Microvertebrates from limestones near the Burmese border town of Mae Sam Lap, northern Thailand, are dated as late Famennian by associated conodonts. The fauna contains the chondrichthyans Thrinacodus ( Harpagodens) ferox, Symmorium? sp., " Cladodus," cf. C. acutus, and two new taxa, Phoebodus australiensis, sp. nov., and Siamodus janvieri, gen. et sp. nov. Several types of chondrichthyan scales, actinopterygian scales and teeth, and rare acanthodian scales also occur in the fauna. Phoebodus australiensis, sp. nov., is also recognized from Australia and South China; Siamodus, gen. nov., is also recognized from the Late Devonian of South China. Thrinacodus ferox appears in the Late Devonian of Australia, South China, and Thailand, predating the occurrence of this species in Europe and North America (Carboniferous). These data suggest close affinity between the Shan-Thai, East Gondwana, and South China Terranes at the end of the Devonian.