Rangwapithecus

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Rangwapithecus
The fossil KNM-SO 700, the holotype of Rangwapithecus gordoni

The fossil KNM-SO 700,
the holotype of Rangwapithecus gordoni

Temporal occurrence
Early Miocene
19 million years
Locations
Systematics
Monkey (anthropoidea)
Old World Monkey (Catarrhini)
Apes (Hominidae)
Dryopithecini
Rangwapithecus
Scientific name
Rangwapithecus
( Andrews , 1974)
species
  • Rangwapithecus gordoni

Rangwapithecus is an extinct genus of primates that was foundin East Africa around 19 million years agoduring the early Miocene . The first description of the genus and the type species Rangwapithecus gordoni was published in 1974 by Peter Andrews in the journal Nature . At that time,however, Andrews referred to the fossils as belonging to the newly introduced species Dryopithecus gordoni and to the also newly described subgenus Rangwapithecus ; later this was raised to a genus.

Naming

Rangwapithecus is an artificial word . The name of the genus refers to the site near Rangwa Hill (Rangwa Mountain), a rounded elevation of approximately 300 meters above the surrounding area, not far from the northeastern shore of Lake Victoria in Kenya. The second half of the generic name is derived from the Greek word πίθηκος ( pronounced píthēkos in ancient Greek : "monkey"). The epithet of the type species Rangwapithecus gordoni refers to the doctor FJ Gordon from the Kenyan city of Koru ( Kisumu County ), who recovered numerous early monkey fossils. Rangwapithecus gordoni therefore means "Gordon's monkey of Rangwa".

The National Museums of Kenya (formerly: Kenya National Museum, KNM) are the custody of the finds .

Initial description

The holotype of the genus and type species Rangwapithecus gordoni is the well-preserved upper jaw KNM-SO 700, in which, with the exception of the incisors, all the rest of the dentition is still present. Together with the holotype, 79 other fossils were added as paratypes to the first description, including numerous teeth (including incisors), fragments of the lower jaws, as well as further upper jaw fragments and remains of palate bones. The size of the teeth of Rangwapithecus gordoni was reconstructed as an intermediate between Siamangs and bonobos living today and similar in size to the teeth of Dryopithecus africanus .

Together with Rangwapithecus gordoni , a significantly smaller sister species was first described in 1974, called Rangwapithecus vancouveringi . The holotype KNM-RU 2058 - a partially preserved, dentate upper jaw from the Rusinga Island site - was added seven other fossils as paratypes that had been recovered from neighboring sites. These were molars from the upper jaw and fragments of upper jaw bones. The size of the teeth was stated to be comparable to that of the Siamangs living today. Deviations in the blueprint of the teeth between the two species were found in the first description of both species only in the case of molar M1.

In 1974 Peter Andrews named these two newly named species Dryopithecus gordoni and Dryopithecus vancouveringi in their first description and introduced the name Rangwapithecus as a subgenus of the genus Dryopithecus . He wanted to make it so clear that both species differ considerably from the other three species of the genus Dryopithecus recognized at the time ; Dryopithecus africanus , Dryopithecus major and Dryopithecus nyanzae were combined in the subgenus Proconsul at the time , today they are mostly assigned to the genus Proconsul . After had been discovered in Kenya additional fossils from the early Miocene, argued Terry Harrison in 1986 that Rangwapithecus gordoni so materially from those to Rangwapithecus vancouveringi distinction made discoveries that for Rangwapithecus vancouveringi own generic expedient was. Following the international rules for zoological nomenclature , the epithet vancouveringi , which refers to the New York anthropologist John Van Couvering and his wife Judith Van Couvering , was retained in this renaming and assignment to the newly established genus Nyanzapithecus ; John Van Couvering discovered the type specimen KNM-RU 2058 in 1968. This renaming had the consequence that since then Rangwapithecus gordoni is the only scientifically described species of the genus Rangwapithecus .

More finds

The peculiarities of the tooth morphology of Rangwapithecus gordoni in comparison with other species of the early Miocene have been repeatedly confirmed on the basis of further fossil finds ; Among other things, in 2013 the first lower jaw of the species described as “definitely female” was described. Also in 2013, in connection with a further description of the find, it was confirmed that Rangwapithecus gordoni differs significantly from the species assigned to Proconsul , but has similarities with Nyanzapithecus and Turkanapithecus . It was also emphasized that the fossils of Rangwapithecus gordoni come exclusively from the Songhor site, from which it was deduced that this place differed ecologically from neighboring fossil sites during the life of the species.

Based on the nature of the teeth, it was argued that the individuals of the species weighed around 15 kilograms and that they mainly fed on leaves in tropical rainforests. The relationship of the species to older or younger species is unclear.

literature

Web links

Individual evidence

  1. ^ Songhor: Geographical Location and Historical Background.
  2. ^ A b Peter Andrews : New species of Dryopithecus from Kenya. In: Nature . Volume 249, 1974, pp. 188-190, doi: 10.1038 / 249188a0
  3. ↑ Terry Harrison : New Fossil Anthropoids From the Middle Miocene of East Africa and Their Bearing on the Origin of the Oreopithecidae. In: American Journal of Physical Anthropology. Volume 71, No. 3, 1986, pp. 265–284, doi: 10.1002 / ajpa.1330710303 , full text (PDF)
  4. ↑ Susanne Cote, Nasser Malit and Isaiah Nengo: Additional mandibles of Rangwapithecus gordoni, an early Miocene catarrhine from the Tinderet localities of Western Kenya. In: American Journal of Physical Anthropology. Volume 153, 2014, pp. 341-352, doi: 10.1002 / ajpa.22433
  5. ↑ Andrew Hill, Isaiah Odhiambo Nengo and James B. Rossie: A Rangwapithecus gordoni mandible from the early Miocene site of Songhor, Kenya. In: Journal of Human Evolution. Volume 65, No. 5, 2013, pp. 490-500, doi: 10.1016 / j.jhevol.2013.02.014
  6. ↑ John G. Fleagle : Primate Adaptation and Evolution. Academic Press, 2nd Edition, San Diego 1999, p. 462.