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Longest theropod trackway from East Asia

Ben Creisler

A new paper:

Lida Xing, Martin G. Lockley, Jianping Zhang, Hendrik Klein, Daniel
Marty, Guangzhao Peng, Yong Ye, Richard T. McCrea, W.Scott Persons IV
& Ting Xu (2015)
The longest theropod trackway from East Asia, and a diverse sauropod-,
theropod-, and ornithopod-track assemblage from the Lower Cretaceous
Jiaguan Formation, southwest China.
Cretaceous Research 56: 345-362

Here we report a large dinosaur tracksite from an extensive fluvial
sandstone surface in the Lower Cretaceous Jiaguan Formation of Sichuan
Province, China. The site contains over 250 individual tracks
comprising at least 18 recognizable trackways, including the longest
theropod trackway (cf. Eubrontes) known from China. This exceptional
theropod trackway consists of 81 successive footprints covering a
distance of 69 m. The tracks are well-preserved and are expressed both
as true tracks on the main “upper” surface and as transmitted
undertracks on a locally exposed “lower” bed. Also recorded are six
other theropod trackways, including small Grallator-like ichnites,
eight sauropod trackways (cf. Brontopodus), and three small ornithopod
(cf. Ornithopodichnus) trackways with a parallel orientation, which
may indicate gregarious behavior. Several trackways of a larger
theropod trackmaker show pes imprints with elongated traces of the
metatarsals, suggesting extramorphological (substrate-controlled)
variation and/or plantigrade posture, which is here interpreted as
indicating a change in gait assumed in response to deep and soft
sediment. The assemblage indicates a diverse dinosaur fauna in the
Lower Cretaceous Sichuan Basin with variously sized theropods,
sauropods, and ornithopods. The late occurrence of footprints of the
Grallator-Eubrontes plexus in Lower Cretaceous strata is further
evidence of the extended stratigraphic range of this morphotype and
the distinct palaeobiogeographic distribution of these trackmakers in
East Asia.