The first specimenO. macedoniensis was discovered by French palaeontologists Louis de Bonis and Jean Melentis in 1977,[3] andO. turkae by Turkish team led by Erksin Savaş Güleç in 2007.[2] For a long time it was considered as similar (synonymous) toGraecopithecus and member of the genusSivapithecus,[4] which more discoveries proved otherwise.
Based onO. macedoniensis' dental and facialanatomy, it has been suggested thatOuranopithecus was actually adryopithecine. However, it is probably more closely related to thePonginae.[5][6] Some researchers considerO. macedoniensis to be the last common ancestor of humans (hominins) and the other apes,[7] and a forerunner toaustralopithecines and humans,[8] although this is very controversial and not widely accepted. It is true thatO. macedoniensis shares derived features with some earlyhominins (such as the frontal sinus, a cavity in the forehead), but they are almost certainly not closely related species.[9]
In 1984, British palaeontologists Peter Andrews and Lawrence B. Martin classifiedGraecopithecus andOuranopithecus as synonyms (same taxon) and treated them as members of the genusSivapithecus.[10][11] However, comparative analysis showed that there is not enough data to support the synonymy.[12]
When moreO. macedoniensis fossils were discovered[13] including part of the skull in the 1990s,[14] it became apparent thatO. macedoniensis andG. freybergi are distinct species. In the light of new data, in 1997, Australian palaeontologist David W. Cameron treatedGraecopithecus as a valid genus based on taxonomicpriority and renamedO. macedoniensis asGraecopithecus macedoniensis.[15][16] However, betterO. macedoniensis specimens were found[17] including a new speciesOuranopithecus turkae from Turkey[18] that warranted separation of the genus.
In addition, a meticulous re-description ofGraecopithecus specimens in 2017 further evidenced thatGraecopithecus is more related to humans than to apes,[19] whileOuranopithecus specimens have strict ape-like characters. Separate genus are therefore continued to be generally adopted.[20][21][22]
^de Bonis, Louis; Koufos, George D. (2004). "Ouranopithecus and dating the splitting of extant hominoids".Comptes Rendus Palevol.3 (4):257–264.doi:10.1016/j.crpv.2004.04.002.
^de Bonis, Louis; et al. (1981). "Dental metric variation in early Hominids comparison betweenAustralopithecus afarensis andOuranopithecus macedoniensis".Comptes Rendus des Séances de l'Académie des Sciences. Serie III Sciences de la Vie.292:263–266.
^Andrews, Martin L. (1984). "The phylogenetic position ofGraeceopithecus freybergi Koenigswald".Courier Forschungsinstitut Senckenberg.69:25–40.
^Koufos, George D.; de Bonis, Louis (2005). "The late Miocene HominoidsOuranopithecus andGraeceopithecus. Implications about their relationships and taxonomy".Annales de Paléontologie.91 (3):227–240.Bibcode:2005AnPal..91..227K.doi:10.1016/j.annpal.2005.05.001.
