First Report of Avian Tracks from the Cretaceous of Tibet, China

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).