Mesozoic terrestrial biota west of the Chiang Mai suture (Mae Sot Basin, western Thailand)

Abstract

A new Mesozoic fossiliferous locality was discovered in the Mae Sot Basin, western Thailand. Ginglymodian fish scales and bones are reported, as well as wood (Brachyoxylon sp.) and leafy twigs (cf. Cupressinocladus sp.). These are associated with Skolithosand Scoyeniaichnofacies. The biotic remains were deposited in an anoxic fluvial environment and wood underwent humification. Fossil wood specimens show a wide range of composition, ranging from nearly pure carbon to mixtures of coal and siliceous sediment. The limited fossil record makes biogeographical comparisons and stratigraphic deductions difficult. It is however the first time that terrestrial Mesozoic biota is reported from the Shan-Thai terrane west of the Chiang Mai suture and north of the Three Pagoda fault. Further research in and around this locality may refine our still fragmentary knowledge of Mesozoic continental ecosystems west of the Nan-Uttaradit suture.