named troodontid that has been discovered in the Jehol Biota as a whole, with the first three other troodontids also originating from the Yixian Formation. With Jianianhualong and Sinusonasus representing "transitional" and more derived forms of troodontids compared to Mei and Sinovenator, the diversity of troodontids within the Jehol was appreciable. Asides from troodontids, the Yixian Formation also preserves a diverse assemblage of other animals, both dinosaurian and non-dinosaurian. The hadrosauroid Jinzhousaurus is known from Baicai Gou, the same locality as that of Jianianhualong, as is the maniraptoran Yixianosaurus as well as hundreds of specimens from the choristodere Hyphalosaurus. From elsewhere in the Dakangpu/Dawangzhangzi Beds, specimens have been discovered belonging to the birds Confuciusornis, Hongshanornis, Grabauornis, Liaoxiornis, Longicrusavis, Shanweiniao, Shenqiornis, and Zhongornis; the non-avialan theropod Sinosauropteryx; the ceratopsian Psittacosaurus; the pterosaur Cathayopterus; the lizards Dalinghosaurus and Yabeinosaurus; the choristoderes Hyphalosaurus and Monjurosuchus, of which the former is highly abundant; the turtle Manchurochelys; the mammals Acristatherium, Akidolestes, Chaoyangodens, Eomaia, Sinobaatar, and Sinodelphys; the frog Liaobatrachus; and fish, including Lycoptera (of which L. davidi is numerous), Peipiaosteus, and Protopsephurus. Environmentally, Jianianhualong lived in a lacustrine area, as evinced by the tuffaceous sandstone present throughout the Dawangzhangzi Beds. Like the rest of the Yixian Formation, the environment represented by these assemblages was seasonally semi-arid, with a low mean air temperature of . The local flora consists of a mixed assemblage of gymnosperms, such as Czekanowskia, Schizolepis, and the ephedroids Amphiephedra, Chengia, Ephedrites, and Liaoxia; and also early angiosperms, including Archaefructus, Hyrcantha (formerly Sinocarpus), Leefructus, and Potamogeton. Leefructus in particular is a eudicot, being among the earliest records of the group. See also Timeline of troodontid research 2017 in archosaur paleontology References Troodontids Feathered dinosaurs Aptian life Early Cretaceous dinosaurs of Asia Cretaceous China Fossils of China Yixian fauna Fossil taxa described in 2017 Taxa named by Xu Xing Taxa named by Philip J. Currie Taxa named by Lü Junchang