New Middle Jurassic mammaliaform tracks from northern Shaanxi Province, China

The Middle Jurassic Yan’an Formation in Zizhou County, Shaanxi Province, China, preserves abundant vertebrate ichnofossils. In 2019, several morphologically distinctive small tetradactyl and pentadactyl tracks, as well as possible pterosaur tracks, were discovered at the Wangzhuang and Longweimao tracksites. These tracks were documented using 3D photogrammetry and morphological comparison suggests that these tracks share morphological similarities with Ameghinichnus . Their distinctive features indicate that they may represent an undetermined ichnospecies within this genus; therefore, they are provisionally referred to Ameghinichnus isp., which represents the first record of Ameghinichnus in Asia. The pterosaur tracks preserved alongside the mammaliaform tracks may represent one of the earliest known pterosaur ichnofossils in China. Palaeoecological evidence suggests that Ameghinichnus isp. was produced by small, agile mammaliaforms inhabiting low-energy fluvial–lacustrine environments. This discovery extends the spatiotemporal range of Ameghinichnus , enriches the Jurassic mammaliaform ichnological record of East Asia and provides new insights into their palaeoecology and early evolutionary history.