In 2020, the discovery of approximately 99 million-year-old fossil remains in amber in northern Myanmar led us to believe that it was a flying dinosaur the size of a hummingbird . However, the strange Oculudentavis khaungraae , as the species had been described, has puzzled scientists since its discovery.
The fossil consists solely of a rounded, bird-like skull with a thin, tapered snout and a large number of teeth in the mouth, along with a deep, conical lizard-like eye socket. The bird-like characteristics led scientists to identify the fossil as a miniature flying dinosaur, the smallest ever found. Now, a new team of scientists has revealed the discovery of a second amber fossil that looks so much like O. khangraae that it belongs to the same genus. And the new specimen, named O. naga, is composed of a partial skeleton, which includes the entire skull with visible scales and soft tissue, that is, including parts of the lower part of the body that clearly reveal that members of the genus Oculudentavis They weren’t birds, but lizards.
The remains of this specimen are better preserved than those of the previous study. And despite its optimal preservation, they discovered that O. naga was such an unusual specimen that it turned out to be quite a puzzle to figure out exactly what it was.
Deformed skulls
The researchers used CT scans to examine both samples . The Oculudentavis lizard features included scales, teeth attached directly to the jaw rather than in the sockets (like dinosaur teeth), and a particular skull bone unique to scamatos or scaled reptiles.
“The specimen left us all perplexed at first because if it was a lizard, it was very unusual,” said Arnau Bolet, from the Institut Català de Paleontologia Miquel Crusafont in Barcelona. “We conclude that both specimens are similar enough to belong to the same genus, Oculudentavis , but a number of differences suggest that they represent separate species.”
The experts also determined that the skulls of both species had been deformed during conservation. Oculudentavis khaungraae’s snout was compressed into a narrower profile, more like a beak, while O. naga’s brain box, the part of the skull that encloses the brain, was compressed. The distortions highlighted bird features on one skull and lizard features on the other, said Edward Stanley, director of the Laboratory of Digital Dissemination and Discovery at the Florida Museum of Natural History.
Thus, the two tiny fossils are not of the same species, but belong to the same genus of lizard, which lived approximately 100 million years ago in the same region of the world.
Researchers are not yet sure where exactly Oculudentavis is in the lizard family, but at least now they are pointing in the right direction. What is clear is that it is a really strange animal , unlike any other lizard we have today.
Referencia: A. Bolet et al. Unusual morphology in the mid-Cretaceous lizard Oculudentavis. Current Biology. Published online June 14, 2021. doi: 10.1016/j.cub.2021.05.040.
Z. Li et al. Is Oculudentavis a bird or even archosaur? bioRxiv.org. Posted online June 8, 2020. doi: 10.1101/2020.03.16.993949.
