| Altiatlasius | |
|---|---|
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Primates |
| Genus: | †Altiatlasius Sigéet al., 1990 |
| Species: | †A. koulchii |
| Binomial name | |
| †Altiatlasius koulchii Sigéet al., 1990 | |
Altiatlasius is an extinct genus ofmammal, which may have been the oldest knownprimate, dating to the LatePaleocene (c.57 ma) fromMorocco. The only species,Altiatlasius koulchii, was described in 1990.
Its true taxonomic position remains controversial. It has also been suggested that it should be classified as aplesiadapiform (an extinct group of arboreal mammal thought to be ancestral to primates) or that it should be recognized as a euprimate, either as anomomyid (a branch offossil primates thought to be closely related totarsiers), an early tarsiiform, or the oldeststemsimian (monkeys and apes).
Altiatlasius koulchii, potentially the oldest known euprimate,[1] is known only from ten isolated upper and lowermolars and a fragment of amandible.[a][4][5] These fossils date to the LatePaleocene, approximately 57 million years ago,[b] and come from the Jbel Guersif Formation in the Ouarzazate Basin ofMorocco.[4] First described in 1990 by Sigéet al.,Altiatlasius was originally proposed to be anomomyid, possibly close to the split withsimians (monkeys and apes). It has also been classified in the familyToliapinidae, a type ofplesiadapiform found in Europe.[3][7] Other classifications assume they arestem euprimates,eosimiid-like simians,[2] or an early tarsiiform.[7] Many authorities considerAltiatlasius to be the oldest stem simian.[2][3] Godinot (1994) and Bajpaiet al. (2008) both support the view that it is an earlyanthropoid (simian).[8]
Together with the Early to MiddleEocene fossil primateAlgeripithecus (originally thought to be the oldestcrown simian) fromAlgeria,Altiatlasius helped strengthen the argument for an African origin of simian primates.[9] However, when additional fossil remains ofAlgeripithecus were found, it was shown to be astrepsirrhine primate instead of ahaplorhine, placing it with theazibiids,[10] a group thought to be most closely related tolemuriforms (livinglemurs andlorisoids).[11] BecauseAlgeripithecus was radically reclassified with the discovery of more fossils, equally fragmentary remains ofAltiatlasius leave itsphylogenetic affinities questionable. Also, the 20 million year gap in the fossil record betweenAltiatlasius and the firstparapithecoids raises questions about the validity of the African origins hypothesis for simians.[2]
