The past eight years have seen quite a few cases where purported Triassic dinosaurs actually turned out to be non-dinosaurian archosauriforms...Revueltosaurus, Shuvosaurus, Azendohsaurus... finally the dinosaurs get one back. Moreover there are no Jurassic or Chinese phytosaur specimens.
Barrett, P. M., and X. Xu. 2012. The enigmatic reptile Pachysuchus imperfectus Young, 1951 from the lower Lufeng Formation (Lower Jurassic) of Yunnan, China. Vertebrata PalAsiatica 50:151-159. [Free download here]
Abstract - Phytosaurs are generally considered to have become extinct at the end of the Triassic Period, but several records have suggested that they survived into the basal Jurassic in Europe and Asia. The Asian record consists of Pachysuchus imperfectus from the lower Lufeng Formation (?Hettangian-Sinemurian) of Yunnan, China. However, this specimen differs from phytosaurs in numerous aspects and is more likely a poorly preserved, indeterminate sauropodomorph dinosaur skull. The referred specimens of this species are also regarded as indeterminate, thereby removing the post-Triassic record of phytosaurs from Asia. The European records of Jurassic phytosaurs are also shown to be doubtful, suggesting that this clade was restricted to the Late Triassic.
Does expression of the toxA operon depend on ToxT as well as ToxA?
1 day ago in RRResearch