Ardipithecus kadabba

Ardipithecus kadabba
Ardipithecus kadabba
Temporal occurrence
Upper Miocene
5.8 to 5.2 million years
Locations
Ethiopia
Systematics
Human (Hominoidea) Apes (Hominidae) Homininae Hominini Ardipithecus Ardipithecus kadabba
Scientific name
Ardipithecus kadabba
Yohannes Haile-Selassie , 2001

Ardipithecus Kadabba is an extinct type of ape from Africa whose skeletal remains were first dated at 5.8 to 5.2 million years ago, and later on from 5.77 to 5.54 million years. The first description , according to the available fossils the common ancestor of chimpanzees and humans suggests their lineages to molecular biology parted estimated prior to 6.5 to 5.5 million years ago.

Naming

Ardipithecus is an artificial word . The name of the genus is partly derived from the Afar language (from "ardi" = soil), partly from Greek (from "πίθηκος", pronounced "píthēkos" = monkey in ancient Greek). The epithet kadabba comes from the Afar language and denotes the progenitor of a family. Ardipithecus kadabba therefore means "ancestor of the ground monkeys".

Initial description

The holotype of Ardipithecus kadabba is a right lower jaw fragment with a preserved molar (M3) and five tooth or root fragments with the inventory number ALA-VP-2/10. The first description from 2001 is based on other bone finds that have been excavated since 1992 at a total of five sites in the Afar Depression , Ethiopia , and come from ten other individuals. In the first description by Yohannes Haile-Selassie , however , Ardipithecus kadabba was still identified as a subspecies of Ardipithecus ramidus and called Ardipithecus ramidus kadabba . It was not until 2004 that this name was revised in a joint publication by Haile-Selassie and the discoverer of Ardipithecus ramidus , Tim White .

features

This correction of the initial assignment of the fossil finds as a subspecies was justified by the fact that Ardipithecus kadabba has more "primitive" features than the fossils assigned to the species Ardipithecus ramidus . Ardipithecus kadabba thereby show at the same time a greater similarity with the genera Sahelanthropus and Orrorin . These statements were based on other bone finds that came to light in November 2002 and were dated to an age of 5.8 to 5.6 million years.

At the same time, it was emphasized that no evidence of so-called honing was found, that is to say of grinding marks on the teeth, as they are known from all older finds. They arise when the canine teeth rub against each other when biting, thus constantly sharpening their tips. In order to be able to carry out this “honing”, the dentition has a gap next to each canine ( diastema ) into which the canine of the antagonistic jaw fits. The loss of this feature is used as an argument for assigning the finds to that line of development of the great apes that later led to the australopithecines and finally to the genus Homo .

Finally, it was noted in the same publication that Ardipithecus , Sahelanthropus and Orrorin belong to the same group of forms and - after finding more finds - could possibly be assigned to a single genus.

In 2008, Bernard Wood and Nicholas Lonerga pointed out that the features of the dentition of Ardipithecus kadabba, which differ significantly from other species of hominini, make its assignment to the hominini appear less well-founded than is the case with Ardipithecus ramidus .

Habitat

According to the first description, accompanying paleontological finds suggest that Ardipithecus kadabba lived in a habitat that consisted of forests, tree-lined savannas and open water, as was also described for Sahelanthropus .

See also

• Ardi

Individual evidence

1. ^ Website of Yohannes Haile-Selassie at the Cleveland Museum of Natural History.
2. ^ Yohannes Haile-Selassie : Late Miocene hominids from the Middle Awash, Ethiopia. In: Nature . Volume 412, 2001, pp. 178-181, doi: 10.1038 / 35084063
3. ↑ Yohannes Haile-Selassie, Gen Suwa, Tim White: Late Miocene Teeth from Middle Awash, Ethopia, and early hominid dental evolution. In: Science . Volume 303, 2004, pp. 1503-1505, doi: 10.1126 / science.1092978
4. ↑ Bernard Wood , Nicholas Lonergan: The hominin fossil record: taxa, grades and clades. In: Journal of Anatomy . Volume 212, No. 4, 2008, p. 356 f., Doi: 10.1111 / j.1469-7580.2008.00871.x , full text (PDF; 292 kB) ( Memento from October 29, 2013 in the Internet Archive )
5. ↑ Giday Wolde-Gabriel et al .: Geology and palaeontology of the Late Miocene Middle Awash valley, Afar rift, Ethiopia. In: Nature. Volume 412, 2001, pp. 175-178, doi: 10.1038 / 35084058