Chororapithecus

Chororapithecus
Temporal occurrence
	Miocene
	approx. 8.0 million years
Locations
	East Africa ( Afar Triangle );
Systematics
	Monkey (anthropoidea)
	Old World Monkey (Catarrhini)
	Human (Hominoidea)
	Apes (Hominidae)
	Chororapithecus
Scientific name
	Chororapithecus
	Suwa , Kono , Katoh , Asfaw & Beyene , 2007
species
	Chororapithecus abyssinicus;

Chororapithecus is an extinct genus of ape from the Miocene whose fossils between 2005 and 2007 in the area of the African Great grave breach in the Afar region in Ethiopia have been excavated. Chororapithecus was described by its discoverers as "a convincing candidate for membership in the taxon of modern gorillas ", that is, as the oldest known ancestor of the gorillas.

Naming

Chororapithecus is a made-up word . The name of the genus is derived from the Chorora formation from which the fossil was recovered, as well as from the Greek word πίθηκος ( pronounced píthēkos in ancient Greek : "monkey"). The epithet of the only scientifically described species so far , Chororapithecus abyssinicus , refers to Abyssinia , the former country name of Ethiopia. The name of the species Chororapithecus abyssinicus accordingly means "Ethiopian [Abyssinian] Chorora monkey".

Initial description

The holotype of the genus and at the same time the type species Chororapithecus abyssinicus is a right upper molar (M2) with the inventory designation CHO-BT 4, which was scientifically described for the first time in August 2007 in the journal Nature . In addition, in the first description of the new genus and species, a canine and another seven molars were used, including two fragments. These teeth have a size comparable to that of the modern western gorilla ( Gorilla gorilla ) and other features, especially of the chewing surfaces , which can be interpreted as being related to the gorillas. The teeth come from at least three, but possibly also from six or more individuals.

The first descriptors of the Japanese-Ethiopian research group describe as less likely, but not completely excluded, that Chororapithecus went through an independent parallel development to the gorillas or that it is a side branch in the tribal history of these recent species.

Relationship and dating

Based on the dental findings, the genus was assigned to the superfamily of the human (Hominoidea). The relatively thick enamel layer of the teeth found is interpreted as a sign of a pronounced herbivorous way of life. According to the first description, this fits in with other fossil finds in the Chorora strata , in which numerous early relatives of our horses ( Hipparion species) were found, whose teeth also indicate a hard, silica- containing food, as it is today, for example, in loose wooded savannahs .

Until these discoveries, the separation of the lineages of gorillas and humans based on estimates of the frequency of mutations (“ molecular clock ”) had been dated to around eight million years ago. From the find circumstances of Chororapithecus it was deduced in 2007 that this separation had taken place considerably earlier; First describer Gen Suwo from the University of Tokyo reported in Nature that the separation took place at least 10 to 11 million years ago. This dating was based on studies from the 1970s on the age of the Chorora formation. In 2016, however, a correction of the age of the Chorora Formation was published - also in Nature - according to which its age is around 9 to 7 million years ago and the Chororapithecus fossils are around 8 million years old.

Primate genera of similar geological age are Dryopithecus , Nakalipithecus , Oreopithecus and Pliopithecus .

Web links

Entry Chororapithecus in the Paleobiology Database

Individual evidence

↑ Gen Suwa, Reiko T. Kono, Shigehiro Katoh, Berhane Asfaw , Yonas Beyene: A new species of great ape from the late Miocene epoch in Ethiopia. In: Nature . Volume 448, 2007, pp. 921-924, doi: 10.1038 / nature06113 .
↑ The name of this geological formation is derived from the village of Chorora , which is about eight kilometers south of the site known as Beticha locality .
^ New Scientist . Volume 195, August 25, 2007, p. 12.
↑ literally: "greater than 10 to 11 million years ago"; Quoted in: Rex Dalton: Oldest gorilla ages our joint ancestor. In: Nature. Volume 448, 2007, pp. 844-845, doi: 10.1038 / 448844a
↑ Shigehiro Katoh et al .: New geological and palaeontological age constraint for the gorilla – human lineage split. In: Nature. Volume 530, No. 7589, 2016, pp. 215-218, doi: 10.1038 / nature16510
Fossil analysis pushes back human split from other primates by 2 million years. On: eurekalert.org of February 16, 2016

[1] Gen Suwa, Reiko T. Kono, Shigehiro Katoh, Berhane Asfaw , Yonas Beyene: A new species of great ape from the late Miocene epoch in Ethiopia. In: Nature . Volume 448, 2007, pp. 921-924, doi: 10.1038 / nature06113 .

[2] The name of this geological formation is derived from the village of Chorora , which is about eight kilometers south of the site known as Beticha locality .

[3] New Scientist . Volume 195, August 25, 2007, p. 12.

[4] terally: "greater than 10 to 11 million years ago"; Quoted in: Rex Dalton: Oldest gorilla ages our joint ancestor. In: Nature. Volume 448, 2007, pp. 844-845, doi: 10.1038 / 448844a

[5] Shigehiro Katoh et al .: New geological and palaeontological age constraint for the gorilla – human lineage split. In: Nature. Volume 530, No. 7589, 2016, pp. 215-218, doi: 10.1038 / nature16510
Fossil analysis pushes back human split from other primates by 2 million years. On: eurekalert.org of February 16, 2016