Azibiidae is an extinct family of fossil primate from the late early or early middle Eocene from the Glib Zegdou Formation in the Gour Lazib area of Algeria. They are thought to be related to the living toothcombed primates, the lemurs and lorisoids (known as strepsirrhines), although paleoanthropologists such as Marc Godinot have argued that they may be early simians (monkeys and apes). It includes the genera Azibius and Algeripithecus, the latter of which was originally considered the oldest known simian, not a strepsirrhine. Originally described as a type of plesiadapiform (an extinct group of arboreal mammals considered to be a sister group to the primate clade), its fragmentary remains have been interpreted as a hyopsodontid (a type of extinct condylarth), an adapid (an extinct type of adapiform primate from Europe), and a macroscelidid (elephant shrews). Less fragmentary remains discovered between 2003 and 2009 demonstrated a close relationship between Azibius and Algeripithecus. Descriptions of the talus (ankle bone) in 2011 have helped to strengthen support for the strepsirrhine status of Azibius and Algeripithecus, which would indicate that the evolutionary history of lemurs and their kin is rooted in Africa. Likewise, if azibiids are simians, it would support the hypothesis that simians originated in Africa instead of Asia. Azibiids were small-bodied primates, with Algeripithecus minutus weighing between , Azibius trerki weighing approximately , and an unnamed species of Azibius being notably larger, weighing an estimated . Evolutionary history Although the taxonomy is disputed, morphological evidence suggests that azibiids were one of the earliest offshoots of the early primate lineage leading to living lemuriforms, which excluded other adapiform primates. According to Tabuce et al., the mandible of Algeripithecus indicates it had an inclined canine tooth, similar to that found in crown lemuriforms (extant strepsirrhines). Although the anterior dentition of azibiids is unknown, they may have possessed a toothcomb (a specialized dental structure found in lemuriforms), 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 (one of the oldest European adapiforms). However, the uncertainty about the presence or absence of a true toothcomb in azibiids makes it difficult to determine if they are stem or crown lemuriforms. According to Tabuce et al., Azibiids belong to an Afro–Arabian clade of stem lemuriform primates, including successive sister taxa such as djebelemurids (including Djebelemur and 'Anchomomys' milleri)