Bird-like dinosaur from China – 09/08/2023 – Science

About 148 million to 150 million years ago, a strange bird-like dinosaur about the size of a pheasant, with long legs and arms built like wings, inhabited southeastern China, with intriguing anatomy suggesting that it was either a speedy runner or had a lifestyle similar to that of a modern wading bird.

Scientists said last Wednesday (6) that they discovered in Fujian province the fossil of a dinosaur from the Jurassic Period that they called fujianvenator prodigiosus –a creature that sheds light on a critical evolutionary phase in the origin of birds.

The question of whether the fujianvenatorwith its curious mix of skeletal features, should it be classified as a bird depends on how one defines a bird, according to study leader Min Wang, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences.

When asked for a word to describe the fujianvenatorWang responded, “I would say ‘bizarre.’ fujianvenator It is far from resembling any modern bird.”

A notable event in dinosaur evolution occurred when small feathered bipedal dinosaurs, from a lineage known as theropods, gave rise to birds in the late Jurassic, with the oldest known bird – the Archeopteryx– dated to around 150 million years ago in Germany.

O fujianvenator It is a member of a group called avialans, which includes all birds and their closest non-avian dinosaur relatives, Wang said. Despite their humble beginnings, birds survived the asteroid strike 66 million years ago that doomed their non-avian dinosaur comrades.

the fossil fujianvenatordiscovered last October, is quite complete, but without the skull and parts of the feet, which makes it difficult to interpret its diet and lifestyle.

The leg bone Fujianvenator, the tibia, was twice as long as the thigh bone, the femur. These dimensions are unique among theropods, the group that includes all carnivorous dinosaurs such as Tyrannosaurus and several others. He also had a long bony tail.

“The forelimb is usually built like a bird’s wing, but with three claws on the fingers, which modern birds don’t have. So you might call it a wing. It’s not possible to determine whether it could fly or not. Based on the characteristics of the skeleton, the fujianvenator I probably wasn’t very good at flying,” Wang said.

“The fossil itself does not preserve feathers. However, its closest relatives and almost all known avialan theropods have feathers, and these are widely distributed among dinosaurs. Therefore, it would not be surprising if the fujianvenator had feathers,” Wang added.

Based on the anatomy of their long legs, researchers have proposed two possible lifestyles: running quickly or wading in a marshy environment, much like modern cranes or herons.

“I would bet on the runner,” Wang said.

Scientists seek to better understand the origins of birds, as well as non-avian dinosaurs with bird-like characteristics.

“For me, the Fujianvenator represents yet another interesting piece of evidence showing the wide distribution of several bird-like dinosaurs that lived at about the same time and shared habitats with their descendants, the birds,” said paleontologist Zhonghe Zhou of the Institute of Vertebrate Paleontology and Paleoanthropology, co-author of the study published in the journal Nature.

The first chapters in the history of birds remain obscure due to the scarcity of fossils. After Archeopteryx –a raven-sized bird with teeth, a long bony tail and no beak, whose fossils were first found in the 19th century– there is a gap of approximately 20 million years before the next birds appear in the fossil record .

“One thing is certain. There is still a big gap between the oldest known bird and the second oldest known bird,” Zhou said.

Translated by Luiz Roberto M. Gonçalves