Algeripithecus

Algeripithecus
Temporal range: Early to Middle Eocene
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Strepsirrhini
Infraorder: incertae sedis
Family: †Azibiidae
Genus: †Algeripithecus
Godinot & Mahboubi, 1992
Species: †A. minutus
Binomial name
Algeripithecus minutus
Godinot & Mahboubi, 1992

Algeripithecus is an extinct genus of early fossil primate, weighing approximately 65 to 85 grams (2.3 to 3.0 oz). Fossils have been found in Algeria dating from 50 to 46 million years ago.

It was once commonly thought to be one of the oldest simian primates (a group that includes monkeys and apes), and was crucial to the hypothesis that simians originated in Africa. Research on more complete specimens suggest it was instead a strepsirrhine primate, more closely related to living lemurs and lorisoids. However, this is still disputed.

Discovery

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 (M2).[1]

Evolutionary history and taxonomy

First described in the journal Nature by Marc Godinot and Mohamed Mahboubi in 1992,[1] 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.[2] Based on the discovery of additional fossil teeth and a maxilla (upper jaw) between 2003 and 2009, Tabuce et al. reconstructed Algeripithecus as an azibiid,[3] a group thought to be a type of stem lemuriform, or strepsirrhine primate.[4] 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 anterior dentition of azibiids is unknown, they may have possessed a toothcomb, indicating an ancient stem lineage of lemuriform primates in Africa,[5] possibly descended from an early Asian branch of adapiforms[6] such as a primitive branch of cercamoniines predating Donrussellia (one of the oldest European adapiforms).[7] As a result, the African origins of crown strepsirhines (including lemurs and lorisoids) is well supported, whereas the African origins of simians has been placed in doubt, possibly giving favor to an Asian origins hypothesis.[4] 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.[8] In 2011, Marivaux et al. published an interpretation of recently discovered talus bones[lower-alpha 1] 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.[10]

Godinot also cautiously suggested that Dralestes may be a synonym of Algeripithecus based on a blade-like premolar.[8] Alternatively, the second upper molar (M2) of Dralestes hammadaensis have been reinterpreted by Tabuce et al. as being the upper fourth premoloar (P4) of Azibius, and therefore considered Dralestes to be a synonym of Azibius. Specimens of Dralestes are now recognized as being either Azibius and Algeripithecus.[11]

Anatomy and physiology

Like all azibiids, Algeripithecus was a small-bodied primate.[12] Initially thought to weigh 150 to 300 g (5.3 to 10.6 oz),[1] Algeripithecus minutus is now estimated[lower-alpha 2] to have weighed between 65 and 85 g (2.3 and 3.0 oz), nearly half the weight of the only other known azibiid, Azibius trerki.[13] It was comparable in size to a hairy-eared dwarf lemur (Allocebus trichotis) or a brown mouse lemur (Microcebus rufus).[12]

Notes

  1. ↑ Talus bones are commonly used to taxonomically differentiate simians from "prosimian" primates in the fossil record.[9]
  2. ↑ Size estimates were calculated using regressions of the area of the first molar compared to living primates.[13]

References

  1. 1 2 3 Godinot & Mahboubi 1992, p. 324.
  2. ↑ Tabuce et al. 2009, pp. 4087–4088.
  3. ↑ Tabuce et al. 2009, p. 4089.
  4. 1 2 Tabuce et al. 2009, p. 4087.
  5. ↑ Tabuce et al. 2009, pp. 4092–4093.
  6. ↑ Godinot 2006, pp. 461–462.
  7. ↑ Godinot 2006, pp. 454–455.
  8. 1 2 Godinot 2010, pp. 322–323.
  9. ↑ Marivaux et al. 2011, p. 451.
  10. ↑ Marivaux et al. 2011, pp. 452–453.
  11. ↑ Tabuce et al. 2009, pp. 4088–4089.
  12. 1 2 Marivaux et al. 2011, p. 453.
  13. 1 2 Tabuce et al. 2009, p. 4088.

Literature cited

  • Godinot, M.; Mahboubi, M. (1992). "Earliest known simian primate found in Algeria". Nature 357 (6376): 324–326. doi:10.1038/357324a0. PMID 1589034. 
  • Godinot, M. (2006). "Lemuriform origins as viewed from the fossil record". Folia Primatologica 77 (6): 446–464. doi:10.1159/000095391. PMID 17053330. 
  • Godinot, M. (2010). "Chapter 19: Paleogene Prosimians". In Werdelin, L.; Sanders, W.J. Cenozoic Mammals of Africa. University of California Press. ISBN 978-0-520-25721-4. 
  • Marivaux, L.; Tabuce, R.; Lebrun, R.; Ravel, A.; Adaci, M.; Mahboubi, M.H.; Bensalah, M. (2011). "Talar morphology of azibiids, strepsirhine-related primates from the Eocene of Algeria: Phylogenetic affinities and locomotor adaptation". Journal of Human Evolution 61 (4): 447–457. doi:10.1016/j.jhevol.2011.05.013. PMID 21752425. 
  • Tabuce, R.; Marivaux, L.; Lebrun, R.; Adaci, M.; Bensalah, M.; Fabre, P. -H.; Fara, E.; Gomes Rodrigues, H.; Hautier, L.; Jaeger, J. -J.; Lazzari, V.; Mebrouk, F.; Peigne, S.; Sudre, J.; Tafforeau, P.; Valentin, X.; Mahboubi, M. (2009). "Anthropoid versus strepsirhine status of the African Eocene primates Algeripithecus and Azibius: Craniodental evidence" (PDF). Proceedings of the Royal Society B: Biological Sciences 276 (1676): 4087–4094. doi:10.1098/rspb.2009.1339. Lay summary – Science Daily (15 September 2009). 


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