ASGP (2020), vol. 90: 1–26

LARGE TRIDACTYL DINOSAUR TRACKS FROM THE EARLY JURASSIC OF SOUTHERN GONDWANA – UPPERMOST ELLIOT FORMATION, UPPER MOYENI, LESOTHO

Miengah ABRAHAMS (1), Lara SCISCIO (1,2), Mhairi REID (1,3), T’Nielle HAUPT (1) & Emese M. BORDY (1)*

1) Department of Geological Sciences, University of Cape Town, Rondebosch 7701, South Africa; e-mails: miengah.abrahams@uct.ac.za; reid.mhairi@gmail.com; l.sciscio@gmail.com; tnielleh@gmail.com; emese.bordy@uct.ac.za
2) Current address: Department of Geology, University of Johannesburg, Kingsway and Auckland Park, 2006 Johannesburg, South Africa
3) Current address: Department of Geology, University of Oxford, Oxford, England
* Corresponding author

Abrahams, M., Sciscio L., Reid, M., Haupt, T. & Bordy, E. M., 2020. Large tridactyl dinosaur tracks from the Early Jurassic of southern Gondwana – uppermost Elliot Formation, Upper Moyeni, Lesotho. Annales Societatis Geologorum Poloniae, 90: 1 – 26.

Abstract: A new ichnosite in southwest Lesotho (Upper Moyeni, Quthing District) is located within the uppermost part of the highly fossiliferous Elliot Formation, ~35 m below the conformably overlying Clarens Formation and ~65 m above the world-renowned Lower Moyeni ichnosite. While the Lower Moyeni site preserves diverse Early Jurassic ichnofossils, the ichnites at Upper Moyeni comprise one vertebrate burrow and ~50 tridactyl tracks with footprint lengths between 15 and 51 cm. Many of the tracks preserve digital pad impressions, claw marks and displacement rims, all related to substrate conditions. The morphometric parameters of the Upper Moyeni tracks are consistent with Grallator, Eubrontes and Kayentapus. Several larger tracks with footprint lengths > 40 cm are Kayentapus-like and Eubrontes-like, and are comparable to previously described very large theropods tracks with lengths > 50 cm from the uppermost Elliot and Clarens formations. On the basis of sedimentological and ichnological evidence, the Upper Moyeni ichnofossils were formed in a palaeolandscape with small rivers and shallow lakes by burrowing tetrapods and a variety of bipedal dinosaurs (theropods), some of which were up to 7–8 m in body length. The Upper Moyeni tracks, together with the other very large tracks from coeval locations in southern Africa, collectively highlight the tendency towards increasing diversity in size of tridactyl tracks and by extension theropod trackmaker body size body size, which runs in tandem with the increasing diversity of non-sauropod, sauropodomorph body fossils in the Sinemurian–Pliensbachian of southern Gondwana.

Manuscript received 19 May 2020, accepted 13 June 2020