Introducing Archaeornithura meemannae, a newly discovered species that is now the oldest-known member of an evolutionary branch that includes all living birds.
Illustration: Zongda Zhang.
A.meemannae lived about 130 million years ago during the Early Cretaceous period. It’s now the earliest member of the Ornithuromorpha clade ever found, and its discovery is setting back the evolutionary origin of birds by at least six million years. What’s more, because the bird is so incredibly bird-like and with very few primitive features, the scientists who analyzed the two fossil samples say there should be even older examples buried away somewhere in the fossil record. The results of their analysis now appear in Nature Communications.
The beautifully preserved fossils show signs of the bird’s plumage (Wang et al./Nature Communications).
As reported in the BBC, the researchers found the fossils in the Sichakou Basin of northeastern China. This diminutive bird, which stood 15 cm tall, is thought to have had bare legs, which suggests it waded in the water. The size and shape of the bones means A.meemannae may have been capable of nimble flight.
As is well known, birds began to evolve from dinosaurs at the end of the Jurassic period some 150 million years ago. 20 million years later, at least two different clades of early birds co-existed: Ornithuromorpha, which gave rise to modern birds, and Enantiornithes, a now extinct clade of birds that boasted teeth and clawed wings. And if the advanced features of the newly discovered bird is of any indication, it was one of many different types of Ornithuromorpha around during the Late Cretaceous.
Check out the scientific study at Nature: “The oldest record of ornithuromorpha from the early cretaceous of China”.