It was a typical Japanese summer season — sizzling, humid and cloudy — when archaeologists pulled a well-preserved, fossilized chook from the bottom in 2013. Their discover, announced this week in Communications Biology, would possibly change our concept of what diversifications have been important to the event of flight.
Close to Flight
Named Fukuipteryx prima, the archaeologists date the chook to the Early Cretaceous, a period 145 million to 101 million years in the past throughout which the evolution of flight was simply taking off. This is the primary species of early chook from the period discovered outdoors of China. And though this specimen most likely couldn’t fly very far, the fossil comprises a bone that researchers beforehand thought solely developed later, as birds have been refining flight.
Future fossils from Japan and elsewhere may additionally assist rework our understanding of how birds mastered the skies. “It may be a good opportunity for us to think back to what we thought we knew about bird evolution and start looking for new data in the regions where fossil birds are not very known, including Japan,” writes research coauthor Takuya Imai, a paleontologist with Fukui Prefectural University, through e mail.
All trendy birds carry a definite bone referred to as a pygostyle, a triangle of fused spinal vertebrae proper on the base of the tail. The construction helps tail feathers, and researchers thought it appeared in tandem with the event of flight in dinosaurs-turned-birds. Other birds from the identical period as this discover — all present in China — lack a pygostyle. But F. prima has one.
The discover was distinctive in different methods, too. F. prima maintained its 3D type within the mud because it fossilized, one thing not normally seen. Imai says they’re unsure how — it might have fossilized shortly, and minerals filtered into the hole bones and saved them from getting crushed below the burden of the soil. By having extra of the chook’s authentic dimensions, the staff might run a CT scan and assemble its total physique regardless of missing a number of the bones.
Based on their reconstruction, the staff thinks this chook was getting ready to full-fledged flight. The armlike appendages are longer than the legs, indicating they have been used like wings, however the dinosaur doubtless lacked the strong chest bones wanted for true flight, Imai says. This chook doubtless glided or flapped quick distances. And, after all, there’s the the aviation-friendly pygostyle, one thing paleontologists assumed this preflight specimen wouldn’t have.
The discover signifies that this important bone could have developed for different causes within the chook lineage and solely turned useful for flight later in evolution, Imai says. But extra excavations outdoors of China are crucial to verify this principle.
“If we keep doing that, our understanding about the Early Cretaceous evolution of birds on a global scale may completely change from what we currently think,” Imai says.