New discovery of dinosaur footprints in the Upper
Jurassic-Lower Cretaceous Houcheng Formation at Shangyi，
northwestern Hebei Province and its
biogeographical implications
Liu Yongqing, Kuang Hongwei, Peng Nan, Xu Huan, Chen Jun, Xu Jialin, Liu Hai, Zhang Peng
JOURNAL OF PALAEOGEOGRAPHY . 2012, (5): 617 -627 .  DOI: 10.7605/gdlxb.2012.05.007