Palaeontologists aim to resolve riddle of dinosaur playground

By Christina Sticht Sep 12, 2011, 16:59 GMT

Obernkirchen, Germany - He was more than three metres long, had feathers and was reminiscent of the relatively harmless emu. But this predator's razor-sharp, sickle-shaped claws presented a serious threat to considerably larger dinosaurs in his day.

The find in Germany of the tracks of the 1.4-metre-tall dinosaur from the Troodontidae family is the first of its kind in Europe. A highly realistic model of the dinosaur will soon be on show in the museum in Hanover, the capital of the state of Lower Saxony, where they were found some four years ago.

Torsten van der Lubbe has grown particularly fond of the birdlike creature. When weather allows he is on his knees in the sandstone quarries of Obernkirchen looking for tracks, which he then photographs using a special procedure that creates three-dimensional models.

'Three-dimensional photogrammetry is a landmark in trace research. Using it I am able to share information with experts all over the world,' Van der Lubbe says, wiping the sweat off his forehead. Behind him, quarrying machines rip blocks of stone out of the hillside.

The dinosaur team is working on a level area of around 400 square metres that is littered with traces of dinosaurs. Lubbe has counted 2,209 impressions made thus far. 'Huehnerhof' - or chicken yard - is now known internationally, says project leader Annette Richter, a palaeontologist at the Hanover state museum.

Leading dinosaur researchers from all over the world gathered in Obernkirchen in April and a book on the spectacular tracks is to be published by a renowned US scientific publisher.

The aim now is to find ways to explain why there are so many dinosaurs together at this spot. The frequency of predator dinosaurs - including Velociraptors and Allosaurus - is unusual.

Above the chicken yard there is a second plateau of around 2,000 square metres with hundreds of tracks. Here entire family groups of herbivorous dinosaurs waded through the mud moving from south to north.

The area was tidal mud flats during the Cretaceous period and possibly there was a fresh water source nearby, along with a favourite dinosaur nesting spot.

Laid out in Autumn 2010, a nature trail with nine stations along the way introduces visitors to the secrets of dinosaur tracks. Since the spring there have been regular guided tours to the upper plateau.

The chicken yard remains closed to visitors and accessible only to accredited researchers. 'It's as though we were trying to resolve a murder case dating 140 million years back,' Van der Lubbe says, justifying cordoning off the 'crime scene.'

Richter traces a finger over the impression of a herbivorous dinosaur measuring up to eight metres in height, the Iguanodon. The outlines of the toenails are discernible.

'This is reminiscent of the tracks of a real duck-billed dinosaur. But he could not yet have lived during the Cretaceous,' she says. Perhaps he came later and walked in the footsteps of his predecessor. 'Our American colleagues suggested this thesis and we're going to look into it,' Richter says.