Scientists have discovered the fossilized remains of a baby bird in a 99-million-year-old piece of amber.
The little bird belonged to the enantiornithes, a major bird group from the time of the dinosaurs. Enantiornithes perished alongside dinosaurs in the extinction event 65 million years ago. The hatchling in question, however, likely died when a blob of tree resin fell on it. It had been just about a few days or weeks old when it died.
Half of the little bird's body remains in a good state in the amber. The remains include the bird's head, neck, part of one of its wings, a hind leg, and a foot. The specimen is all of three inches long, but it has given scientists the opportunity to understand what enantiornithes were like and how they compare to modern birds.
Though the fossil includes only half of the hatchling's body, it is still the most complete fossil in Burmese amber ever found.
Analysis of the fossilized remains revealed quite a lot of information on the hatchling and its species. The molting pattern on the baby bird revealed that it had just indeed been a baby when it died. Its feathers, which were still intact and visible, were brown, white, and dark gray.
Scientists also discovered that the hatchling already had all of its flight feathers, though plumage on other parts of its body had yet to come in. This suggests that young enantiornithes had the ability to fly upon hatching. Thus, they were likely less dependent on their parents at a young age than modern birds are.
However, it seems that the independence of enantiornithes hatchlings isn't necessarily an advantage. Enantiornithes had a slow growth rate, which meant that they were vulnerable to harm for a longer period of time. In fact, researchers noted that there were many fossils from the Cretaceous that contained the remains of enantiornithes hatchlings.
Researchers also noticed that the wing structure of enantiornithes was similar to that of modern flying birds. However, enantiornithes also had some features similar to those of theropods, the ancestors of modern birds.
Another thing that researchers noticed is that the hatchling appeared to be hunting when it died. Its posture, preserved in amber, was quite telling. It had opened its beak and claws and spread its wings, which looks to be an attack position. It didn't seem like the bird had been in distress or had been struggling when it died.
Museum director Chen Guang, owner of the fossil, recounted that many people had thought that the creature in the amber had been a lizard. The hatchling's claw, which is the most visible feature through the layers of amber, looked somewhat like a lizard claw. However, Chen guessed that the creature in the amber was actually bird. He then brought the fossil to researchers at the China University of Geosciences for identification.
Researchers nicknamed the bird “Belone”, after the Burmese name for a particular bird species with coloring similar to the color of amber. The fossilized baby bird will be on display at the Shanghai Museum of Natural History from June 24 to the end of July.
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