Posted on 10/07/2021 8:14:26 AM PDT by Red Badger
A Caudipteryx zoui fossil cast. (Daderot/Wikimedia Commons/CC0 1.0)
The remnants of DNA may lurk in 125 million-year-old dinosaur fossils found in China. If the microscopic structures are indeed DNA, they would be the oldest recorded preservation of chromosome material in a vertebrate fossil.
DNA is coiled inside chromosomes within a cell's nucleus. Researchers have reported possible cell nucleus structures in fossils of plants and algae dating back millions of years. Scientists have even suggested that a set of microfossils from 540 million years ago might hold preserved nuclei.
These claims are often controversial, because it can be hard to distinguish a fossilized nucleus from a random blob of mineralization created during the fossilization process.
DinosaurImpression Artist's reconstruction of Caudipteryx. (Zheng Qiuyang)
In the new study, published Sept. 24 in the journal Communications Biology, researchers compared fossilized cartilage from the feathered, peacock-size dinosaur Caudipteryx with cells from modern chickens; they found structures in the fossils that looked much like chromatin, or threads of DNA and protein.
"The fact that they are seeing this is really interesting, and it suggests we need to do more research as to what happens to DNA and chromosomes after cell death," said Emily Carlisle, a doctoral student who studies microscopic fossils and their preservation at the University of Bristol in England but was not involved in the new research.
Dino DNA? To answer the obvious burning question: No, we're nowhere close to resurrecting dinosaurs from their fossilized DNA.
"If there is any DNA or DNA-like molecule in there, it will be – as a scientific guess – very, very chemically modified and altered," Alida Bailleul, a paleobiologist at the Chinese Academy of Sciences who led the new research, wrote in an email to Live Science.
However, Bailleul said, if paleontologists can identify chromosome material in fossils, they may someday be able to unravel snippets of a genetic sequence. This could reveal a little more about dinosaur physiology.
But first, researchers have to find out if the DNA is even there. Until recently, most paleontologists thought that rot and decay destroyed the contents of cells before fossilization could take hold.
Any microscopic structures inside cells were considered collapsed cell contents, such as organelles and membranes, that had rotted before mineralization, Carlisle told Live Science.
More recently, though, paleontologists have found legitimate cell structures in a few fossils. For example, 190 million-year-old fern cells described in 2014 in the journal Science were buried in volcanic ash and fossilized so quickly that some were frozen in the process of cell division. Unmistakable chromosomes are visible in some of these cells.
In 2020, Bailleul and her colleagues reported the possible preservation of DNA in the skull of an infant Hypacrosaurus, a kind of duck-billed dinosaur that lived 75 million years ago, found in Montana.
The possible DNA was found in cartilage, the connective tissue that makes up the joints.
"We were specifically interested in the cartilage because it's a very good tissue for cellular preservation, perhaps even more so than bone," Bailleul said.
Hidden in stone For the new study, the researchers turned to a well-preserved specimen of Caudipteryx held by the Shandong Tianyu Museum of Nature in China.
Originally discovered in the northeastern province of Liaoning, the fossil has ample preserved cartilage, which the researchers stained with the same dyes used to image DNA in modern tissue. These dyes bind to DNA and turn it a specific color, depending on the dye, allowing the DNA to stand out against the rest of the nucleus.
Stone slab with fossil of caudipteryx, highlighting chromosome-like features (Zheng et al./Communications Biology/CC BY 4.0)
Above: A photo of the full slab holding the Caudipteryx fossil, with a close-up of the right femur (b), where scientists found the intriguing cells.
By examining the stained, fossilized cartilage with several microscopy methods, Bailleul and her team showed that the cartilage cells contain structures that look just like nuclei with a scramble of chromatin inside.
The stained dinosaur nuclei's resemblance to modern cells doesn't prove there is DNA inside them, though, Bailleul cautioned.
"What it means is that there are definitely parts of original organic molecules, perhaps some original DNA in there, but we don't know that yet for sure," she said. "We just need to go figure out exactly what these organic molecules are."
The imaging definitely seems to show nuclei, Carlisle said, but it's harder to identify fossilized chromosomes, because no one really knows what happens to chromosomes as they decay.
It's possible that the contents of the nucleus might just collapse into structures that look like chromosomes but are really just a jumble of meaningless mineralized junk; it's also possible that the fossilization process preserves some of the original molecular structure.
(One 2012 study suggests that DNA in bone will completely break down in about 7 million years, but the timing may depend heavily on environmental factors.)
"It would be really interesting to do more experiments into that, looking at what happens inside the nuclei instead of just what happens to it from the surface," Carlisle said.
Bailleul and her colleagues hope to collect more chemical data to nail down the identity of the mysterious structures.
"I hope we can reconstruct a sequence, someday, somehow," she said. "Let's see: I could be wrong, but I could also be right."
So, let’s grab a frog and go to work. I’d like to set a raptor family loose in Congress.
Can they actually “reconstruct/ breed” animals from DNA that old?
Only in Hollywood..........................
Heh.
A raptor family loosed in Congress would be a cruel death..............for the a raptor family............................
That’s because we’ve been lied about how old they really are.
There’s no way in hell those bones are “millions of years old”.
Refer to the Nodosaur specimen they found almost completely intact with cartilage and skin recently found in Canada I believe.
How possible is it for DNA to survive millions of years?
Unfortunately real velociraptors were about the size of chickens. A couple of allosaurs would be nice though.
Raptors would not stand a chance against the fossilized dinosaurs currently serving in congress.
Unfortunately real velociraptors were about the size of chickens.
—
Wiki:
“Velociraptor was a mid-sized dromaeosaurid, with adults measuring up to 2.07 m (6 ft 9 + 1 ⁄ 2 in) long, 0.5 m (1 ft 7 + 1 ⁄ 2 in) high at the hip, and weighing up to 15 kg (33 lb), though there is a higher estimate of 19.7 kg (43 + 1 ⁄ 2 lb). The skull, which grew up to 25 cm (10 in) long, was uniquely up-curved, concave on the upper surface and convex on the lower.”
Big Chickens.
Me too! I GUESS that about covers it...
Ok then, find some velociraptor DNA and make us an army of Raptors and let them loose in all the blue cities. Sounds like a plan to me.
And was just discovered in COVID vaxxines, along with a lot of other junk.
Bring back Dire Wolves!
Bring back Dire Straits!................................
“If there is any DNA or DNA-like molecule in there, it will be – as a scientific guess – very, very chemically modified and altered,”
What is the definition of fossilization?
Fossilization takes place either (i) by the complexation of mineral ions to functional groups in the organic material, gradually replacing the organic structure and, at the same time, trapping the degrading organic molecules in the polymerizing mineral matrix, or (ii) when amorphous minerals formed in the aqueous phase bind to the cell envelope (Konhauser et al., 2003;
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/fossilization
The Maryland “science guy” would take us out on school field trips a couple times a year.
We were marching through one of the limestone block tunnels built for the C&O Canal in the 1830s, when he stopped, shined his flashlight up at the ceiling of the tunnel and dramatically intoned “Look at those stalactites. They took millions of years to form”.
And from the back of the group, my 10 year old self said “Seriously??”
And strait jackets!!
Even “scientists” don’t comprehend what can happen in 1 million years.
The claims are absurd!
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