Panamace bus

Panamace bus
Temporal occurrence
	Early Miocene
	20.9 million years
Locations
	Lirio Norte Local Fauna Locality, ; Panama Canal Basin, Panama ;
Systematics
	Primates (Primates)
	Monkey (anthropoidea)
	New World Monkey (Platyrrhini)
	Capuchins (Cebidae)
	Panamace bus
Scientific name
	Panamace bus
	Bloch et al., 2016
species
	Panamacebus transitus;

Panamacebus is an extinct genus of primates that was foundin Central America during the early Miocene . Fossils discoveredin Panama belonging to this genus were dated to 20.9 million years ago. The only species of the genusdescribed so faris Panamacebus transitus , probably a close relative of the capuchin monkeys living today. The genus and species were first scientifically described in 2016.

Naming

Panamacebus is an artificial word . The name of the genus refers on the one hand to the place where it was found in Panama and on the other hand to the primate genus Cebus , which gives the primate family of the Capuchin-like (Cebidae) and to which the fossil genus Panamacebus was assigned. Panamacebus therefore means "Capuchins from Panama". The epithet of the only scientifically described species so far, Panamacebus transitus , means in Latin "place of passage", "passage", "crossing" and refers to the assumed early expansion of the Capuchin species from South America to North America .

Initial description

As a holotype of the genus and at the same time the type species Panamacebus transitus , a left, upper first molar (M ¹ , archive number UF 280128) was identified in the first description , to which six further teeth - presumably from the same individual - were placed as paratypes : a left, upper second molar (M ² ), a partially preserved left, lower first incisor (I ₁ ), a right, lower second incisor (I ₂ ), a right lower canine (C ₁ ) and two left lower premolars (P ₂ and ( P ₄ ) These seven individually found teeth are the only known evidence of Panamacebus .

The teeth were discovered by postdoc Aaron R. Wood on the eastern slope of the Panama Canal at the Lirio Norte site , in the upper area of the Las Cascadas formation . The site had been cleared of vegetation due to the widening of the Panama Canal. Due to deposits from a volcanic eruption, an age of 20.93 ± 0.17 million years could be calculated for the teeth using the uranium-lead dating of magmatic zirconia . The weight of a specimen of Panamacebus transitus was reconstructed from the size of the teeth ; this species was therefore a medium-sized primate with a body weight of approx. 2.7 kilograms. According to the first description, the characteristics of the teeth distinguish it from those of the Miocene capuchin-like genus Acrecebus , but also from the genus Neosaimiri , the close fossil relatives of the squirrel monkey ( Saimiri ).

Meaning of the finds

Panamacebus is considered to be the earliest evidence of the spread of the New World monkeys from South America to North America, since the geological and geographical location already belongs to North America. Panama was the extreme southern tip of North America 21 million years ago; At that time, South America was still separated from the north by a narrow strait , as the Isthmus of Panama only closed around three million years ago. The researchers therefore assume that the monkeys crossed the strait on "rafts" made of plant material or driftwood ; Until the genus was discovered, the oldest evidence of this form of spread was 8.5 to 9 million years old.

literature

Jonathan I. Bloch, Aaron R. Wood et al .: First fossils of a platyrrhine monkey from Panama provide evidence for mammalian dispersal across the Central American Seaway in the Early Miocene. In: Proceedings of the 4th International Paleontological Congress. The history of life: a view from the Southern Hemisphere. Argentina, Mendoza 2014, p. 374, full text

Web links

Monkey ancestors rafted across the sea to North America. On: sciencemag.org from April 20, 2016
21-million-year-old fossil is North America's first monkey. On: newscientist.com from April 20, 2016
Illustration and detailed description of the holotype UF 280128

Individual evidence

↑ ^a ^b ^c ^d Jonathan I. Bloch et al .: First North American fossil monkey and early Miocene tropical biotic interchange. In: Nature . Volume 533, 2016, pp. 243-246, doi: 10.1038 / nature17415
^ Paleontologists find North America's oldest monkey fossil along Panama Canal. On: eurekalert.org of April 21, 2016

[Bloch2016-1] Jonathan I. Bloch et al .: First North American fossil monkey and early Miocene tropical biotic interchange. In: Nature . Volume 533, 2016, pp. 243-246, doi: 10.1038 / nature17415

[2] Paleontologists find North America's oldest monkey fossil along Panama Canal. On: eurekalert.org of April 21, 2016