Alophe (genus)

Alophe
Temporal occurrence
	early Miocene
	21.9 to 22.2 million years
Locations
	Nakwai , West Turkana , Kenya ;
Systematics
	Monkey (anthropoidea)
	Old World Monkey (Catarrhini)
	Cercopithecoidea
	incertae sedis
	Alophe
Scientific name
	Alophe
	Rasmussen , Friscia , Gutierrez et al., 2019
species
	Alophe metios;

Alophe is an extinct genus of primates that was foundin East Africa during the early Miocene . According to the first description published in 2019, fossils discoveredin Kenya that were assigned to this genus comefrom sedimentary layers that are around 22 million years old. The only species of the genusdescribed so far,and at the same time its type, is Alophe metios .

Naming

Alophe is an artificial word . The name of the genus is derived from the Greek word λόφος ( pronounced lóphos in ancient Greek : yoke, in the sense of an elongated recess on the chewing surfaces of the large molars ) and the prefix "a-" (without). The epithet of the type species, Alophe metios , refers to Metis , the first lover of Zeus in Greek mythology . The reason for the choice of the epithet is stated in the first description: "Metis was feared because of her prophecy that she would produce offspring, more powerful than their father."

The fossils were initially assigned to the genus Alophia in March 2019 . After the researchers noticed that this name had already been given to a butterfly in 1893 , they corrected the name to alophe in June 2019 .

Initial description

In the first description, the fragment of a lower jaw with four preserved right molars ( premolar 4 to molar 3) from the site TOP-01 (archive number KNM-NW 49735) was identified as the holotype of the genus and also the type species Alophe metios . Two smaller, left lower jaw fragments with three or two preserved molars (P3-M1, M2-M3) from the TOP-69 and TOP-73 sites were added as paratypes in the first description.

All three finds are kept in the National Museums of Kenya (formerly: Kenya National Museum ), hence the identifier KNM; NW refers to the Nakwai site west of Lake Turkana .

Age and characteristics

An age of 21.9 million years was calculated for the type specimen, and 22.0 and 22.2 million years for the two paratypes. The genus Alophe consequently lived in an era from which only 19 million and 25 million year old fossils of early Old World monkeys had been identified, thus closing a previously existing gap in the fossil record of the primates of East Africa . According to the first description, Alophe was shorter than the somewhat older genus Nsungwepithecus .

A striking feature that distinguishes Alophe from monkeys from younger epochs is the eponymous lack of elongated depressions (the Lophen) on the chewing surfaces of the molars. They lack the younger types of Cercopithecidae characteristic Bilophodontie, that is, Alophe has no front and rear cusps pairs that are connected by a transverse yoke; This special structure of the molars of younger species is considered a key feature of the evolutionary success of the vervet monkey relatives, which has been demonstrable for 19 million years. The tooth structure of Alophe is interpreted as evidence of a specialization in relatively hard food, consisting for example of the seeds of fruits , while younger species ate more of the leaves of the trees and ate a more varied diet.

Web links

Fossil teeth from Kenya solve ancient monkey mystery. On: phys.org from March 11, 2019

Individual evidence

↑ ^a ^b ^c David Tab Rasmussen, Anthony R. Friscia, Mercedes Gutierrez et al .: Primitive Old World monkey from the earliest Miocene of Kenya and the evolution of cercopithecoid bilophodonty. In: PNAS . Volume 116, No. 13, 2019, pp. 6051–6056, doi: 10.1073 / pnas.181542311 , access to the full text
^ Correction for Rasmussen et al., Primitive Old World monkey from the earliest Miocene of Kenya and the evolution of cercopithecoid bilophodonty. In: PNAS. Volume 116, No. 24, 2019, p. 12109, doi: 10.1073 / pnas.1907208116
^ Tooth fossils fill 6-million-year-old gap in primate evolution. On: eurekalert.org from May 14, 2019

annotation

↑ David Tab Rasmussen had already died in August 2014 and was posthumously identified as the first author of the first description in recognition of his academic achievements.

[Erstbeschreibung-1] David Tab Rasmussen, Anthony R. Friscia, Mercedes Gutierrez et al .: Primitive Old World monkey from the earliest Miocene of Kenya and the evolution of cercopithecoid bilophodonty. In: PNAS . Volume 116, No. 13, 2019, pp. 6051–6056, doi: 10.1073 / pnas.181542311 , access to the full text

[2] Correction for Rasmussen et al., Primitive Old World monkey from the earliest Miocene of Kenya and the evolution of cercopithecoid bilophodonty. In: PNAS. Volume 116, No. 24, 2019, p. 12109, doi: 10.1073 / pnas.1907208116

[4] Tooth fossils fill 6-million-year-old gap in primate evolution. On: eurekalert.org from May 14, 2019

[3] David Tab Rasmussen had already died in August 2014 and was posthumously identified as the first author of the first description in recognition of his academic achievements.