Acta Palaeontologica Polonica

A large predatory archosaur from the Late Triassic of Poland

Grzegorz Niedźwiedzki, Tomasz Sulej, and Jerzy Dzik

Acta Palaeontologica Polonica 57 (2), 2012: 267-276 doi: http://dx.doi.org/10.4202/app.2010.0045

We describe a new large predatory archosaur, Smok wawelski gen. et sp. nov., from the latest Triassic (latest Norian–early Rhaetian; approximately 205–200 Ma) of Lisowice (Lipie Śląskie clay−pit) in southern Poland. The length of the reconstructed skeleton is 5–6 m and that of the skull 50–60 cm, making S. wawelski larger than any other known predatory archosaur from the Late Triassic and Early Jurassic of central Europe (including theropod dinosaurs and “rauisuchian” crurotarsans). The holotype braincase is associated with skull, pelvic and isolated limb−bones found in close proximity (within 30 m), and we regard them as belonging to the same individual. Large, apparently tridactyl tracks that occur in the same rock unit may have been left by animals of the same species. The highly autapomorphic braincase shows large attachment areas for hypertrophied protractor pterygoideus muscles on the lateral surface and a wide, funnel−like region between the basal tubera and basipterygoid processes on the ventral surface. The skeleton (cranial and postcranial) possesses some features similar to those in theropod dinosaurs and others to those in large crocodile−line archosaurs (“rauisuchians”), rendering phylogenetic placement of S. wawelski difficult at this time.

Key words: Archosauria, “Rauisuchia”, Dinosauria, Norian-Rhaetian, Late Triassic, Poland.

Grzegorz Niedźwiedzki [gniedzwiedzki@biol.uw.edu.pl], Institute of Zoology, University of Warsaw, Banacha 2, PL-02-097 Warszawa, Poland and Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University Norbyvägen 18A SE−752−36 Uppsala, Sweden; Tomasz Sulej [sulej@twarda.pan.pl], Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warszawa, Poland; Jerzy Dzik [dzik@twarda.pan.pl], Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warszawa, Poland and Institute of Zoology, University of Warsaw, Banacha 2, 02-097 Warszawa, Poland.