But some paleontologists aren’t convinced the preserved structures are respiratory organs
12:13PM, OCTOBER 19, 2018
ALBUQUERQUE — Fossilized lungs found preserved along with an ancient bird may breathe new life into studies of early avian respiration. If confirmed as lungs, the find marks the first time that researchers have spotted the respiratory organs in a bird fossil.
Scientists have previously described four fossils of Archaeorhynchus spathula, an early beaked and feathered bird that lived about 120 million years ago. But unlike those discoveries, a newly described fifth specimen contains significant traces of plumage, and, even more startling, the probable remnants of a pair of lungs, researchers say.
Vertebrate paleontologist Jingmai O’Connor and colleagues reported the findings October 18 at the Society for Vertebrate Paleontology’s annual meeting. The results were also published online October 18 in the Proceedings of the National Academy of Sciences.
About the size of a thrush, Archaeorhynchus was among the earliest ornithuromorphs, the lineage that led to modern birds. It was probably an herbivore, as all known fossils of the creature contain preserved gastroliths, or gizzard stones which some animals use to help grind food, in the belly. The new fossil was found in northeastern China and is part of the Jehol Biota. That wealth of well-preserved fossils dates to between 133 million and 120 million years ago and includes numerous feathered dinosaurs as well as birds.