O. Archaeopteryx fossil

Archaeopteryx lithographica, the most valuable fossil in the Museum. Around 147 million years old.

First bird?

Illustration of an archaeopteryx perching on a branch.

Archaeopteryx (say ark-ee-OPT-er-ix) is the earliest known bird and this is the first one ever found. It is the most valuable fossil in the Museum’s collection.

This is the type specimen of the species, the one to which all others are compared.

Mysterious discovery

Archaeopteryx lithographica [London specimen]

When the fossil was discovered in Germany in 1861, it caused a lot of confusion. No birds were known from so far back. Some people even thought it wasn’t a bird, but an angel.

Richard Owen, this Museum’s first superintendent, knew there was something extraordinary about it. Even he didn’t realise just how remarkable it was.

Dinosaur or bird?

Sketch of Archaeopteryx

Sketch by Joseph Dinkel from Owen’s paper on Archaeopteryx, 1863.

Archaeopteryx was not like modern birds. It had feathers like a bird, but teeth, claws and a bony tail like a dinosaur.

Owen was world-famous for identifying animals. He classified Archaeopteryx as a bird, rejecting a suggestion that it might be a link to reptiles.

Evidence for evolution

Illustration of stages of evolution: dinosaur, archaeopteryx, bird

Evolution from dinosaur to bird.

The curious fossil was discovered just a few years after Charles Darwin published his controversial theory of evolution.

Darwin’s strongest supporter, Thomas Henry Huxley, first suggested Archaeopteryx showed an evolutionary link between dinosaurs and birds in 1868. And so the half-bird half-dinosaur became central to the evolution debate. Until then, no intermediate forms between living animals and their supposed ancestors had been found.

Taking wing?

Artwork of archaeopteryx in flight

After scrutinising Archaeopteryx, scientists decided it was a bird – the earliest discovered.

We are still learning about bird evolution from this fossil. The shape and arrangement of the wing feathers show similar adaptations for flight to modern birds.

Museum scientist Angela Milner led an international team that found further evidence Archaeopteryx could fly by studying its brain.

Bird brain

Diagram comparing features of brains from a pigeon, alligator and Archaeopteryx.

Bird brains fit very tightly in the skull so an imprint is left on the inside of the bones.

Of the 10 Archaeopteryx specimens known to science, this is the only one whose brain imprint has been fully preserved. From it, scientists built a 3D reconstruction of the brain, which shows Archaeopteryx had the sight, balance and co-ordination necessary for flight.

On the tree of life

Illustration of a fuzzy raptor.

Flightless feathered dinosaur, fuzzy raptor (Sinornithosaurus), lived in China 124–122 million years ago.

Fossils found more recently in China also have feathers, but ones adapted for warmth and display, not flight.

They are definitely dinosaurs and the closest relatives to Archaeopteryx yet discovered, so they throw into question whether Archaeopteryx was a bird after all.

On balance, the evidence still places Archaeopteryx with the birds, but only new discoveries will clarify the evolution of the bird family tree.

Iconic specimen

Photograph of the original type specimen.

Original type specimen.

In 2011 this fossil was elevated as the type, the one all others are compared to. Before this, the official representative was a single fossil feather. Despite being discovered first, we can’t prove it belonged to Archaeopteryx.

This specimen’s complete skeleton and feathers provide a more reliable reference for research on early birds.

Around the Museum

From the Beginning gallery.

See where Archaeopteryx fits in the timeline of life in From the Beginning, in the Red Zone.