Anchiornis

Anchiornis was a crow-sized, feathered dinosaur that lived in prehistoric Asia. Curved claws may have helped it to climb trees.

It had wing feathers on its arms and back legs, and some experts consider it a four-winged dinosaur. But it probably didn’t use the back wings for much in the air.

Anchiornis had smaller wings than some other feathered dinosaurs that lived at a similar time, such as Archaeopteryx. As such, it may not have been capable of powered flight, also called true flight, which involved flapping wings. Instead, it may have simply glided from one spot to another.

The remains of lizard bones and fish scales have been found with Anchiornis fossils.

These remnants were found inside gastric pellets – lumps of hard-to-digest matter such as bones, feathers and claws. Many modern birds form these in their stomachs after eating and then throw them up later.

So far, Anchiornis is the earliest bird relative known to have made these pellets.

It’s unusual for scientists to be able to tell the colour of any part of a dinosaur.

Remarkably, some Anchiornis fossils are so well preserved that experts have been able to recover pigments from multiple places around the body.

In one study, researchers discovered that Anchiornis was mostly black and grey, with a crest of red-brown feathers on its head and brown speckles on its face.

Another team looked at pigments in a different Anchiornis specimen as a follow-up. They found that although this one was also black and grey all over, it didn’t seem to have the red-brown colours on its head.

There are a few different theories for the colour differences. Perhaps the red-brown parts just didn’t preserve properly in the second specimen. Or maybe there were colour differences between different types of Anchiornis.

The specimen used in the first colour study was also a bit smaller than the second one. So, perhaps one of the specimens was male and the other female. Modern birds often have colour differences like this.

Another idea is that younger Anchiornis may have had the red-brown colour and lost it as they grew older.

Anchiornis was a very close relative of early birds, but it wasn’t a bird itself.

Ever since the discovery of Anchiornis, scientists have debated where it should sit on the evolutionary tree.

Originally, people thought it was a direct ancestor of birds – perhaps the earliest bird known to science. But later studies have shown that it was more like a cousin to the bird family line.

Anchiornis lived at a time when dinosaurs were evolving into birds. It had many bird-like features, such as feathers and wings.

This makes Anchiornis an important part of the story of how birds came to be. It shows us that many traits we associate with birds were already developing in some dinosaurs before true birds appeared.