Program No.18-036

Morphological Study on the fossil hominoids in the Late Cenozoic of Southeast Asia.

Yutaka Kunimatsu

11th Febriary,2007 - 25th Febriary,2007

Today, orangutans and gibbons live in Southeast Asia. Their evolutionary history is not well known at present. Some orangutan and gibbon fossils have been reported from Pleistocene fossil sites, but fossil hominoids of older ages are quite rare in this region. I have been searching for hominoid fossils in Southeast Asia, in collaboration with geologists and paleontologists. In February of 2007, I carried out a paleontological fieldwork in Thailand and examined Pleistocene orangutan and gibbon fossils in the Archaeological Institute of Vietnam. In Thailand, I visited the Chiang Muan lignite mine, and looked for fossils at outcrops of Middle to Late Miocene sediments in the mine. Some fossils of orangutan-sized hominoids have been discovered from the Chiang Muan mine. In this fieldwork, additional specimens of fossil mammals, which are contemporaneous to the hominoids, were collected. Moreover, I visited Mae Long in the Li Basin, south of Chiang Mai, and sieved several large bags of clay, which seemed to contain fossils. As a result, fossils of some small animals like rodents were picked up, confirming that the clay sediments at Mae Long is still fossiliferous. In Vietnam, I visited the Archaeological Institute in Hanoi. I examined the specimens of fossil orangutans and gibbons discovered from several limestone cave sites. In addition, I checked the animal remains from the Holocene Han Cho site, together with Dr. Junmei Sawada of St. Marianna Medical College, and picked up primate specimens. I also discuss the research of primate fossils in Vietnam, with Dr. Vu The Long and other members of the Archaeological Institute.

Chiang Muan coal field in Northern Thailand.
Middle to Late Miocene fossils, including large hominoids, have been discovered.

Archaeological Institute of Vietnam in Hanoi.

HOPE Project<>