supported, whereas the African origins of simians has been placed in doubt, possibly giving favor to an Asian origins hypothesis. However, in 2010, Godinot reasserted his view that Algeripithecus was a simian based on its upper molar morphology and hypothesized that this applied to all azibiids, favoring his earlier view that azibiids may be early simians instead of stem lemuriforms. In 2011, Marivaux et al. published an interpretation of recently discovered talus bones of closely related Azibius found at Gour Lazib, which they claimed were more similar to those of living strepsirrhines and extinct adapiforms, not simians, thus reinforcing the strepsirrhine status favored by Tabuce et al. two years earlier. Godinot also cautiously suggested that Dralestes may be a synonym of Algeripithecus based on a blade-like premolar. Alternatively, the second upper molar of Dralestes hammadaensis have been reinterpreted by Tabuce et al. as being the upper fourth premolar of Azibius, and therefore considered Dralestes to be a synonym of Azibius. Specimens of Dralestes are now recognized as being either Azibius and Algeripithecus.
Anatomy and physiology
Like all azibiids, Algeripithecus was a small-bodied primate. Initially thought to weigh, Algeripithecus minutus is now estimated to have weighed between, nearly half the weight of the only other known azibiid, Azibius trerki. It was comparable in size to a hairy-eared dwarf lemur or a brown mouse lemur.
