Tiny bird-like skull found in amber.

Scientists recently discovered the skull of an extremely tiny, bird-like dinosaur that could be the smallest known species of the Mesozoic era—the period in which giant dinos like brachiosaurus, stegosaurus, and allosaurus evolved.

The specimen is preserved in a lump of 99-million-year-old amber from northern Myanmar and measures just 7.1 millimeters long, suggesting that the entire animal might have been even smaller than the bee hummingbird, which, at about 2.25 inches, is the smallest bird in existence. Very small fossils like this one are rarely found because layers of silt and rock usually destroy the delicate tissues. Amber preserves them intact.

Jingmai O’Connor, the paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing who discovered the skull within the amber, and her colleagues found that the jaws contained more than 100 teeth—implying that, despite its size, the creature was a predator, possibly feasting on insects. However, since its eye sockets face the side, it probably didn’t have binocular vision, which gives many other predators the depth perception needed to catch prey. The conical shape of the bones in those eye sockets indicates that the animal had rather small pupils and was likely active during the day. The findings were published in the journal Nature. Read the full story.