Ardipithecus

Ardipithecus
Temporal range: Late Miocene - Early Pliocene, 5.77–4.4 Ma
Ardipithecus ramidus specimen, nicknamed Ardi
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Hominidae
Subfamily: Homininae
Tribe: Hominini
Subtribe: Hominina
Genus: Ardipithecus
White et al., 1995
Species

Ardipithecus is a genus of an extinct hominine that lived during the Late Miocene and Early Pliocene epochs in the Afar Depression, Ethiopia. Originally described as one of the earliest ancestors of humans after they diverged from the chimpanzees, the relation of this genus to human ancestors and whether it is a hominin is now a matter of debate.[1] Two fossil species are described in the literature: A. ramidus, which lived about 4.4 million years ago[2] during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago (late Miocene).[3] Initial behavioral analysis indicated that Ardipithecus could be very similar to chimpanzees,[1] however more recent analysis based on canine size and lack of canine sexual dimorphism indicates that Ardipithecus was characterised by reduced aggression,[4] and that they more closely resemble bonobos.[5]

Some analyses describe Australopithecus as being sister to Ardipithecus ramidus specifically.[6] This means that Australopithecus is distinctly more closely related to Ardipithecus ramidus than Ardipithecus kadabba. Cladistically, then, Australopithecus (and eventually Homo sapiens) indeed emerged within the Ardipithecus lineage, and this lineage is not literally extinct.

  1. ^ a b Stanford, Craig B. (2012). "Chimpanzees and the Behavior of Ardipithecus ramidus". Annual Review of Anthropology. 41: 139–49. doi:10.1146/annurev-anthro-092611-145724. SSRN 2158257.
  2. ^ Perlman, David (July 12, 2001). "Fossils From Ethiopia May Be Earliest Human Ancestor". National Geographic News. Archived from the original on July 15, 2001. Retrieved March 18, 2017. Another co-author is Tim D. White, a paleoanthropologist at UC-Berkeley who in 1994 discovered a pre-human fossil, named Ardipithecus ramidus, that was then the oldest known, at 4.4 million years.
  3. ^ Cite error: The named reference AndThePaleobiology was invoked but never defined (see the help page).
  4. ^ Wilson, Clare (29 November 2021). "Canine teeth shrank in human ancestors at least 4.5 million years ago". New Scientist. Retrieved 2021-12-01.
  5. ^ Suwa, Gen; Sasaki, Tomohiko; Semaw, Sileshi; Rogers, Michael J.; Simpson, Scott W.; Kunimatsu, Yutaka; Nakatsukasa, Masato; Kono, Reiko T.; Zhang, Yingqi; Beyene, Yonas; Asfaw, Berhane; White, Tim D. (2021-12-07). "Canine sexual dimorphism in Ardipithecus ramidus was nearly human-like". Proceedings of the National Academy of Sciences. 118 (49). Bibcode:2021PNAS..11816630S. doi:10.1073/pnas.2116630118. ISSN 0027-8424. PMC 8670482. PMID 34853174.
  6. ^ Pugh, Kelsey (February 2020). The Phylogenetic Relationships of Middle-Late Miocene Apes: Implications for Early Human Evolution (Thesis).