Title:
Tracking the Pliensbachian–Toarcian Karoo firewalkers: Trackways of quadruped and biped dinosaurs and mammaliaforms
Authors:
Bordy EM, Rampersadh A, Abrahams M, Lockley MG & Head HV
Citation:
Bordy, E.M., Rampersadh, A., Abrahams, M., Lockley, M.G., Head, H.V. (2020). Tracking the Pliensbachian - Toarcian Karoo firewalkers: Trackways of quadruped and biped dinosaurs and mammaliaforms. PLoS ONE 15(1): e0226847. https://doi.org/10.1371/journal.pone.0226847
From the abstract:
The Karoo igneous rocks represent one of the largest continental flood basalt events (by volume) on Earth, and are not normally associated with fossils remains. However, these Pliensbachian–Toarcian lava flows contain sandstone interbeds that are particularly common in the lower part of the volcanic succession and are occasionally fossiliferous. On a sandstone interbed in the northern main Karoo Basin, we discovered twenty-five tridactyl and tetradactyl vertebrate tracks comprising five trackways. The tracks are preserved among desiccation cracks and low-amplitude, asymmetrical ripple marks, implying deposition in low energy, shallow, ephemeral water currents. Based on footprint lengths of 2–14 cm and trackway patterns, the trackmakers were both bipedal and quadrupedal animals of assorted sizes with walking and running gaits. We describe the larger tridactyl tracks as “grallatorid” and attribute them to bipedal theropod dinosaurs, like Coelophysis, a genus common in the Early Jurassic of southern Africa.