Detail of Sauropod tracks, Large scale bar 50 cm, small scale bar, 20 cm.Plan of the tracks. theropod (white arrows, T1-6), sauropod (black arrows, S1-5), and pterosaur (stippled arrows, P).
Diverse dinosaur-, pterosaur-, and bird-track assemblages from the Hakou Formation, Lower Cretaceous of Gansu Province, northwest China
Jianping Zhang, Daqing Lib, Minglu Li, Martin G. Lockley, Z. Bai.
Volume 27, Issue 1 , February 2006, Pages 44-55
http://dx.doi.org/10.1016/j.cretres.2005.10.006 (free full text as part of sample issue - lots of other interesting stuff)