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Re-description of partially collapsed Early Cretaceous dinosaur tracksite in China



Ben Creisler
bcreisler@gmail.com

A new paper:

Lida Xing, Martin G. Lockley, Daniel Marty, Laura Piñuela, Hendrik
Klein, Jianping Zhang, W. Scott Persons (2015) [2014]
Re-description of the partially collapsed Early Cretaceous Zhaojue
dinosaur tracksite (Sichuan Province, China) by using previously
registered video coverage.
Cretaceous Research 52(A): 138–152
DOI: 10.1016/j.cretres.2014.09.010
http://www.sciencedirect.com/science/article/pii/S0195667114001748



A re-description of the Early Cretaceous Zhaojue dinosaur tracksite
(Sichuan Province, China) is the major focus of the present work. The
tracksite is located in an active copper mine, and a dinosaur
track-bearing surface of about 1500 m2 (named tracksite I) initially
discovered in 1991, has since almost completely collapsed due to
ongoing quarry activities. Only about 5% of the initial surface still
remains in place (named “remaining tracksite”), while due to the
collapse a few new but rather poorly-preserved tracks were unearthed
on an underlying level. While the tracks still in place were studied
using common field techniques, a schematic tracksite map of the
collapsed surface was drawn based on a “corrected orthophotograph”
that was generated from overview photographs and from video frames.
Fortunately, the resolution of some of the close-up video frames is
sufficiently high to observe general track morphology, and to
re-interpret previously wrongly identified trackways. Here, we report
a quite diverse ichnocoenosis consisting of sauropod, ornithopod,
theropod, and pterosaur trackways and isolated tracks. The sauropod
trackways belong to the Brontopodus-type and were possibly left by
medium-sized titanosaurs. One of the sauropod trackways turns around
and makes an astonishingly narrow turn of more than 180° with very
pronounced “off-tracking” of the manus with respect to the pes. Such
unusual trackways are important for the reconstruction of sauropod
locomotion. The theropod trackways were left by small and medium-sized
animals with the imprint morphology being similar to that of the
ichnogenera Grallator and Eubrontes. Large tridactyl tracks with blunt
toes are tentatively identified as ornithopod tracks and may be
described as Caririchnium-type tracks. Pterosaur tracks can be
assigned to Pteraichnus. The association of pterosaur with small
theropod tracks is rather unusual, and this tracksite further
corroborates the frequent presence of large ornithopods in inland
environmental settings.