''Ganlea'' is a fossil

primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

from central

Myanmar Myanmar, officially the Republic of the Union of Myanmar; and also referred to as Burma (the official English name until 1989), is a country in northwest Southeast Asia. It is the largest country by area in Mainland Southeast Asia and has ...

, formerly known as Burma. Its age is about 38 million years, living during the late

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

epoch. ''Ganlea'' belongs to the group of

anthropoids The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called monkeys and apes. More precisely, they consist of the parvorders Platyrrhini (New World monkeys) and Catar ...

(i. e. humans, apes and monkeys), and is in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Amphipithecidae The Amphipithecidae were simian primates that lived in Late Eocene and Rupelian, Early Oligocene. Fossils have been found in Myanmar, Thailand, and Pakistan. The limited fossil evidence is consistent with, but not exclusive to, arboreal quadruped ...

. It is older than any other known anthropoid from

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, and is the second oldest known from

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. Its remains consist of teeth and jawbones belonging to 10 to 15 individuals found near the city of

Bagan Bagan ( ; ; formerly Pagan) is an ancient city and a UNESCO World Heritage Site in the Mandalay Region of Myanmar. From the 9th to 13th centuries, the city was the capital of the Pagan Kingdom, the first kingdom that unified the regions that w ...

in the central part of the country. The teeth of ''Ganlea'' have many diagnostic features that help to show its relations with other anthropoids. It is thought to be closely related to the genera '' Myanmarpithecus'', '' Pondaungia'' and '' Siamopithecus'', both found from the same area as ''Ganlea''. In all of these genera, the

canine tooth In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, eye teeth, vampire teeth, or fangs, are the relatively long, pointed teeth. In the context of the upper jaw, they are also known as '' fangs''. They can appear more f ...

is enlarged and compressed anteroposteriorly, making it quite wide. A great deal of tooth wear has been observed in ''Ganlea'', which has been viewed as an adaptation for consuming nuts and seeds, similar to the modern Saki monkey. The large size of the canine tooth in ''Ganlea'' gives it the specific name "''megacanina''". Phylogenetic analyses conducted upon the description of ''Ganlea'' suggest that the amphipithecids are closely related to

New World monkey New World monkeys are the five families of primates that are found in the tropical regions of Mexico, Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboi ...

s (Platyrrhini) and the extinct propliopithecids. This places it firmly within Haplorrhini. ''

Darwinius ''Darwinius'' is a genus within the infraorder Adapiformes, a group of basal strepsirrhine primates from the middle Eocene epoch. Its only known species, ''Darwinius masillae'', lived approximately 47 million years ago (Lutetian stage) based ...

'', a primate recently described and quickly claimed a

transitional fossil A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross ...

of great importance to human ancestry, is a member of the

Adapiformes Adapiformes is a group of early primates. Adapiforms radiated throughout much of the northern continental mass (now Europe, Asia and North America), reaching as far south as northern Africa and tropical Asia. They existed from the Eocene to the ...

, which has recently been viewed as a transitional group between

Strepsirrhini Strepsirrhini or Strepsirhini (; ) is a Order (biology), suborder of primates that includes the Lemuriformes, lemuriform primates, which consist of the lemurs of Fauna of Madagascar, Madagascar, galagos ("bushbabies") and pottos from Fauna of A ...

and Haplorrhini. This means that ''Ganlea'' is more closely related to modern monkeys and apes than ''Darwinius'' is. Because of its age, ''Ganlea'' has been called a missing link that places the origin of all anthropoids (including

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

s) in Asia rather than Africa as was previously thought. However, doubts have been raised towards the claim that it is the ancestor of all other anthropoids. Other extinct primates such as ''

Eosimias ''Eosimias'' is a genus of early primates, first discovered and identified in 1999 from fossils collected in the Shanghuang fissure-fillings of Liyang, the southern city of Jiangsu Province, China. It is a part of the family Eosimiidae, and inclu ...

'' seem to be more basal members than ''Ganlea''.The description of ''Eosimias'' by

Beard A beard is the hair that grows on the jaw, chin, upper lip, lower lip, cheeks, and neck of humans and some non-human animals. In humans, beards are most commonly seen on pubescent or adult males, though women have been observed with beards ...

''et al.'' in 1994 can be seen as the beginning of the recent debate on the Asian ancestry of anthropoids Because ''Ganlea'' is a true anthropoid, it has been seen as more likely to be a direct ancestor of monkeys and apes (and thus humans) than ''Darwinius'' would. However, the phylogenetic analysis that was conducted on it suggests that it is too derived to have been an ancestral anthropoid, and its close relation with New World monkeys seems to imply that it was not a human ancestor, as apes are believed to have evolved from

Old World monkey Old World monkeys are primates in the family Cercopithecidae (). Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons (genus '' Papio''), red colobus (genus '' Piliocolob ...

References

External links

A new primate from the Eocene Pondaung Formation of Myanmar and the monophyly of Burmese amphipithecids, by K. Christopher Beard at al., Proceedings of the Royal Society B (Biological Sciences) on July 1, 2009

Eurekalert article, by Leigh Kish
{{Taxonbar, from=Q144030 Eocene primates Prehistoric monkeys Fossil taxa described in 2009 Monotypic prehistoric primate genera Eocene mammals of Asia Fossils of Myanmar

See also

References

External links