Showing posts with label x-ray. Show all posts
Showing posts with label x-ray. Show all posts

Tuesday, June 23, 2015

Embryos Hatched After 200 Million Years

Dinosaur Eggs Ready To Hatch Secrets 200 Million Years Later


In the late winter of 1976, the world famous fossil collector James Kitching was doing a survey near South Africa’s border with Lesotho.

To his surprise he found a tiny clutch of six fossilized eggs along the side of the road at a place known as Rooidraai.
It took five years for skilled palentologists to remove enough rock matrix from the eggs so that they could be preliminarily identified as the first dinosaur embryos from South Africa and the oldest dinosaur embryos in the world.

Research on dinosaurs has truly blossomed in the 40 years since Kitching’s extraordinary find and a great deal more is now known about the baby dinosaurs in the eggs. But the exceptional secrets they hold are only now being fully uncovered because of developments in technology. This month the eggs were flown to Grenoble, a city at the foot of the French Alps, where they are being examined under a powerful CT scan at the European Synchrotron Radiation Facility.
The secrets of the embryonic dinosaurs whose parents roamed South Africa 200 million years ago are in the process of being hatched.

These high-resolution, 3D x-ray imaging methods are burgeoning in palaeontology. With advances in modern imaging methods we are now able to digitally remove rock matrix while making 3D models of the bones inside.

CT scans come to the rescue

The solution to all of these problems lies in CT scanning the specimen. The x-ray resolution needed to study the embryos is so high (six microns, or .006 mm) that only a few facilities in the world are capable of performing the study.

In late 2014, a team of us put together a winning proposal to scan the eggs at the European Synchrotron Radiation Facility in Grenoble. At the facility, a huge ring of electrons (almost a kilometre in circumference) traveling at .99% of the speed of light continuously generates beams of high-energy X-rays. These beams can be harnessed with great precision to peer through rocks and image the fossils inside.
Full story here

Wednesday, December 10, 2014

Secrets of Dinosaur Footprints Revealed in Bird X-Rays


A detailed X-ray video of a modern bird foot is revealing the secrets of dinosaur tracks set down more than 250 million years ago.
The ancient tracks, made by the chicken-size dinosaur Corvipes lacertoideus, contain strange features that are likely the marks made when the dino withdrew its foot from the sediment — a process that is impossible to document without X-rays that reveal what's below the sediments.
The new video "is the first time anyone has been able to see a footprint being formed," said study author Peter Falkingham, a research fellow at the University of London's Royal Veterinary College. [See X-ray Video of Footprint Formation]
Falkingham and his colleagues used X-rays to videotape a bird called a guineafowl (a relative of chickens and pheasants) as it walked through a soft bed of poppy seeds. The researchers could see the foot plunging into the seeds, just as a dinosaur foot might have sunk into soft sand or dirt.
Frozen motion
Dinosaur prints are the only direct record of dinosaur movement, Falkingham told Live Science. But they are very tricky to interpret. A fossil print might come from the original land surface where the dinosaur stepped, or it might be an impression left over from several rock layers down, after the surface layer eroded away.
Prints are static impressions, Falkingham said, but a moving dinosaur foot is dynamic. Unlike celebrities carefully pressing their handprints into the cement on the Hollywood Walk of Fame, a walking dino didn't create an anatomically correct impression in the ancient soil. The dinos sank down, swept their toes through the dirt and flexed their foot muscles as they moved. Without an understanding of this process, scientists can only glean so much from dinosaur tracks.
Falkingham and his colleagues wanted to peer below the surface, second by second, as a track was being made. They chose guineafowl as their subjects because the birds are close in size to the dinosaur print fossils that the researchers wanted to use as comparisons. And, as birds, guineafowl are descendents of the avian dinosaurs.
"They are small dinosaurs without a tail, and that makes them a fantastic correlate for looking at the footprints produced by dinosaurs and produced by birds," Falkingham said.
In an X-ray machine, the birds trotted over solid surfaces and through dry poppy seeds, an analogue for sand or other soft sediment. Next, the researchers used computer simulations to model the movement of every single little poppy seed as the bird strode through. 

Link to full article