A first look at ‘The Briefcase Dinosaur’

In a recent blog post, I’d just picked up our little opalised dinosaur during a visit to Lightning Ridge. Eager to have a look, I took it back to my hotel room to examine inside the three tatty boxes labelled ‘The Briefcase Dinosaur’. What followed was a wondrous couple of hours sorting through numerous plastic bags and trying to find out what we had acquired two years earlier.

Most of the specimen consists of rounded lumps of hardened siltstone. Where these had been cracked open they revealed cross sections through various bones and some of these lumps had patches of opalised bone poking out of their surfaces. It’s really hard to tell at this point what bones are present, but I could make out what appear to be several vertebrae, ribs and a couple of long bones probably from the hind limbs. 

A few pieces that did not have matrix were packed into foam inside a hard case, which was the origin of current working name for this dinosaur. Some of these could be more readily identified as pieces of a femur, parts of both tibia and some isolated vertebrae. In fact, several pieces could be joined together to create an almost complete femur. Features preserved on this bone indicate that this was a hypsilophodont dinosaur, similar to other specimens already recovered from Lightning Ridge and similar-aged deposits elsewhere in Australia.

The preservation was variable in quality from some exquisitely preserved pieces through to others that had distorted through time and with poor surface detail. Mostly they were composed of common, colourless opal known as potch but occasionally there were small pockets preserved in the dazzling rainbow of colours from precious opal.

From what I can make out, it appears that we have the back end of this creature with parts of both legs preserved, the tail and lumbar region and a few ribs. No sign yet of the pelvis but that could be in there somewhere. And, sadly, no hint of anything further forward in the skeleton, the front limbs and the skull.

All up it was a thrilling if somewhat frustrating couple of hours! Thrilling to be searching through and finding pieces of this little creature that lived and died so long ago. Frustrating because so much remains hidden, trapped within the white siltstone matrix. 

So it’s off back to Adelaide to run these precious pieces through a CT Scanner and peer within! Eventually the matrix will have to be removed and only then will we see these bones in all their glory but, until then, we can bring in modern technology to help us to see what we have got!