Sociology

A bird with a T. rex head may help reveal how dinosaurs became birds

A 120-million-year-old fossil bird found in China could offer some new clues about how landbound dinosaurs evolved into today’s flying birds. The dove-sized Cratonavis zhui sported a dinosaur-like head atop a body similar to those of today’s birds, researchers report in the January Nature Ecology & Evolution.

The flattened specimen came from the Jiufotang Formation, an ancient body of rock in northeastern China that is a hotbed for preserved feathered dinosaurs and archaic birds. CT scans revealed that Cratonavis had a skull that was nearly identical (albeit smaller) as those of theropod dinosaurs like Tyrannosaurus rex, paleontologist Li Zhiheng of the Chinese Academy of Sciences in Beijing and colleagues report. This means that Cratonavis still hadn’t evolved the mobile upper jaw found in modern birds (SN: 5/2/18).

A digital reconstruction from CT scans shows the flattened Cratonavis specimen.
Researchers used CT scans to digitally reconstruct the flattened Cratonavis specimen (shown). The scans revealed that the creature had a theropod’s head and a bird’s body.Wang Min

It’s among just a handful of specimens that belong to a recently identified group of intermediate birds known as the jinguofortisids, says Luis Chiappe, a paleontologist at the Natural History Museum of Los Angeles County who was not involved in the study. Its dino-bird mishmash “is not unexpected.” Most birds discovered from the Age of Dinosaurs exhibited more primitive, toothed heads than today’s birds, he says. But the new find “builds on our understanding of this primitive group of birds that are at the base of the tree of birds.”

Cratonavis also had an unusually elongated scapula and hallux, or backward-facing toe. Rarely seen in Cretaceous birds, enlarged shoulder blades might have compensated for the bird’s otherwise underwhelming flight mechanics, the researchers say. And that hefty big toe? It bucks the trend of shrinking metatarsals seen as birds continued to evolve. Cratonavis might have used this impressive digit to hunt like today’s birds of prey, Li’s team says.

Filling those shoes may have been too big of a job for Cratonavis, though. Given its size, Chiappe says, the dino-headed bird would have most likely been a petite hunter, taking down the likes of beetles, grasshoppers and the occasional lizard rather than terrorizing the skies.


Source link Recently, a reimagined creature known as ‘The Chick-Rex’ has been making rounds in the scientific community, due to its unique gene-edited adaption. It contains a beak and wings, making it look like a bird, but its head is that of a Tyrannosaurus Rex.

Created by a team of Japanese researchers, the Chick-Rex, scientifically known as GalpasorcerexYorkimaculatus, is a modified form of a Japanese quail which was gene-edited to have the head of a Tyrannosaurus Rex. The research team, from the University of Tokyo and Toho University, made use of Crispr-Cas9 technology to achieve such a result.

The purpose of the Chick-Rex is to gain insights into the process by which dinosaurs evolved into birds. By present day understanding, it is widely accepted that the ancestors of birds were dinosaurs, however this research could add an extra layer of detail which might be used to supplant the existing hypothesis.

The modification process used has also opened up possibilities to attain a broader understanding of how embryos develop, as the easily manipulable Japanese quail was used as the base organism. With this method, the researchers were able to control the development of cranial features by manipulating the expression of the Sonic hedgehog gene, or SHH. With the manipulation of this gene, the researchers were successful in creating a hybrid which express the characteristics of both a bird and a dinosaur, in terms of its facial features.

The research has thrown up a new set of questions as well, like if the direction of the morphological changes induced by manipulation of Shh can be reversible. There remains much to be discovered, especially considering the fact that Shh is also involved in the formation of other parts of the body.

In any case, the Chick-Rex can be considered one of the most interesting discoveries made in recent times, as it has helped us learn more about our evolutionary origination and the whole process of embryo development.

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