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Theropod tracks from Lower Jurassic of Gulin, China

Ben Creisler

A new paper:

Li-Da Xing, Martin G. Lockley, Jian-Ping Zhang, Hendrik Klein, Susanna
B. Kümmell, W. Scott Persons Iv & Hui Dai (2015)
Theropod tracks from the Lower Jurassic of Gulin area, Sichuan Province, China.
Palaeoworld (advance online publication)

The Jiaoyuan tracksite in the Gulin area of Sichuan Province, China
represents a typical saurischian-dominated assemblage with trackways
of theropods and sauropods. They occur in the Lower Jurassic Da’anzhai
Member of the Ziliujing Formation, a sandstone-siltstone succession of
fluvial origin and deposited in the southern Sichuan Basin. Four
trackways as well as isolated tracks of theropods are documented and
analyzed in this first part a study of sauropod tracks will follow
elsewhere. Two morphotypes and size-classes, respectively, can be
observed. The larger one is 25 to 34 cm in length and shows weak to
moderate mesaxony. The smaller is 7 to 15 cm in length and moderately
mesaxonic. Despite a few similarities with the ichnogenus Kayentapus,
the former is assigned here to Eubrontes, well known from Lower
Jurassic assemblages, in North America, Europe, and southern Africa.
The smaller morphotype resembles typical Grallator tracks except in
its wider digit divarication and the metatarsophalangeal pad IV being
positioned in line with the long-axis of digit III, similar to
Jialingpus described, for example, from Upper Jurassic deposits of
Sichuan. A relatively wide digit divarication in Grallator-type tracks
is apparently common in Jurassic assemblages of China and may
represent a distinct feature related to provinciality of theropod
faunas in this region.