Life reconstruction of the 150-million-year-old avialan theropod Fujianvenator prodigiosus. Credit: Chuang Zhao
A brand new 150-million-year-old avialan theropod, Fujianvenator prodigiosus, has been found in China, providing contemporary insights into early hen evolution and the Late Jurassic terrestrial ecosystem.
As of now, no definitive avialans have been reported besides the Middle–Late Jurassic Yanliao Biota in northeast China (166–159 million years in the past; Ma) and the marginally younger German Solnhofen Limestones, which protect Archaeopteryx. Consequently, there’s a hole of about 30 million years earlier than the oldest identified report of Cretaceous birds. However, the Jurassic avialans are key to deciphering the evolutionary origin of the attribute avialan physique plan. More importantly, they’re key to reconciling the phylogenetic controversy in regards to the origin of birds.
Photograph and interpretive line drawing of the 150-million-year-old avialan theropod Fujianvenator prodigiosus, with a phylogeny and paleomap displaying the locality of the Zhenghe Fauna (purple star). Credit: Min Wang
A New Discovery
The findings have been revealed in Nature on September 6.
The new species, named Fujianvenator prodigiosus, displays a weird meeting of morphologies which are shared with different avialans, troodontids, and dromaeosaurids, displaying the affect of evolutionary mosaicism in early hen evolution.
Morphometric house of physique plan and cursoriality of Fujianvenator prodigiosus, in contrast with different Mesozoic theropods. Credit: Min Wang
Fujianvenator’s Unique Morphology
“Our comparative analyses show that marked changes in body plan occurred along the early avialan line, which is largely driven by the forelimb, eventually giving rise to the typical bird limb proportion,” stated Dr. Min Wang from IVPP, lead and corresponding writer of the examine. “However, Fujianvenator is an odd species that diverged from this main trajectory and evolved bizarre hindlimb architecture.”
The surprisingly elongated decrease leg and different morphologies, together with different geological observations, counsel that Fujianvenator lived in a swamp-like atmosphere and was a high-speed runner or a long-legged wader, representing a beforehand unknown ecology for early avialans.
Stratigraphic log and vertebrate fossil assemblage found within the Late Jurassic Zhenghe Fauna. Credit: Min Wang
Geological Context and Implications
“Besides Fujianvenator, we have found abundant other vertebrates, including teleosts, testudines, and choristoderes,” stated Liming Xu from FIGS, lead writer of the examine.
During the Late Jurassic–Early Cretaceous, southeastern China underwent intensive tectonic actions as a consequence of subduction of the paleo-Pacific plate, leading to widespread magmatism and coeval fault-depression basins, the place Fujianvenator was discovered. This geological background is basically the identical as within the Late Jurassic in north and northeastern China, the place the older Yanliao Biota is preserved.
“The extraordinary diversity, unique vertebrate composition, and paleoenvironment strongly indicate that this locality documents a terrestrial fauna, which we named the Zhenghe Fauna,” stated Dr. Zhonghe Zhou from IVPP, co-author of the examine. In-situ radioisotopic relationship and stratigraphic surveys constrain the Zhenghe Fauna to the interval from 150–148 Ma. Therefore, Fujianvenator paperwork one of many stratigraphically youngest and geographically southernmost members of the Jurassic avialans.
The discovery of the Zhenghe Fauna opens a brand new window into the Late Jurassic terrestrial ecosystem of the planet, and the joint analysis staff from IVPP and FIGS plan to proceed their exploration of Zhenghe and close by areas.
Reference: “A new avialan theropod from an emerging Jurassic terrestrial fauna” by Liming Xu, Min Wang, Runsheng Chen, Liping Dong, Min Lin, Xing Xu, Jianrong Tang, Hailu You, Guowu Zhou, Linchang Wang, Wenxing He, Yujuan Li, Chi Zhang and Zhonghe Zhou, 6 September 2023, Nature.
DOI: 10.1038/s41586-023-06513-7
