Thursday, 30 August 2012

A New Species Of Jurassic Pterosaur

Recently, I purchased an ammonite. While the fossil itself is not particularly well preserved, what makes it special is the locality from which it comes. It was recovered from the Solnhofen Plattenkalk. 150 million years ago, the region was a saltwater lagoon on the edge of the ancient Tethys Ocean. It was inhabited by all manner of creatures from giant armored fish to the first ever birds. I now own a small piece of that incredible place.

The perfectly preserved, 150 million year old
fossil of Bellubrunnus rothgaengeri
Another famous group of creatures from the region were the pterosaurs. Indeed the first ever fossils of those winged reptiles were recovered from the pale, fine grained sandstone at Solnhofen by quarrymen in the mid 1800s. Many different species have been discovered over the years, one of them just this week. Recently, a fossil of a small pterosaur was unearthed in the quarry and put on display in a local museum.

Hundreds past it until a group of professional palaeontologists had a look. One was reported to have said 'how lovely, another Rhamphorhynchus.' However, David Hone from the University of Bristol saw something rather different. What leaped out at him was the incredible, complete nature of the fossil.
It was not just another Rhamphorhynchus.

The clinching feature was the ends of the wing bones which, unlike all other pterosaurs, curved back on the rest of the wing. In the end, he named the new species Bellubrunnus rothgaengeri or 'Brunn beauty' on account of its complete and well preserved nature. Pterosaurs were, by nature, fragile creature with light, hollow bones and thin wing membranes. Bellubrunnus's size, just 14 centimeters from head to tail and a 20 centimeter wingspan, would have increased its delicate state.

An artist's impression of Bellubrunnus rothgaengeri
It was down to the highly anoxic waters and fine grained, mineral rich mud that the specimen was preserved quickly and perfectly. Even so it is a near miracle that 150 million years in the ground the hundreds of tonnes of sediment pressing down on the tiny bones did not cause the fossil to warp. The state of the specimen meant that reconstructing its lifestyle was also a fairly easy job.  The closest relative of Bellubrunnus was in fact Rhamphorhynchus which accounts for the initial mix up.

Pterosaurs of that group possessed tails which consisted of overlapping rods of bone, creating a stiff, inflexible structure which helped stabilize the creatures in flight. By contrast, this creature had a flexible tail combined with back turned wings which would have destabilized its flight, but allowed it to make sharp, darting turns and dive quickly. This suggests that it was a completely aerial predator, possibly hunting insects and other flying creatures.

The Solnhofen Plattenkalk will continue to throw up new species of incredible significance. From the first birds to giant armored fish, aerial predators and ammonites, the limestone quarry is of the utmost importance to science. While commercial quarrying activities are in decline, and may even cease in the next few years, palaeontologists will continue to split the ancient, 150 million year old rocks to uncover the next generation of marvels.