Alex G. Cook

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

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.

Forearm Range of Motion in Australovenator wintonensis (Theropoda, Megaraptoridae)

The hypertrophied manual claws and modified manus of megaraptoran theropods represent an unusual morphological adaptation among carnivorous dinosaurs. The skeleton of Australovenator wintonensis from the Cenomanian of Australia is among the most complete of any megaraptorid. It presents the opportunity to examine the range of motion of its forearm and the function of its highly modified manus. This provides the basis for behavioural inferences, and comparison with other Gondwanan theropod groups. Digital models created from computed tomography scans of the holotype reveal a humerus range of motion that is much greater than Allosaurus, Acrocanthosaurus, Tyrannosaurus but similar to that of the dromaeosaurid Bambiraptor. During flexion, the radius was forced distally by the radial condyle of the humerus. This movement is here suggested as a mechanism that forced a medial movement of the wrist. The antebrachium possessed a range of motion that was close to dromaeosaurids; however, the unguals were capable of hyper-extension, in particular manual phalanx I-2, which is a primitive range of motion characteristic seen in allosaurids and Dilophosaurus. During flexion, digits I and II slightly converge and diverge when extended which is accentuated by hyperextension of the digits in particular the unguals. We envision that prey was dispatched by its hands and feet with manual phalanx I-2 playing a dominant role. The range of motion analysis neither confirms nor refutes current phylogenetic hypotheses with regards to the placement of Megaraptoridae; however, we note Australovenator possessed, not only a similar forearm range of motion to some maniraptorans and basal coelurosaurs, but also similarities with Tetanurans (Allosauroids and Dilophosaurus).

The dentary of Australovenator wintonensis (Theropoda, Megaraptoridae); implications for megaraptorid dentition

Megaraptorid theropods were an enigmatic group of medium-sized predatory dinosaurs, infamous for the hypertrophied claw on the first manual digit. Megaraptorid dentition is largely restricted to isolated teeth found in association with skeletal parts; however, the in situ maxillary dentition of Megaraptor was recently described. A newly discovered right dentary pertaining to the Australovenator holotype preserves in situ dentition, permitting unambiguous characterisation of the dentary tooth morphology. The new jaw is virtually complete, with an overall elongate, shallow profile, and fifteen visible in situ teeth at varying stages of eruption. In situ teeth confirm Australovenator exhibited modest pseudoheterodonty, recurved lateral teeth with a serrate distal carina and reduced mesial carina, similar to other megaraptorids. Australovenator also combines of figure-of-eight basal cross-section with a lanceolate shape due to the presence of labial and lingual depressions and the lingual twist of the distal carina. Computed tomography and three-dimensional imagery provided superior characterisation of the dentary morphology and enabled an accurate reconstruction to a pre-fossilised state. The newly established dental morphology also afforded re-evaluation of isolated theropod teeth discovered at the Australovenator holotype locality and from several additional Winton Formation localities. The isolated Winton teeth are qualitatively and quantitatively similar to the in situ dentary teeth of Australovenator, but are also morphometrically similar to Abelisauridae, Allosauridae, Coelophysoidea, Megalosauridae and basal Tyrannosauroidea. Qualitative characters, however, clearly distinguish the teeth of Australovenator and the isolated Winton teeth from all other theropods. Evidence from teeth suggests megaraptorids were the dominant predators in the Winton Formation, which contrasts with other penecontemporaneous Gondwanan ecosystems.

The pes of Australovenator wintonensis (Theropoda: Megaraptoridae): analysis of the pedal range of motion and biological restoration

The pedal range of motion in Australovenator wintonensis is investigated to determine what influence soft tissue had on range of motion in the foot. Fortunately, the theropod pes shares a close morphology with extant large cursorial birds. Therefore, to better understand the pedal range of motion of Australovenator, the pedal range of motion of Dromaius novaehollandiae (commonly known as the emu) was analysed with and without soft tissue. We used a variety of innovative digital techniques to analyse the range of motion and biologically restore the Australovenator pes. Computed tomography scans of Dromaius pes in fully flexed and fully extended positions provided the soft tissue range of motion limits. The bone on bone range of motion of the same specimen was replicated following the removal of soft tissue. It was identified that there was an increase in range of motion potential with the removal of soft tissue. This variation provided a guide to develop the potential range of motion of a fully fleshed Australovenator pes. Additionally, the dissection of the Dromaius pes provided a guide enabling the replication of the corresponding soft tissue and keratin sheaths of the Australovenator pes.

Reappraisal of Austrosaurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s first named Cretaceous sauropod dinosaur

Poropat, S.F., Nair, J.P., Syme, C.E., Mannion, P.D., Upchurch, P., Hocknull, S.A., Cook, A.G., Tischler, T.R. & Holland, T. XX.XXXX. 2017. Reappraisal of Austrosaurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s first named Cretaceous sauropod dinosaur. Alcheringa 41, 543–580. ISSN 0311-5518 Austrosaurus mckillopi was the first Cretaceous sauropod reported from Australia, and the first Cretaceous dinosaur reported from Queensland (northeast Australia). This sauropod taxon was established on the basis of several fragmentary presacral vertebrae (QM F2316) derived from the uppermost Lower Cretaceous (upper Albian) Allaru Mudstone, at a locality situated 77 km west-northwest of Richmond, Queensland. Prior to its rediscovery in 2014, the type site was considered lost after failed attempts to relocate it in the 1970s. Excavations at the site in 2014 and 2015 led to the recovery of several partial dorsal ribs and fragments of presacral vertebrae, all of which clearly pertained to a single sauropod dinosaur. The discovery of new material of the type individual of Austrosaurus mckillopi, in tandem with a reassessment of the material collected in the 1930s, has facilitated the rearticulation of the specimen. The resultant vertebral series comprises six presacral vertebrae—the posteriormost cervical and five anteriormost dorsals—in association with five left dorsal ribs and one right one. The fragmentary nature of the type specimen has historically hindered assessments of the phylogenetic affinities of Austrosaurus, as has the fact that these evaluations were often based on a subset of the type material. The reappraisal of the type series of Austrosaurus presented herein, on the basis of both external morphology and internal morphology visualized through CT data, validates it as a diagnostic titanosauriform taxon, tentatively placed in Somphospondyli, and characterized by the possession of an accessory lateral pneumatic foramen on dorsal vertebra I (a feature that appears to be autapomorphic) and by the presence of a robust ventral mid-line ridge on the centra of dorsal vertebrae I and II. The interpretation of the anteriormost preserved vertebra in Austrosaurus as a posterior cervical has also prompted the re-evaluation of an isolated, partial, posterior cervical vertebra (QM F6142, the ‘Hughenden sauropod’) from the upper Albian Toolebuc Formation (which underlies the Allaru Mudstone). Although this vertebra preserves an apparent unique character of its own (a spinopostzygapophyseal lamina fossa), it is not able to be referred unequivocally to Austrosaurus and is retained as Titanosauriformes indet. Austrosaurus mckillopi is one of the oldest known sauropods from the Australian Cretaceous based on skeletal remains and potentially provides phylogenetic and/or palaeobiogeographic context for later taxa such as Wintonotitan wattsi, Diamantinasaurus matildae and Savannasaurus elliottorum. Stephen F. Poropat* [sporopat@swin.edu.au; stephenfporopat@gmail.com] Department of Chemistry and Biotechnology, Swinburne University of Technology, John St, Hawthorn, Victoria 3122, Australia; Jay P. Nair [j.nair@uq.edu.au; jayraptor@gmail.com] School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Caitlin E. Syme [caitlin.syme@uqconnect.edu.au] School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Philip D. Mannion [philipdmannion@gmail.com] Department of Earth Science and Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; Paul Upchurch [p.upchurch@ucl.ac.uk] Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK; Scott A. Hocknull [scott.hocknull@qm.qld.gov.au] Geosciences, Queensland Museum, 122 Gerler Rd, Hendra, Queensland 4011, Australia; Alex G. Cook [alex.cook@y7mail.com] School of Earth Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Travis R. Tischler [travisr.tischler@outlook.com] Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia; Timothy Holland [drtimothyholland@gmail.com] Kronosaurus Korner, 91 Goldring St, Richmond, Queensland 4822, Australia. *Also affiliated with: Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia.

A methodology of theropod print replication utilising the pedal reconstruction of Australovenator and a simulated paleo-sediment

Distinguishing the difference between theropod and ornithopod footprints has proved a difficult task due to their similarities. Herein our aim was to produce a method where a skeleton could be more closely matched to actual fossilised footprints. The reconstructed pes of the Australian Megaraptoran Australovenator wintonensis was utilised for this footprint reconstruction. It was 3-D printed in life size, molded and cast to produce a flexible theropod foot for footprint creation. The Dinosaur Stampede National Monument, Lark Quarry, Queensland, Australia was used as our case study to compare fossilised dinosaur footprints with our reconstructed theropod prints. The footprints were created in a sediment that resembled the paleo-sediments of Lark Quarry prior to being traversed by dinosaurs. Measurements of our Australovenator prints with two distinctly different print types at Lark Quarry revealed similarities with one distinct trackway which has been the center of recent debate. These footprints consist of 11 consecutive footprints and show distinct similarities in both size and proportions to our Australovenator footprints.

Septate gastropods from the Upper Devonian of the Canning Basin: implications for palaeoecology

Cook, A.G., Jell, P.A., Webb, G.E., Johnson, M.E. & Baarli, B.G., 21.4.2015. Septate gastropods from the Upper Devonian of the Canning Basin: implications for palaeoecology. Alcheringa 39, 519–524. ISSN 0311-5518 Septate murchisoniid gastropods are documented from the Upper Devonian (Frasnian) Pillara Limestone, Canning Basin, Western Australia. Two localities were investigated corresponding to a peri-island and back reef setting. Extensive septation is reviewed for Palaeozoic gastropods and is interpreted to be an adaptation to shallow water, apical breakage in non-euomphaloidean gastropods, or combined with the possible need to adjust calcium levels in the mantle. Fletcherviewia from the Middle Devonian of north Queensland is reassigned to the Murchisoniidae. Alex G. Cook [alex.cook@y7mail.com], Peter A. Jell [p.jell@uq.edu.au] and Gregory E. Webb [g.webb@uq.edu.au], School of Earth Sciences, The University of Queensland, Queensland, 4072, Australia; Markes E. Johnson [mjohnson@williams.edu] and B. Gudveig Baarli [gbaarli@williams.edu], Department of Geosciences, Williams College, Williamstown, MA 01267, USA. Received 7.2.2015; revised 16.4.2015; accepted 21.4.2015.

Mecochirus Germar (Decapoda: Glypheoidea) in the Lower Cretaceous of Queensland

JELL, P.A., WOODS, J.T. & COOK, A.G., May 2017. Mecochirus Germar (Decapoda: Glypheoidea) in the Lower Cretaceous of Queensland. Alcheringa 41, 514–523 ISSN 0311-5518. Three new species of glypheoid decapod crustaceans, Mecochirus mcclymontorum, M. bartholomaii and M. lanceolatus, are described from the late Aptian of the Eromanga, Carpentaria and Maryborough basins, respectively. The first two occur in the Doncaster Member of the Wallumbilla Formation and the last in the Maryborough Formation. This is the first record of Mecochirus Germar, 1827 or the Mecochiridae Van Straelen, 1925 in Australia and one of only a few Cretaceous occurrences of this largely Jurassic genus. Peter A. Jell [amjell@bigpond.com], Jack T. Woods and Alex G. Cook [alex.cook@y7mail.com], School of Earth Sciences, The University of Queensland, St Lucia Queensland 4072, Australia.

Carboniferous platyceratid gastropods from Western Australia and a possible alternative lifestyle adaptation

Cook, A.G. & Jell, P.A., September 2015. Carboniferous platyceratid gastropods from Western Australia and a possible alternative lifestyle adaptation. Alcheringa 40, XX–XX. ISSN 0311-5518 Platyceratid gastropods, common and in many cases abundant as elements of middle Palaeozoic gastropod faunas worldwide, are rare or absent in Australian Devonian faunas. In Australia, the earliest abundant platyceratids occur in the Lower Carboniferous (Tournaisian) echinoderm-rich Septimus Limestone and Enga Sandstone in the Bonaparte Gulf Basin, Western Australia. Four taxa, each with significant morphological plasticity, are recognized. In Platyceras (Platyceras) tubulosus (de Koninck, 1883), three rows of long radially arranged spines and common pentameral symmetry of re-entrants on the aperture suggest an alternative possibility that a relationship between echinoderms and platyceratids developed, and that this may be with archaeocidaroids that are commonly preserved with the gastropods. Similarly in the singly spinose Platyceras (Platyceras) emmemmjae sp. nov., re-entrants suggest an echinoderm relationship. It is proposed that an echinoderm–Platyceras relationship possibly developed in Australia only after a suitable echinoid host had evolved allowing an alternative way for a gameto- or coprophagous habit to be exploited fully. Alex G Cook [alex.Cook@y7mail.com] and Peter A. Jell [p.jell@uq.edu.au], School of Earth Sciences, The University of Queensland, Queensland 4072, Australia.