Diluvicursor pickeringi – Turkey to Rhea-sized Herbivore from the Early Cretaceous

Analysis of the fossilised remains of a little Ornithopod have led to the establishment of a new species of dinosaur, one that roamed the Australian-Antarctic rift valley approximately 113 million years ago.  Described from an almost complete tail and a partial right hind limb including foot bones, the dinosaur has been named Diluvicursor pickeringi (pronounced di-loovy-cursor pickering-i).  The species name honours David Pickering, (formerly Museums Victoria’s Vertebrate Palaeontology Collections Manager), a scientist who played a key role in the study of Early Cretaceous vertebrate fossils from the Otway and Gippsland Basins of the Australian State of Victoria.  David sadly passed away following complications after a serious car accident whilst the fossil material was being prepared and studied.

An Illustration of a Pair of Diluvicursor pickeringi Feeding Near a Fast-flowing River

Diluvicursor pickeringi illustrated.

A pair of Diluvicursor dinosaurs feeding next to a fast running river in the Antarctica/Australia rift valley 113 million years ago.

Picture Credit: P. Trusler

A Fossil Discovery in 2005

The fossils of this dinosaur described as being about the size of a turkey or a rhea (estimated maximum total body length, including tail at around 2.3 metres), were found on five slabs of rock that form part of a deposit representing a log jam event created in a high-energy (fast-flowing) river.  Writing in the academic journal “Peer J”, the authors of the scientific paper state that this newly described herbivorous dinosaur will help to shed new light on the phylogenetic relationships and the diversity of Ornithopoda of the southern hemisphere.

Dr Matt Herne (University of Queensland) and the corresponding author for the paper explained the significance of the fossils, which were excavated from a sea platform near Cape Otway.

He stated:

“Diluvicursor shows for the first time that there were at least two distinct body-types among closely related Ornithopods , small, two-legged plant-eating dinosaurs in this part of Australia.  One called Leaellynasaura was lightly built with an extraordinarily long tail, while the other, Diluvicursor, was more solidly built, with a far shorter tail.”

The Holotype Fossil Material of Diluvicursor pickeringi

The holotype of Diluvicursor and a schematic drawing

The five blocks (B1 to B5) of the holotype fossil of Diluvicursor (NMV P221080) note scale bar 10 cm. A schematic diagram of the fossil material is shown below (scale bar 10 cm).

Picture Credit: Peer J

A Fast Running Dinosaur

Analysis of the leg bones suggest that Diluvicursor was a fast running dinosaur.  The corpse of this dinosaur, representing a juvenile animal, came to rest mixed up with other debris deposited by a fast-flowing river.  The genus name reflects these two conclusions, Diluvicursor translates as “flood runner”.

The Proposed Body Shape of Diluvicursor with the Known Fossil Bones in Skeletal Position

Diluvicursor illustration showing known bones (scale bar = 10 cm).

Diluvicursor schematic restoration in left lateral view, showing preserved bones (light shading) and incomplete caudal vertebrae (outlined).

Picture Credit: Peer J

Volunteer prospector George Caspar discovered the fossil material in 2005 whilst exploring a coastal shore platform which forms part of the Eumeralla Formation of south-eastern Australia.   It is likely the carcass became trapped and buried along with flood-transported tree stumps, logs and branches in deep scours at the base of what was once a powerful river.

Dr Herne added:

“The Diluvicursor skeleton was discovered in 2005, but it’s taken this long to fully understand the geology of the area where it was found, and also Diluvicursor’s relationships.  Much of the fossil vertebrate material from this site has yet to be described, so we hope to discover further dinosaur species, specimens and other exciting animals there.”

An Injured Foot

A close examination of the right foot of the Diluvicursor specimen suggest that this dinosaur may have injured its foot some time before it perished.  Some of the bones are not aligned correctly and although this could be as a result of taphonomy, preserved roughened bone surfaces, suggest some form of trauma or disease.  The scientists conclude that the affected joint in the foot could have been immobilised.  The researchers are hopeful that further examination including a scan of the foot using synchrotron radiation X-rays will produce more data.

The Pathology on the Right Foot of the Diluvicursor Specimen

Diluvicursor pathology of the right foot.

A close up view of the second toe. Dotted line in B indicates rugose bone on the proximal margin of pedal digit IV-1. Dashed arrows in A–B indicate areas of osteophytosis (bone spurs around the damaged joint).

Picture Credit: Peer J

There are plans to display the post cranial fossil material at Melbourne Museum and the aim is to build up a much more complete picture of the palaeoenvironment of this part of Gondwana during the Albian faunal stage of the Cretaceous.  Other scientists involved in this study include Dr Steven Salisbury, PhD student Jay Nair and Dr Vera Weisbecker (University of Queensland), along with colleagues from Monash University.

The scientific paper: “A New Small-bodied Ornithopod (Dinosauria, Ornithischia) from a Deep, High-energy Early Cretaceous River of the Australian–Antarctic Rift System” by Matthew C. Herne​, Alan M. Tait, Vera Weisbecker, Michael Hall, Jay P. Nair, Michael Cleeland and Steven W. Salisbury published in Peer J.

Everything Dinosaur acknowledges the help of the University of Queensland in the compilation of this article.

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