April 1, 2008

‘Virtual Paleontology’ Uncovers New Evidence

Paleontologists' vision of the past is becoming remarkably clearer thanks to a revolutionary new "supercamera."

Located in Grenoble, France, the European Synchrotron Radiation Facility (ESRF) uses an intense light capable of piercing almost any material.

Synchrotron technology has benefitted the efforts of French paleontologists such as Paul Tafforeau and Malvina Lak at the University of Rennes who have used the camera to study 640 blocks of opaque amber from the Charentes region in south-western France, resulting in the finding of 356 fossil animals such as wasps, flies, ants and even spiders.

"Opaque amber hosts many still unknown aspects of the past life on our planet, and the use of third generation synchrotron sources will continue to play an important role in unveiling them", asserts Malvina Lak.

Amber has been a continuous source of fossil evidence. It accounts for up to 80 percent of the amber found in Cretaceous sites like those in Charentes. However without synchrotron, most of these organisms would have never been spotted. One of the discovered mites reaches only 0.8mm across. A fossil wasp is large by comparison at 4mm in length.

"The small size of the organisms is probably due to the fact that bigger animals would be able to escape from the resin before getting stuck, whereas little ones would be captured more easily," said Lak.

Additionally, the team of researchers has succeeded at determining the 3D structure of some elements found in the dark amber. For example, they have recreated fragments of feathers that they hope will provide crucial information about an intermediate stage of some dinosaurs' evolution into modern birds.

Although the team does "not exclude that these fragments could have originated from an early bird featuring primitive feathers, they consider it more probable that they actually belonged to a feathered dinosaur," said the authors.

"Micro-tomography is based on radiography but instead of a single picture, we are taking pictures during rotation of the sample," explains Dr Tafforeau. "For a complete rotation, we will take more than 1,000 radiographs - and from all these radiographs, we can reconstruct virtual slices; and after using a 3D processing tool, we 'extract' the specimen from the amber."

"In some ways it is better than having the real animal."

In the future, ESRF hopes to improve and offer a variety of avenues for "virtual palaeontology".

One upgrade will improve the width of the X-ray beam from 4cm to 25cm, which will drastically reduce the needed amount of time to scan fossils.


On the Net:

European Synchrotron Radiation Facility

University of Rennes

European X-ray laser project

Diamond Light Source

European Strategy Forum on Research Infrastructures