CENOZOIC ERA
A series of Paleogene – Neogene basins extend from Northern to Southern Thailand. The Krabi Basin in the South, considered to be Late Eocene based on vertebrate fossils, has yielded many fossils, including approximately 6 reptile species: snakes, crocodiles, and turtles, and 27 species of mammals: primates, artiodactyls, perrissodactyls. A thick deposit of shells, predominantly of gastropods, also occurs. In addition, plant macrofossils and pollen were collectedfrom the basin.
The basins in Northern Thailand include Mae Moh, Mae Tip, Pong, Chiang Muan, Lampang, Li, and Mae Sod basins. About 43 mammalian species, including a primate, carnivores, artiodactyls, bats, tree shrews, rodents, and proboscideans, have been recovered . Reptiles and mollusks also occur as fossils. Plant macrofossils, especially angiosperm leaves and conifer twigs and needles, as well pollen, have been found in some of these basins. Although the animal remains are mostly Miocene, the plant fossils range from Middle Miocene to Early Miocene or Oligocene.
In the Northeast, vertebrate fossils consist of numerous mammalian species, including about 9 proboscidean species, a primate, carnivores, hoofed mammals, and reptiles, such as crocodiles, gavials, soft-shelled turtles, and turtles. Many specimens were found in the Mun River floodplains in Nakhon Ratchasima Province.
Petrified wood from Miocene – Pleistocene deposits has been found abundantly throughout the Northeast. The wood shows a high diversity, particularly of the families Leguminosae, Dipterocarpaceae, and Combretaceae. Leaves, wood, fruits, seeds, resin, and pollen have also been found, especially in Pleistocene deposits. A wide variety of vertebrates have been found in caves throughout Thailand, including pandas, hyenas, orangutans, and rodents, mostly from the Pleistocene and Holocene. Numerous Holocene fossils, especially mollusks, have been recovered from Thai marine deposits.