title: Nothosaur foraging tracks from the Middle Triassic of southwestern China.
abstract: The seas of the Mesozoic (266-66 Myr ago) were remarkable for predatory marine reptiles, but their modes of locomotion have been debated. One problem has been the absence of tracks, although there is no reason to expect that swimmers would produce tracks. We report here seabed tracks made by Mesozoic marine reptiles, produced by the paddles of nothosaurs (Reptilia, Sauropterygia) in the Middle Triassic of the Luoping localities in Yunnan, southwestern China. These show that the track-making nothosaurs used their forelimbs for propulsion, they generally rowed (both forelimbs operating in unison rather than alternately), and the forelimb entered medially, dug in as the paddle tip gained purchase, and withdrew cleanly. These inferences may provide evidence for swimming modes, or it could be argued that the locomotory modes indicated by the tracks were restricted to such contact propulsion. Such punting behaviour may have been used to flush prey from the bottom muds.
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Qiyue
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Wen
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Shixue
authors.initials: S
authors.lastname: Hu
authors.affiliation: School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Benton
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Changyong
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xie
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Lü
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Huang
authors.affiliation: School of Biological Sciences, Flinders University, PO Box 2100, Adelaide, South Australia 5001, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Choo
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Zhong-Qiang
authors.initials: ZQ
authors.lastname: Chen
authors.affiliation: Chengdu Center of China Geological Survey, Chengdu 610081, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Opto-Electronics, Sichuan University, Chengdu 610065, China.
authors.forename: Qican
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002681:China; D025061:Dinosaurs / Q000502:physiology*; D005247:Feeding Behavior