Archaeorhynchus spathula – Ancient organs rarely fossilize, paleontologists were stunned to find the incredibly well-preserved remains of a dying bird.
Archaeorhynchus spathula ]a bird that lived about 120 million years ago, because its fossil had exquisitely preserved feathers, including a unique pintail that is not seen in any other bird, but is common in birds nowadays.
A closer inspection, however revealed that the bird's lungs had fossilized, meaning the paleontologists had discovered the oldest "informative" fossilized lung on record (more on that later) and the oldest fossilized lung ever seen in a bird's fossil, said co-lead researcher Jingmai O 'Connor, a professor of vertebrate paleontology and paleoanthropology at the Chinese Academy of Sciences. [Tiny Dino: Reconstructing Microraptor̵
The fossil itself is from the early Cretaceous Jehol deposit formation in northeastern China, but O'Connor and its colleagues found at the Shandong Tianyu Museum of Nature, in Pingyi, where an avid fossil collector houses the thousands of bird fossils he purchased over the decades
This is the fifth described A. spathula specimen – a toothless, pigeon-sized bird – but it's by far the best preserved, O'Connor said.
the researchers said. This means that A. spathula had unidirectional airflow in its lung – the air that flowed into what was fresh and full of oxygen, unlike the air in mammals' lung, which is mixed with both new and previously breathed air, meaning it has a lower oxygen content.
"Lungs of birds are very different from our lungs and [had] much more complex structures," said P. Martin Sander, a paleontologist at the University of Bonn in Germany in an email. Which are preserved here. "
Living crocodilians also have lungs with unidirectional airflow, and paleontologists considered it to be ancestral in early feathered dinosaurs.
To get a better look at the suspension remains, "we went and extracted some samples, put them in the SEM [scanning electron microscope] and – boom – lung tissue, "O'Connor told Live Science. Because O'Connor specializes in skeletal (not organ) anatomy, she roped in John Maina, a professor of zoology at the University of Johannesburg in South Africa, who is an expert on the living birds.
"I was like If you do not think so, then none of us digging-in-the-paleontologists can argue with you, O'Connor said. Maina's Contribution to the Study.
An analysis of the tissue has been found to be incorporated into the resuscitated blood capillaries. "Avian flight is the most demanding form of locomotion, so you need a lot of oxygen for it," O'Connor said. [Photos: Dinosaur-Era Bird Sported Ribbon-Like Feathers]
It's possible that this unique structure was unique to Ornithuromorpha, a clade (group) of ancient birds that survived the extinction of more than 66 million years ago and includes today's living birds. [their] survival, "O'Connor said.
What's more, it appears that the fossilized lung is embedded in the bird's ribs, just as bird lungs are today. O'Connor said.
The tissue does not appear to be left over stomach contents, as they usually do preserve as black, carbonized organic matter, she noted. Moreover, the preserved tissue is paired, just like a modern lung. Which is (which is lobed) because of this, but this is not specimens. "
However, this specimen is not t the oldest lung on record. That honor goes to Spinolestes an early Cretaceous mammal that has been fossilized lung about 5 million years older than the newly analyzed bird. Spinolestes other than that of a muscular diaphragm. So, O'Connor is calling the A. spathula fossil "the first informative lung remains," because they shed light on bird evolution.
The lung findings are "cool stuff," because it shows "what the lung of an early bird looked like," Sander said , However, because it's so rare to see a fossilized organ, this is a lung, he said.
"We should apply various other techniques to confirm that the area in the fossil really is lung, "he said. "But I would not be surprised if its high iron content because of the development in blood."
The 78th Annual Society of Vertebrate Paleontology Meeting yesterday (Oct. 18). It is published in the journal the Proceedings of the National Academy of Sciences on Monday (Oct. 22).
Published on Live Science .