This small prehistoric rarity found in northern Myanmar has over a hundred sharp teeth and reptilian eyes.
About 99 million years ago, a small dinosaur that preceded modern birds was trapped in a tree’s resin, eventually hardening into amber, preserving the specimen for posterity.
Its skull measures just 7.1mm in length, indicating that it was similar in size to the bee hummingbird, the smallest living bird in the world, weighing just 2 grams. According to the researchers, this new species could be the smallest Mesozoic dinosaur recorded to date.
The name with which you have been baptized, Oculudentavis Khaungraae, reflects its striking features. The skull, which shows a unique pattern of fusion between different bone elements, is dominated by a large lizard-like eye socket. The eye socket has a narrow opening and only lets in a small amount of light, indicating that the dinosaur had daytime habits.
Computed tomography scan of the ‘Oculudentavis khaungraae’.
And despite its tiny size, Oculudentavis He was not shy at all, as evidenced by his large number of sharp teeth, which suggest that he was a predator. It probably fed on small arthropods or invertebrates, unlike modern birds of similar size, which have no teeth and take nectar for sustenance.
Artist’s rendering of the ‘Oculudentavis khaungraae’, a predator with a hundred sharp teeth in its beak. Credit: Zhixin Han.
“It has more teeth than any other known Mesozoic (dinosaur age) bird,” said study co-author Jingmai O’Connor, a professor of paleontology at the Chinese Academy of Sciences. “He even has teeth on the back of his jaw, under his eyes, suggesting that the animal could open its really big mouth.”
Amazing discovery
The piece of amber where the specimen is found was excavated in a Myanmar (formerly Burma) mine in 2016, and purchased by Khaung Ra, who in turn donated it to his son-in-law’s museum, the Hupoge Amber Museum in China. Later, study researcher and co-author Lida Xing, an associate professor at the China University of Geosciences, taught the dinosaur bird scans to O’Connor and his colleagues to help identify it.
During the life of the small dinosaur, it flew between resin-producing trees that, at that time, grew on the edge of the brackish waters that surrounded the arc-shaped island that was Myanmar. A theory about the size of animals suggests that large creatures tend to “miniaturize” when they evolve in isolation on an island, as in this case.
Evolution of the first birds
As Roger Benson of the University of Oxford explains in an article accompanying the study published in the journal Nature, the new find illustrates how some of the earliest birds evolved from dinosaurs to become miniatures sooner than previously thought.
The size of Oculudentavis is a sixth of the smallest known early bird fossil.
“This indicates that, just shortly after their origins at the end of the Jurassic period (between 201 and 145 million years ago), birds had already reached their minimum body size. By contrast, the smallest dinosaurs weighed hundreds of times more. Understanding when, how, and why the lower body size limits changed in this way requires a greater understanding of early fossil birds and Oculudentavis it is a springboard for this ”, estimates the researcher.
The preservation of the specimen also indicates how Burmese amber is able to provide unprecedented information about the soft tissues and skeletal anatomy of small animals that do not preserve well in other sediments such as mud or sand due to their fragile nature. Delicate vertebrates, such as lizards and birds, have been found in amber formed from the resin of conifers.
As Benson says, “The potential for continuous discovery remains great, especially for animals of minute sizes.”
Source: Live Science. Edition: ABC.
