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Hadrosauriform track preserved in 3-D from Chongqing, China

From: Ben Creisler

A new paper in Acta Geologica Sinica:

XING Lida, Phil R. BELL, Jerald D. HARRIS & Philip J. CURRIE (2012)
An Unusual, Three-Dimensionally Preserved, Large Hadrosauriform Pes
Track from “Mid”-Cretaceous Jiaguan Formation of Chongqing, China.
Acta Geologica Sinica - English Edition 86: 304–312.
doi: 10.1111/j.1755-6724.2012.00660.x
pdf should be able at: http://www.xinglida.net/paper_list.htm

Three-dimensional tracks provide unique insights into the locomotor
mechanics of their track makers. An isolated, large hadrosauriform
print attributable to Caririchnium lotus from the “mid”-Cretaceous
Lotus track site (Jiaguan Formation) in China permits reconstruction
of the footfall, weight-bearing, and kick-off phases of the step
cycle. Large-scale modifications of the pes during the step cycle
indicate C. lotus trackmakers were capable of locomotory modifications
in response to substrate consistency beyond the “expected” shift
between bipedal and quadrupedal postures. An unusual curvature to the
trace of one of the outer digits indicates substantial transverse
mobility. The remaining digits demonstrate lesser degrees of
transverse movement accompanied by extension of the digits during
footfall. The absence of overprinted scale-scratch marks and toe drags
are consistent with a vertical kick-off of the pes and concomitant
flexion of the digits. This track suggests that pedal mobility in C.
lotus track makers was greater than previously suspected and has
implications for reconstructions of hadrosauriform locomotion.