Objective Despite a large number of bird fossils in the Jehol Biota, Mesozoic bird records from other parts of China are dominated by tracks. Late Cretaceous bird tracks are rarely found in China. Reliable reports so far include a Dongyangornipes and Koreanaornis assemblage of early Late Cretaceous age from Dongyang City, Zhejiang Province, China (Azuma et al., 2013). Buckley et al. (2016) consider Dongyangornipes sinensis a subjective junior synonym of Uhangrichnus chuni. Type Uhangrichnus chuni (Yang et al. 1995; Lockley et al., 2012) from the Uhangri Formation, Hwangsan Basin of South Korea is Late Cretaceous in age, and the trackmaker was a web-footed avian. In 1972, the Tibet Geology Bureau discovered a series of Late Cretaceous dinosaur tracks at the Dongga coal mine. But they were subsequently considered to be Cenozoic large bird footprints (Xing et al., 2013). Bird footprints were also reported from Late Cretaceous deposits in the Gupei Basin in Anhui Province (Jin and Yan, 1994), but then re-interpreted as an Early Cretaceous record (Xing et al., 2018). In July 2017, a team from China University of Geosciences (Beijing) found some invertebrate traces and vertebrate tracks on a hill (GPS: 31°13'53.35"N, 95° 57'18.95"E, altitude 3739 m) east of Jue’en Township, Dingqing County, Changdu City, Tibet Autonomous Region. According to the 1:250000 scale geologic mapping of Dingqingfu area (No. H46C001004), the Jue’en site belongs to the Upper Cretaceous Bada Formation, consisting of interbedded purple red siltstone, fine-grain lithic quartz sandstone, micrite and dolomicrite in variable thickness, and has yielded abundant gastropod fossils (Wang et al., 2013). Results Koreanaornipodidae Lockley et al., 2006 Koreanaornis Kim, 1969 Type ichnospecies. Koreanaornis hamanensis Kim, 1969, Lockley et al., 1992 emend. Diagnosis. Small, tetradactyl bird tracks with small hallux impressions occasionally present. Digit traces typically separate (i.e., not connected proximally). Claw traces variably present, slender, and obscure. Trackways exhibit inward (positive) rotation of the tracks. Tracks wider than long, with widths ranging from 2.5ԟ4.4 cm. Divarication between digits II and IV averaging about 120° (Lockley et al., 1992). Material. Two natural molds cataloged as JE-B1-1L and 1R, from the Jue’en track site (Fig. 1) and stored in China University of Geosciences (Beijing). Description. Small, tridactyl bird tracks lacking hallux impressions. JE-B1-1L lacks digit IV trace. JE-B1-1R is well-preserved. Digit III trace is the longest; digit II trace is the widest, and digit IV trace only preserves its distal end. Digital pad impressions are absent. The digit II trace is broader than those representing digits III and IV. The maximum length of JE-B1-1L is 2.7 cm and maximum width is 2.7 cm. The length:width ratio is 1.0. The average divarication angle between digits II and IV is 92°. The divarication angles between digits II and III (56°) are larger than those between digits III and IV (36°). The pace First Report of Avian Tracks from the Cretaceous of Tibet, China XING Lida 1, 2, 3 , CHOU Chunyong 2, * , Martin G. LOCKLEY 4 , YANGCHEN Dolkar 5 , CHEN Xingru 2 , MA Xinghong 6 , ZHOU Wenjun 2 and XU Hantian 2 1 State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China 2 School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China 3 State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China 4 Dinosaur Tracks Museum, University of Colorado Denver PO Box 173364, Denver, CO 80217, USA 5 School of Geophysics and Information Technology, China University of Geosciences, Beijing 100083, China 6 School of Land Science and Technology, China University of Geosciences, Beijing 100083, China Vol. 91 No. 6 pp.2312–2313 ACTA GEOLOGICA SINICA (English Edition) Dec. 2017 * Corresponding author. E-mail: chouchuny@cugb.edu.cn © 2017 Geological Society of China Research Advances