New Australovenator Hind Limb Elements Pertaining to the Holotype Reveal the Most Complete Neovenatorid Leg

Matt A White,David A Elliott,Sarah J Wooldridge,Scott A Hocknull,Alex G Cook,David G Barnes,George H K Sinapius,Roger B J Benson,Stephen F Poropat,Travis R Tischler,Trish Sloan

doi:10.1371/journal.pone.0068649

Abstract

We report new skeletal elements pertaining to the same individual which represents the holotype of Australovenator wintonensis, from the ‘Matilda Site’ in the Winton Formation (Upper Cretaceous) of western Queensland. The discovery of these new elements means that the hind limb of Australovenator is now the most completely understood hind limb among Neovenatoridae. The new hind limb elements include: the left fibula; left metatarsal IV; left pedal phalanges I-2, II-1, III-4, IV-2, IV-3; and right pedal phalanges, II-2 and III-1. The detailed descriptions are supported with three dimensional figures. These coupled with the completeness of the hind limb will increase the utility of Australovenator in comparisons with less complete neovenatorid genera. These specimens and the previously described hind limb elements of Australovenator are compared with other theropods classified as neovenatorids (including Neovenator, Chilantaisaurus, Fukuiraptor, Orkoraptor and Megaraptor). Hind limb length proportion comparisons indicate that the smaller neovenatorids Australovenator and Fukuiraptor possess more elongate and gracile hind limb elements than the larger Neovenator and Chilantaisaurus. Greater stride lengths to body size exist in both Fukuiraptor and Australovenator with the femur discovered to be proportionally shorter the rest of the hind limb length. Additionally Australovenator is identified as possessing the most elongate metatarsus. The metatarsus morphology varies with body size. The larger neoventorids possess a metatarsus with greater width but shorter length compared to smaller forms.

Highlights

The skeletal remains of Australovenator wintonensis [1] were discovered interspersed with the remains of a sauropod dinosaur Diamantinasaurus matildae [1]
The fossils were excavated from Australian Age of Dinosaurs Locality 85 (AODL 85) – the ‘‘Matilda site’’ on Elderslie station, approximately 60km northwest of Winton, Queensland, Australia
Substantial skeletal remains of Austraovenator were reported in the description of the holotype [1], the preparation of concretions from AODL 85 continued following the publication of the paper, yielding new forelimb [11] and hind limb elements of Australovenator

Summary

Introduction

The skeletal remains of Australovenator wintonensis [1] were discovered interspersed with the remains of a sauropod dinosaur Diamantinasaurus matildae [1]. The fossils were excavated from Australian Age of Dinosaurs Locality 85 (AODL 85) – the ‘‘Matilda site’’ on Elderslie station, approximately 60km northwest of Winton, Queensland, Australia. The deposit was first identified by the landowners, who discovered large fragmented sauropod remains exposed on the surface. Excavation of the site demonstrated that the bones were being reworked from gunmetal bluecoloured clay, rich in plant debris (Figure 1; Figure S1). Substantial skeletal remains of Austraovenator were reported in the description of the holotype [1], the preparation of concretions from AODL 85 continued following the publication of the paper, yielding new forelimb [11] and hind limb elements of Australovenator

Methods

Results

Conclusion