Your heard it here first: Prorotodactylus trackmaker ‘most likely a lepidosaur,’ not a dinosauromorph

Cosesaurus matched to Rotodactylus from Peters 2000.
Figuure 1. Cosesaurus matched to Rotodactylus from Peters 2000.

Klein and Lucas 2021 wrote:
Trackmaker: Brusatte et al. (2011) and Niedżwiedzki et al. (2013) attributed Prorotodactylus to dinosauromorph trackmakers similar to the trackmaker of Rotodactylus (Haubold, 1999). However, archosauromorph and even lepidosauromorph trackmakers cannot be excluded (see also discussion in Klein and Niedżwiedzki, 2012). Indeed, given the great similarity of Protorodactylus and Rhynchosauroides (one of us SGL, considers both genera to be likely synonyms), a lepidosauromorph trackmaker seems most likely.”

Figure 1. Cosesaurus flapping - fast. There should be a difference in the two speeds. If not, apologies. Also, there should be some bounce in the tail and neck, but that would involve more effort and physics.
Figure 2. Cosesaurus flapping and running bipedally digitigrade, close to life size on a 72 dpi monitor.

Klein and Lucas did not cite Peters 2000, 2011,
who matched Rotodactylus tracks (Peabody 1948; Fig. 1) to the pes of the small lepidosaur precursor to pterosaurs, Middle Triassic Cosesaurus (Figs. 1, 2).

Brusatte SL, Niedźwiedzki G and Butler RJ 2010. Footprints pull origin and diversification of dinosaur stem lineage deep into Early Triassic. Proceedings of the Royal Society B. 278 (1708): 1107–1113.
Brusatte S 2018. The rise and fall of the dinosaurs. A new history of a lost world. Wm. Morrow. An imprint of HarperCollins Publishers. 404pp.
Klein H and Lucas SG 2021. The Triassic tetrapod footprint record. New Mexico Museum of Natural History & Science Bulletion 83.
Peabody FE 1948.  Reptile and amphibian trackways from the Lower Triassic Moenkopi formation of Arizona and Utah.  University of California Publications, Bulletin of the  Department of Geological Sciences 27: 295-468.
Peters D 2000. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification.Ichnos 18(2):114-141.


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