Journal of Palaeogeography     2019 8 (2):  198-208    ISSN: 2095-3836  CN: 10-1041/P The first theropod tracks from the Middle Jurassic of Gansu, Northwest China: New and rare evidence of quadrupedal progression in theropod dinosaurs Da-Qing Li1, Li-Da Xing2,3, Martin G. Lockley4, Anthony Romilio5, Jing-Tao Yang1, Long-Feng Li1 1 Institute of Vertebrate Paleontology and College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070, Gansu Province, China.; 2 School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China.; 3 State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, China.; 4 Dinosaur Trackers Research Group, University of Colorado Denver, PO Box 173364, Denver, CO 80217, USA.; 5 School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.; Received: 2018-10-02  Revised: null  Online: null Supporting info null