The dicynodonts are an emblematic group of herbivorous therapsids, which survived the Permo-Triassic (P-Tr) crisis. Laotian dicynodonts from stratigraphically constrained beds, recently dated using the U-Pb zircon method, yield new insights into terrestrial faunas of Southeast Asia during latest Permian and the earliest Triassic. Summarily described, they were attributed to the genus Dicynodon. We provide a new phylogenetic analysis for Laotian dicynodonts, based on three well-preserved skulls indicating that they belong to two new species: Counillonia superoculis gen. et sp. nov. and Repelinosaurus robustus gen. et sp. nov. Our phylogenetic analysis within Dicynodontia indicate that 1) Counillonia is closely related to some "Dicynodon"-grade taxa; and 2) Repelinosaurus is a kannemeyeriiform. The phylogenetic affinities of these new Laotian dicynodonts allow discussing the survivorship of multiple lineages (Kannemeyeriiformes and "Dicynodon"-grade dicynodontoids) across the P-Tr crisis. The Laotian dicynodonts also shed new light on the paleobiogeography of the Southeast Asia from the late Paleozoic to the early Mesozoic, particularly about the timing of collisions between the Indochina, the South China and the North China blocks. The presence of dicynodonts in Laos most likely in the Early Triassic thus implies that the connection between the Indochina Block and South China Block occurred no later than the latest Permian or earliest Triassic (i.e., when the dicynodonts provide direct evidence for a connection).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.