Archival data provides insights into the ambiguous track-maker gait from the Lower Jurassic (Sinemurian) Razorback beds, Queensland, Australia: evidence of theropod quadrupedalism?

ABSTRACT

The ichnological and palaeobiological interpretation of the first dinosaur tracks described from the Lower Jurassic (Sinemurian) Razorback beds, anthropogenic ‘fireclay caverns’ of Mount Morgan, Australia, is reviewed. This track sequence of two size categories has been widely accepted as having been formed by a theropod walking in an uncharacteristic quadrupedal stance. However, the morphology of the purported manus impression remained ambiguous due to the poor reproduction quality of the original image data. Here, we present previously unpublished archival photographic and replica material of this track surface. These clearly show the morphological details of the track series that are consistent with registration by two different sized bipedal track-makers. Overall, our findings illustrate that retained archival data can be pivotal in the resolution of palaeoichnological obscurities.

KEYWORDS:

• Razorback beds
• Lower Jurassic (Sinemurian)
• Australia
• dinosaur tracks
• quadrupedal

Acknowledgments

The authors thank Jens Lallasack, Diego Castanera, and an anonymous reviewer for constructive comments and helpful reviews. We would like to thank the staff of the Department of Natural Resources, Mines and Energy, Queensland Government Nicole Booth, Oskar Kadletz, Samantha Pegg, and Margaret Gigli for discussions regarding site access and permission to republish a supplementary photograph from Queensland Government Mining Journal. Our thanks to John Steinberger for insights into the importance the ‘fireclay caverns’ provide regional tourism. We also thank the staff of the Queensland Museum, Andrew Rozefelds and Kristen Spring for access to the ex-situ boulder containing Anomoepus (QMF25612) from the Lower Jurassic (Sinemurian) Precipice Sandstone, Carnarvon Gorge.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

The authors received no specific funding for this work.