A reappraisal of the Cretaceous non-avian dinosaur faunas from Australia and New Zealand: evidence for their Gondwanan affinities

Abstract

It has often been assumed that Australasian Cretaceous dinosaur faunas were for the most part endemic, but with some Laurasian affinities. In this regard, some Australasian dinosaurs have been considered Jurassic relicts, while others were thought to represent typical Laurasian forms or endemic taxa. Furthermore, it has been proposed that some dinosaurian lineages, namely oviraptorosaurians, dromaeosaurids, ornithomimosaurians and protoceratopsians, may have originated in Australia before dispersing to Asia during the Early Cretaceous. Here we provide a detailed review of Cretaceous non-avian dinosaurs from Australia and New Zealand, and compare them with taxa from other Gondwanan landmasses. Our results challenge the traditional view of Australian dinosaur faunas, with the majority of taxa displaying affinities that are concordant with current palaeobiogeographic models of Gondwanan terrestrial vertebrate faunal distribution. We reinterpret putative Australian ‘hypsilophodontids’ as basal ornithopods (some of them probably related to South American forms), and the recently described protoceratopsians are referred to Genasauria indet. and Ornithopoda indet. Among Theropoda, the Australian pigmy ‘Allosaurus’ is referred to the typical Gondwanan clade Abelisauroidea. Similarities are also observed between the enigmatic Australian theropod Rapator, Australovenator and the South American carcharodontosaurian Megaraptor. Timimus and putative oviraptorosaurians are referred to Dromaeosauridae. The present revision demonstrates that Australia's non-avian Cretaceous dinosaurian faunas were reminiscent of those found in other, roughly contemporaneous, Gondwanan landmasses, and are suggestive of faunal interchange with these regions via Antarctica.

Keywords:

• Australia
• New Zealand
• Cretaceous
• Gondwana
• Dinosauria

Acknowledgements

J. I. Canale and P. A. Gallina participated in the first stages of this research with FLA. Comments and data provided by R. E. Molnar are gratefully appreciated. P. M. Barrett, R. E. Molnar, P. D. Taylor and two anonymous reviewers provided comments that improved the quality of the manuscript, while A. G. Martinelli, M. Herne, M. C. Lamanna, L. G. Leahey, P. J. Makovicky, N. Smith, T. H. Rich and P. Vickers-Rich provided useful discussion. The following people allowed us to study specimens under their care: F. E. Novas, J. O. Calvo, J. Canale, R. Coria, P. Puerta, D. Pol, J. Powell, A. Kramarz, S. Apesteguía, S. Martin, E. Vaccari (Argentina), C. Consoli, A. Cook, D. Elliott, S. Hocknull, R. Jones, L. Kool, J. Long, D. Pickering, T. H. Rich, K. Spring, J. D. Stilwell, P. Vickers-Rich (Australia), D. Brinkman, P. Holroyd, W. Joyce, B. Masek, C. Mehling, M. A. Norell, K. Padian, P. C. Sereno (USA), D. Schwarz-Wings (Germany), L. Steel, S. Chapman, and P. Barrett (England). T. H. Rich and J. Long kindly provided photographs of Timimus and Qantassaurus. C. Consoli also needs to be thanked for his assistance with aspects of Fig. 1, and A. O'Toole and L. Leahey for their part in photographing the Marathon Mimni. Research conducted by MDE was partially funded by The Jurassic Foundation, the Doris and Samuel P. Welles Grant of the UCMP, and the Jackson School of Geosciences Student Member Travel Grant of the Society of Vertebrate Paleontology. Research conducted by SWS formed part of a Rea Postdoctoral Fellowship at the Carnegie Museum of Natural History and was funded in part by the Australian Research Council (LP0347332 and LP0776851) and The University of Queensland, in association with Isisford Shire Council, Winton Shire Council, Land Rover Australia, the Queensland Museum and Carnegie Museum of Natural History.