Earliest Known Modern Bird Fossil or Found to Date

Recently, a paper published in the British journal *Nature* described a newly discovered bird fossil, which may represent the earliest known modern bird species to date, providing clues for understanding the diversification of birds. The fossil skull is 6670-6680 million years old and exhibits features similar to those seen in chickens and ducks today. This discovery indicates that modern birds appeared just before the Cretaceous-Paleogene extinction event, caused by the impact of a large asteroid or comet.

Due to the gaps in the fossil record, the early evolution of crown birds has remained unclear (crown birds include all extant birds and their descendants—whether extant or extinct). Notably, only one well-supported example and several fragmentary fossils with uncertain links to crown birds existed in the Mesozoic Era (approximately 2.5 million years—6600 million years ago). The newly discovered bird fossils in theastrichtian of Maastricht, Belgium, may help to fill this gap.

British Cambridge University researcher Daniel Field reported that the fossil was remarkably well preserved, including almost a complete three-dimensional skull, and simultaneously exhibited features of both landbird-like and waterfowl-like species, such as a beak similar to that of modern landbirds. It was named *Asteriornis*, derived from Asteria, the Greek goddess of the dawn, who later became the quail. The name reflects both the impending asteroid impact at the end of the Cretaceous and the close relationship of the species to birds.

Researchers estimate that this bird weighed less than 400 grams. This relatively small body size, combined with its origin from marine sediments, suggests that the species may have been a shorebird, supporting the hypothesis that much of the diversity of crown birds originated from shorebird-like ancestors.

Source: Tech Daily