A new genus and species of enantiornithine bird in the family Bohaiornithidae has been identified from a nearly complete, articulated skeleton preserved with feather marks found in northeastern China.
holotype of Neobohyornis ramadongensis. Image credit: Shen others., doi: 10.1038/s41598-024-82869-8.
Enantiornis, or “opposite bird”, is named for the feature of the shoulder joint that is “opposite” to that seen in modern birds.
These birds had toothed and clawed wings and occupied a variety of ecological niches comparable to neonis.
Once the most diverse group of birds, they became extinct 66 million years ago due to a meteorite impact that wiped out most of the dinosaurs.
The newly identified enantiornithine species lived during the Cretaceous period, about 119 million years ago.
with scientific name Neobohyornis ramadongensisthis bird belonged to an early enantiornithine family called . Bohiornithidae.
“The most diverse bird group of the Mesozoic Era was the enantiornithids,” said field museum paleontologist Dr. Jinmai O'Connor and colleagues.
“More than 100 named genera have been described to date, and fossils referable to this group of primarily arboreal birds have been described from nearly every continent, making it the largest known Mesozoic bird species. It accounts for half of the animals.
“Although restricted to smaller body sizes during the Early Cretaceous, by the Late Cretaceous Enantiornis had achieved a considerable size range and occupied diverse ecological niches.”
“The most abundant enantiornithine fossils come from deposits recording the Early Cretaceous Jehol biota in northeastern China, and the known Mesozoic bird diversity (130 to 100 million years) 20 million years ago).
“Bohaiornithids are characterized by a unique robust tooth morphology,” the researchers added.
“The tooth is apically pinched, gently curved apically, and mesiodistally robust near the base.”
“The most rostral teeth are typically smaller in size compared to the rest of the dentition.”
“Like most enantiornithids, Bohaiornithids are arboreal, based on the morphology of the foot, with the toe phalanges extending distally within each digit, ending in a highly recurved ungulate. It is highly likely that
“But compared to other species, their claws were proportionately larger and more curved.”
“The largest member of the clade (bohaiornis) may have approached a similar size to the small extant ascites (200 g). ”
“The largest known bohaiornithid is 167% the size of the smallest specimen yet reported, an unnamed juvenile.”
fossilized skeleton Neobohyornis ramadongensis It was discovered in the Jiufutang Formation near Ramadong, Liaoning Province, China.
“The fossil preserves a ring of feather traces from the caudal margin of the nostril to the underside of the neck, the shoulder and pelvic area, the lower leg feathers, the remige, and a pair of rachis-dominated tail feathers. “,” the paleontologists said.
According to the researchers, Neobohyornis ramadongensis It is estimated to weigh around 50g.
“in contrast, Neobohyornis ramadongensisand all other Bohaiornithids are estimated to have weighed more than 100 g,” they said.
The discovery of Neobohyornis ramadongensis Therefore, the body size range and diversity of Bohaiornithidae increases significantly. ”
“This suggests greater ecological diversity, but no direct evidence exists for the diet or ecological niche of this clade at this time.”
Neobohyornis ramadongensis It also preserves new information about the plumage of Bohaiornithidae birds.
This fossil, along with another specimen, shows that the primary feathers of Bohyornithids were about twice as long as the humerus, had rounded wing edges, and, like most other Early Cretaceous enantiornithids, had broad wings. It shows that he had.
“The new specimen represents a new species that contributes to the considerable recognized diversity of enantiornithines in the Bohaiornithidae of the Jiufudang Formation, especially with regard to body size,” the scientists said.
“This specimen reflects the reduced pinky and big fingers that evolved within this lineage as it evolved more sophisticated flight abilities in parallel with other enantiornithid lineages such as Myrididae. It highlights skeletal adaptations such as the possibility of increased sacral vertebrae.”
“The new specimen preserves the most well-known feathers of the Bohaiornithids, and it is possible that this clade had widespread rachis-centered tail feathers, as well as lower leg feathers. It shows that it has a high sex and there were no feathers on the podium.”
of work appear in the diary scientific report.
_____
C. Shen others. 2024. A new small species of enantiornithine (Birds: Ornithorax) from the Jehor Formation of the Early Cretaceous period in northern China. science officer 14, 31363; doi: 10.1038/s41598-024-82869-8
