Dinosaur footprint assemblage from the Lower Cretaceous Khok Kruat Formation,Khorat Group,

Dinosaur footprint assemblage from the Lower Cretaceous Khok Kruat Formation,Khorat

Group,northeastern Thailand

Shohei

Kozu;Apsorn

Sardsud;Doungrutai

Saesaengseerung;Cherdchan

Pothichaiya;Sachiko Agematsu;Katsuo Sashida

【期刊名称】《地学前缘(英文版)》 【年(卷),期】2017(008)006

【摘要】The Khok Kruat Formation is the upper part of the Khorat Group, which consists of upper Lower Cretaceous non-marine sedimentary rocks in northeastern Thailand.Many dinosaur footprints have been known from the upper Lower Cretaceous(Aptian-Albian)Khok Kruat Formation at the Huai Dam Chum (Tha Uthen) site, northeastern Thailand. Approximately 600 tracks occur in thin mudstone layer of the northern part of the outcrop at the Huai Dam Chum track site. Two types of footprints, small-sized theropod and crocodylomorph are imprinted with mud cracks and ripple marks on the thin mud layer. Most of footprints are referred to cf. Asianopodus, and are imprinted by small-sized theropoda, probably ornithomimosauria.Theropod tracks are mainly separated into two groups,Group A and Group B.From ichnological viewpoints,the small-sized theropod track assemblage indicates the herd behaviour and its idiosyncratic group composition.In particular,the histogram of size-frequency measurements of Group A