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Earliest Primate of the World |
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Teeth and bits of jaw from a tiny, squirrel-sized animal that lived 40
million years ago in what is now Myanmar (Burma) suggest primates
originated in Asia, not Africa as was believed, researchers said. A team
of researchers from France, Japan, and Myanmar say the little animal,
which they have named Bahinia pondaungensis, was probably the ancestor
of modern apes, monkeys and humans. Jean-Jacques Jaeger of the
Universite Montpellier-II in France and colleagues found the fossils in
a layer of red clay, along with a complete lower jaw from a more
advanced primate called Amphipithecus. Writing in the journal Science, they say their findings may help decide where the earliest anthropoids -- the advanced primates that include humans, monkeys and apes -- came from. Origin of Mankind? The Bahinia find is important because it tells us that there was a complex community of primates living in Asia, a tremendous anthropoid radiation much earlier than anyone thought. We didn't have that kind of information about Asia before, only Africa. Now we may have to change our whole story about anthropoid origins and evolution.'' said the researchers. The fossilized remains of many early anthropoids have been found in Africa, most from a single rich site in Egypt. Many scientists thus believed that Africa, already believed by many scientists to be the cradle of humanity, also gave rise to earlier ancestors. But a number of fossils have recently been found in Thailand, China, and Myanmar. They are between 49 million and 33 million years old and include some of the most primitive-looking anthropoids ever found. Anthropoids Could be from Asia Jaeger's team found that Bahinia's teeth strongly resemble the most primitive of all, a creature called Eosimias that was found in China. If Eosimias was indeed an anthropoid, it is so old and primitive that it strongly suggests anthropoids originated in Asia. If it is not, the case is still open on the origins of humanity's ancestors. Bahinia is important because it is a much more complete fossil than Eosimias. With the additional fossil material, we were able to look at more dental characters, and these extra characters in the Bahinia fossil helped us to confirm that Eosimias is definitely an anthropoid. Bahinia and Eosimias are the most primitive anthropoids ever uncovered, and both have been found in Asia and not in Africa. Jaeger and colleagues said this strongly suggests anthropoids evolved in Asia and migrated to Africa. Primates include some small and primitive animals, including bush babies and lemurs. But Bahinia is small by any standards, weighing only about 14 ounces -- the size of the smallest South American monkeys. It would have lived in trees and probably eaten insects, judging from the shape of its teeth. The pondaung mammalian fauna: new interpretations of its affinities, relative age, and ecology HOLROYD, P. A and Russell L. Ciochon, Univ. of Iowa November 1995, Pittsburgh, Pennsylvania [Abstracts for the Annual Meeting of the Society of Vertebrate Paleontology] The late middle Eocene mammalian fauna from the Pondaung sandstones of the Chindwin-Irrawaddy Basin, Burma (also called Myanmar) is best known for its diverse anthracotheriid artiodactyl fauna and its enigmatic anthropoid-like primates. Historically, the fauna has been regarded as penecontemporaneous with and related to those from the Bose Basin, Guangxi Province, China, and Krabi, Thailand. Continuing research on the Pondaung fauna and its depositional setting has provided new insights on its relationships to these other Asian faunas. New familial affinities have been identified for rarer elements in the fauna: Pondaungia has been recognized as an adapid primate; a helohyid has emerged from the previously-described artiodactyl fauna; and Indomeryx is recognized as a primitive gelocid artiodactyl. An additional new species of anthracothere, close to Anthracokeryx birmanicus, has also been identified. Comparisons with the Bose Basin fauna show that there is neither specific nor generic continuity between the two faunas, and the Pondaung fauna cannot be used to aid in the dating of the Chinese fauna. Comparisons with the Krabi fauna show significant similarity at the generic level in the anthracotheriid faunas with closely-related species of the same genera present. However, there are marked differences in overall faunal composition between the Thai and Burmese sites. These differences are the primarily the absence of amynodontids in the Krabi fauna, the lack of smaller mammals from the Pondaung fauna, and the greater diversity of the Krabi fauna. These differences arise from a combination of taphonomy, differing collecting techniques, possible temporal or latitudinal differences, and distinctly different ecologies as indicated by depositional environments. Due to these differences, it is difficult to assess how much time, if any, separates these faunas based on mammalian biocorrelation. |
