New material of turtles from the Upper Jurassic of Phu Noi, NE Thailand: Phylogenetic implications

Abstract

New shell material of Phunoichelys thirakhupti and Kalasinemys prasarttongosothi are reported from their type locality, Phu Noi site, Khorat Plateau, NE Thailand. These new specimens complete our knowledge of their anatomy. Intraspecific and ontogenetic variations are observed in P. thirakhupti; and reconstruction of the shell is provided for both species. Both Phunoichelys and Kalasinemys are aquatic turtles, but their shell morphology is distinct, suggesting different mode of life. A phylogenetic scenario is presented where the previously character based Xinjiangchelyidae appear to be paraphyletic, suggesting more phylogenetically diverse lineages were present in Eastern and South-east Asia during the Jurassic.