Small enantiornithine bird fossils discovered in China

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.

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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

Source: www.sci.news

The pioneering toothless beak of the Cretaceous enantiornithine bird

Paleontologists have described a new species of enantiornithine bird with a toothless beak from the Chinese Jehor bird family. This discovery delayed the earliest appearance of edentulism (lack of teeth) in enantiornithines by about 48 million years.

fossil skeleton of Impalavis Attenborough and bird restoration. Image credit: Ville Sinkkkonen / Wang other., doi: 10.1016/j.cretres.2024.105867.

Impalavis Attenborough They lived in what is now northeastern China about 120 million years ago (early Cretaceous period).

This bird was a member of a group called. enantiornis, or “the opposite bird.” It is named for the feature of its shoulder joint that is “opposite” to that found in modern birds.

Enantiornithines were once the most diverse group of birds, but became extinct 66 million years ago following a meteorite impact that wiped out most dinosaurs.

Paleontologists are still working to understand why enantiornithids went extinct and the birds that gave rise to modern birds survived.

“The enantiornithines are very strange. Most of them had teeth and still had clawed fingers,” said Dr. Alex Clark. student at the University of Chicago and the Field Museum.

“If you were to travel back in time to northeast China 120 million years ago and walk around, you might have seen something that looked like a robin or a cardinal. But it had an open mouth and a bunch of teeth. . When you lift your wings, you’ll notice that you have little fingers.”

“Scientists previously thought that the first record of this group without teeth was from the late Cretaceous period, about 72 million years ago.”

“This little man is Impalavis Attenborough, pushing it back about 48 to 50 million years. Therefore, the lack of teeth, or edentulism, developed much earlier in this group than we thought. “

fossilized skeleton Impalavis Attenborough It was discovered by an amateur fossil collector near the village of Toudaoyingzi in northeastern China and donated to the Tianyu Natural Museum in Shandong Province.

“I think what attracted me to this specimen was the forelimbs, not the lack of teeth,” said Dr. Jingmai O’Connor, associate curator of fossil reptiles at the Field Museum.

“It had a huge bicrest, and a bony protrusion on top of the upper arm bone that had muscles attached to it.”

“I had seen such emblems on birds from the Late Cretaceous period, but never in the Early Cretaceous period like this one. That’s when I first suspected that it might be a new species. It was.”

rare wing bones Impalavis Attenborough Muscle attachments that allowed this bird to flap its wings with extra force may have been possible.

“We’re looking at potentially very strong wingbeats,” Clark said.

“Some of the bone features are similar to those of modern birds such as puffins and murres, which can flap their wings at crazy speeds, or of birds such as quail and pheasants. Although they are small birds, they generate enough force to instantly fly almost vertically when threatened.”

On the other hand, a toothless beak Impalavis Attenborough Modern toothless birds have a wide variety of diets, so researchers aren’t necessarily sure what they ate.

Like its fellow enantiornithines, and unlike modern birds, it does not appear to have a digestive system called a gizzard or gastric mill to help grind up its food.

“Although most enantiornithines appear to have been quite arboreal, differences in forelimb structure suggest that Impalavis Attenborough Although it probably still lived in trees, it probably went down to the ground to feed, and it had a unique diet compared to other enantiornithines. This suggests that there is a possibility, and that it may also explain why they lost their teeth.” said Dr. said Connor.

In their study, the scientists also reexamined previously known bird fossils. Chiapiavisand suggests that it was also an early toothless enantiornithine.

“This discovery… Impalavis Attenborough “We show that the lack of teeth may not have been as unique in early Cretaceous enantiornithines as previously thought,” the researchers said.

The specific name is Impalavis Attenborough Attenborough’s strange bird, after the naturalist Sir David Attenborough.

Sir David Attenborough said: “It is a great honor to have your name attached to a fossil, especially one as spectacular and important as this one.”

“It seems the history of birds is more complicated than we thought.”

“All birds are dinosaurs, but not all dinosaurs fall into the special type of dinosaur known as birds. All squares are rectangles, but not all rectangles are squares. Is the same.”

“The newly explained Impalavis Attenborough Since it’s a bird, it’s also a dinosaur.”

a paper description Impalavis Attenborough Published in an online journal Cretaceous research.

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Wang Xiaoli other. 2024. The first edentulous enantiornithines from the Early Cretaceous Jehol ornithians (Birds: Ornithorax). Cretaceous research 159: 105867; doi: 10.1016/j.cretres.2024.105867

Source: www.sci.news