Avialae is a group of dinosaurs that includes all modern birds and their closest extinct relatives. This group represents the evolutionary branch where dinosaurs took to the skies and eventually became the feathered friends we see today.


Avialae began to evolve around 160 million years ago during the Jurassic period. These dinosaurs developed features that helped them fly, like lightweight bones, feathers, and wings. Over time, they became more and more bird-like, leading to the diverse group of flying animals we see today.

The word “Avialae” comes from Latin and means “bird wings.” This name reflects the key feature that sets this group apart from other dinosaurs – their ability to fly. However, not all members of Avialae could fly. Some early members may have only been able to glide, while others lost the ability to fly later in their evolution.


Think of a family tree for dinosaurs. If you follow the branch that leads to modern birds, you’d be tracing the history of Avialae. This branch includes famous prehistoric birds like Archaeopteryx, as well as all the birds we see today.

Fun Fact

Did you know that the smallest known dinosaur was a member of Avialae? Oculudentavis khaungraae, discovered in 2020, was about the size of a hummingbird! This tiny creature lived about 99 million years ago and shows just how diverse the Avialae group became.

People Also Ask

  • Are all birds part of Avialae?
  • When did Avialae first appear?
  • How are Avialae different from other dinosaurs?

Are all birds part of Avialae? Yes, all modern birds are part of Avialae. In fact, birds are the only living members of this group. All other Avialae went extinct along with the non-avian dinosaurs about 66 million years ago.

When did Avialae first appear? The first members of Avialae appeared during the Late Jurassic period, about 160-150 million years ago. The famous Archaeopteryx, often called the “first bird,” lived around this time and is one of the earliest known members of Avialae.

How are Avialae different from other dinosaurs? Avialae had several features that set them apart from other dinosaurs. They had feathers, which eventually developed into flight feathers. They also had lighter, hollow bones which made it easier to fly. Over time, many Avialae developed beaks instead of teeth, and their tails became shorter.