Ornithopod diversity in the Griman Creek Formation (Cenomanian), New South Wales, Australia.

Phil R Bell,Tom Brougham,Elizabeth T Smith,Matthew C Herne

doi:10.7717/peerj.6008

Phil R Bell, Tom Brougham + Show 2 more

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https://doi.org/10.7717/peerj.6008

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Journal: PeerJ	Publication Date: Dec 4, 2018
Citations: 23	License type: CC BY 4.0

Affiliation: University of New England, University of Queensland

Abstract

During the Early Cretaceous, dinosaur communities of the Australian-Antarctic rift system (Eumeralla and Wonthaggi formations) cropping out in Victoria were apparently dominated by a diverse small-bodied ‘basal ornithopod’ fauna. Further north, in Queensland (Winton and Mackunda formations), poorly-represented small-bodied ornithopods coexisted with large-bodied iguanodontians. Our understanding of the ornithopod diversity from the region between the Australian-Antarctic rift and Queensland, represented by Lightning Ridge in central-northern New South Wales (Griman Creek Formation), has been superficial. Here, we re-investigate the ornithopod diversity at Lightning Ridge based on new craniodental remains. Our findings indicate a diverse ornithopod fauna consisting of two-to-three small-bodied non-iguanodontian ornithopods (including Weewarrasaurus pobeni gen. et sp. nov.), at least one indeterminate iguanodontian, and a possible ankylopollexian. These results support those of previous studies that favour a general abundance of small-bodied basal ornithopods in Early to mid-Cretaceous high-latitude localities of southeastern Australia. Although these localities are not necessarily time-equivalent, increasing evidence indicates that Lightning Ridge formed a ‘meeting point’ between the basal ornithopod-dominated localities in Victoria and the sauropod-iguanodontian faunas in Queensland to the north.

Highlights

Small, bipedal neornithischian dinosaurs, traditionally referred to as ‘hypsilophodontids’ or ‘basal ornithopods’, are typically rare in most Cretaceous deposits, globally (Brown, Boyd & Russell, 2011; Brown et al, 2013)
The Aptian–Albian aged deposits of southeastern Australia have yielded an unusual preponderance of these enigmatic animals (Rich & Vickers-Rich, 1989, 1999)
A reassessment of neornithischian craniodental remains from the Griman Creek Formation (GCF) yields new insights into the diversity of ornithopods at Lightning Ridge (Table 1)

Summary

Introduction

Bipedal neornithischian dinosaurs, traditionally referred to as ‘hypsilophodontids’ or ‘basal ornithopods’, are typically rare in most Cretaceous deposits, globally (Brown, Boyd & Russell, 2011; Brown et al, 2013). The Aptian–Albian aged deposits of southeastern Australia have yielded an unusual preponderance of these enigmatic animals (Rich & Vickers-Rich, 1989, 1999). From the state of Victoria alone (Fig. 1C), four locally endemic genera have been described, including Atlascopcosaurus loadsi (Rich & Vickers-Rich, 1989), Diluvicursor pickeringi (Herne et al, 2018), and. How to cite this article Bell PR, Herne MC, Brougham T, Smith ET. Ornithopod diversity in the Griman Creek Formation (Cenomanian), New South Wales, Australia.

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