Charcoalified fragments of wood scattered in what appear to be compressed ashes from a fire have been found in Lampang Basin, Lampang district, Northern Thailand, an inland terrestrial basin of Tertiary age, possibly Miocene. Approximately four species of conifers are represented by the charcoalified wood fragments; annual rings are present in all the wood. One fragment appears to be compression wood, with tracheids showing extensive splitting of the secondary cell walls. A traumatic resin canal is also present. A few axial parenchyma cells were observed, and the rays are uniseriate and biseriate, consisting of parenchyma. Axial tracheids bear a single row of bordered pits with subcircular apertures. The crossfields contain one or two half-bordered pit pairs with oblique elliptic apertures on the tracheid side. This wood may have affinity with Cupressaceae s.l. (including Taxodiaceae). A second wood type consists of thick-walled tracheids, some axial parenchyma, and uniseriate rays with a height of 36 or more cells. Bordered pits, occurring in one, two, or possibly more rows along the tracheids, are characterized by deep pit canals resembling compressed funnels and shallower pit cavities. One or two half-bordered pit pairs were observed in the crossfields. This wood type appears to show affinity with Podocarpaceae, or possibly Cupressaceae. A third wood type shows affinity to Podocarpaceae, and a possible fourth wood type is similar to the second type but has shallower, less compressed, pit canals. The diversity of conifer wood, along with that of other conifer fossils, twigs, leaves, seed cones, and seeds, from the Tertiary basins of Northern Thailand, provides evidence that the conifers in the Recent of Thailand represent a relict of a once larger number of conifers.

Key words: charcoalified wood, conifer, Cupressaceae, Podocarpaceae, Thailand