Washington, July 30 : A new research has challenged the finding that soft, pliable tissues had been recovered from dissolved dinosaur bones in 2005.
The finding, made by paleontologists 3 years back, would have substantially widened the known range of preserved biomolecules, if proven true.
The original research, published in Science magazine, claimed the discovery of blood vessels and what appeared to be entire cells inside fossil bone of a Tyrannosaurus rex. he scientists had dissolved the bone in acid, leaving behind the blood vessel- and cell-like structures.
But new research challenges that finding and suggests that the supposed recovered dinosaur tissue is in reality biofilm - or slime.
According to Thomas Kaye, an associate researcher at the Burke Museum of Natural History and Culture at the University of Washington, "You have to go where the science leads, and the science leads me to believe that this is bacterial biofilm."
The new research claims that what was really inside the T.rex bone was slimy biofilm created by bacteria that coated the voids once occupied by blood vessels and cells.
Kaye likens the phenomenon to what would happen if you left a pail of rainwater sitting in your backyard. After a couple of weeks, you would be able to feel the slime that had formed on the inner walls of the bucket.
"If you could dissolve the bucket away, you'd find soft, squishy material in the shape of the bucket, and that's the slime," said Kaye. "The same is true for dinosaur bones. If you dissolve away the bone, what's left is biofilm in the shape of vascular canals," he added.
In addition to the acid bath procedure used in the previous work, Kaye added examination by electron microscope before the bones were dissolved.
The researchers found that what previously had been identified as remnants of blood cells, because of the presence of iron, were actually structures called framboids, microscopic mineral spheres bearing iron.
The scientists also dissolved bone in acid, as had been done previously, and found the same soft tissue structures.
They conducted a comparison using infrared mass spectroscopy and determined the structures were more closely related to modern biofilm than modern collagen, extracellular proteins associated with bone.
Using an electron microscope, the researchers saw coatings on the vascular canal walls that contained gas bubbles, which they associated with the presence of methane-producing bacteria.
In addition, they examined what looked like tiny cracks within the vascular canals and found that they were actually small troughs, or channels.
Study at high magnification revealed the channels had rounded bottoms and bridged each other, indicating they were organically created, likely by bacteria moving in a very thick solution.
"From this evidence, we could determine that what had previously been reported as dinosaurian soft tissues were in fact biofilms, or slime," said Kaye.