[F] Phu Kradung Formation - Thailand
Thailand
The Phu Kradung Formation, a stratigraphic unit formally proposed by Ward and Bunnag [1964], is now considered as forming the base of the Mesozoic Khorat Group of northeastern Thailand [Racey et al., 1996]. Its exact age has been a matter of discussion, because, like the other formations of the Khorat Group, it contains few fossils that can easily be used for biostratigraphic purposes, no marine ingressions, and no volcanic components that could be used for radiometric dating. Although originally considered as Late Triassic to Early Jurassic in age [Ward and Bunnag, 1964], the occurrence of the fairly advanced mesosuchian crocodilian Sunosuchus showed that it could not be older than Jurassic [Buffetaut and Ingavat, 1980]. In their general review of the Khorat Group, Racey et al. [1996] considered the Phu Kradung Formation as Late Jurassic or (more probably) Early Cretaceous in age. Further palynological studies suggest that the Phu Kradung Formation may belong to the Early Cretaceous (A. Racey, pers.com). The possible implications of the fossil described here for the age of the Phu Kradung Formation are discussed below. Thedinosaur assemblage from the Phu Kradung Formation includes euhelopodid sauropods [Buffetaut et al., 2002; Buffetaut and Suteethorn, 2004], stegosaurs [Buffetaut et al., 2001] a sinraptorid theropod (2007) and yet undescribed small ornithopods. Buffetaut, E. & Suteethorn, V. (2007)
Sinraptorid sp. (Buffetaut, E. & Suteethorn, V. 2007)
Thyreophoran vertebrae - Ornithischia Thyreophora - Jurassic Late