Paleontologists have discovered a strange new species of bird-like dinosaur

A new theropod bird, 150 million years old, Fujianvenator is a miraclediscovered in China, provides new insights into the evolution of early and late birds Jurassic Terrestrial ecosystem.

Birds descended from theropod dinosaurs in the late Jurassic, but our earliest evolutionary understanding of Avialae, the clade that includes all modern birds but not Deinonychus or Troodon, hampered by the limited diversity of fossils from the Jurassic period. (A clade is a group of organisms consisting of a single common ancestor and all of its descendants, representing a single branch on the “tree of life.”)

To date, no specific birds have been reported except for the mid- and late Jurassic biogenic Yanliao birds of northeastern China (166-159 million years ago; Ma) and the slightly younger German Solnhofen Limestone, which preserves Archeopteryx. As a result, there is a gap of about 30 million years before the oldest known record of Earth Cretaceous period the birds. However, Jurassic birds are the key to deciphering the evolutionary origin of birds’ distinctive body plan. More importantly, it is key to reconciling the evolutionary debate about the origin of birds.

A photograph and interpretive line drawing of a 150-million-year-old theropod theropod. Fujianvenator is a miracle, with the breed and ancient map showing the location of the Zhenghe (red star) fauna. Credit: Min Wang

New discovery

A joint research team from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences in Beijing and the Fujian Institute of Geological Survey (FIGS) has described and analyzed a new 150-million-year-old bird theropod from Chenghe County. , Fujian Province.

The results were published in nature On September 6th.

the new Classifythe name of the thing Fujianvenator is a miracledisplays a curious set of shapes that are shared with other birds, troodontids, and dromeosaurids, illustrating the influence of evolutionary mosaicism in the evolution of early birds.

Morphometric space of the body’s plan and velocity Fujianvenator is a miracle, compared to other theropods of the Mesozoic. Credit: Min Wang

Unique Fujianvinator morphology

“Our comparative analyzes show that the observed changes in body plan occurred along the early, largely forelimb-driven flight line, ultimately giving rise to the typical avian limb ratio,” said Dr. Min Wang of IVPP, lead author and correspondent for the study. the study. “but, fujianventure It is an alien species that deviated from this main path and evolved strange hind limb architecture.

The surprisingly long lower leg and other shapes, as well as other geological observations, indicate this fujianventure It lived in a swamp-like environment and was a high-speed runner or long-legged wader, representing a previously unknown environment for early flying birds.

Stratigraphic record and assemblage of vertebrate fossils discovered in the Zhenghe fauna of the Late Jurassic. Credit: Min Wang

Geological context and archaeology

“next to fujianventureWe found many others vertebrates“Including teleosts, testudines and choristoderes,” said Liming Xu of FIGS, lead author of the study.

During the late Jurassic and early Cretaceous, southeastern China underwent intense tectonic activities due to subduction of the ancient Pacific plate, which resulted in widespread magma spreading and syn-rift depression basins, where fujianventure is found. This geological background is essentially the same as it was in the Late Jurassic of northern and northeastern China, where even older Yanliao biota are preserved.

“The exceptional diversity, unique composition of vertebrates, and paleoenvironment strongly suggest that this area documents a terrestrial fauna, which we have named Zhenghe Fauna,” said Dr. Zhonghe Zhou of IVPP, co-author of the study. Radioisotope dating and in situ stratigraphic surveys restrict the Chenghe fauna to a period of 150 to 148 million years ago. So, fujianventure Documents one of the smallest and most geographically recent members of the Jurassic flight in the extreme south.

The discovery of the Zhenghe fauna opens a new window on the planet’s Late Jurassic terrestrial ecosystem, and the joint research team from IVPP and FIGS plans to continue exploring Zhenghe and nearby areas.

Reference: “New avian theropods from the emerging Jurassic terrestrial fauna” by Liming Xu, Min Wang, Runsheng Chen, Liping Dong, Min Lin, Xing Chi Chang and Zhonghe Zhou, September 6, 2023, nature.
doi: 10.1038/s41586-023-06513-7