What is Archaeopteryx?

Archaeopteryx is a genus of feathered dinosaur dating back roughly 150 million years ago during the Late Jurassic Epoch. These fossils were discovered in Bavaria, Germany, starting in 1861. Once considered the oldest known fossil bird, later discoveries of similar bird-like fossils, such as Xiaotingia zhengi , have led some paleontologists to reclassify Archaeopteryx as a dinosaur. Archaeopteryx shared anatomical features with coelurosaurs (carnivorous dinosaurs). The presence of feathers on the first specimens suggested it was a bird. Unlike modern birds, it had well-developed teeth and a long tail with feathers on each side, and its three fingers bore claws and moved independently. Though it had wings, Archaeopteryx likely used bursts of powered flight over short distances.

When and where were Archaeopteryx fossils discovered?

Archaeopteryx fossils, once considered the oldest known bird fossils, date back roughly 150 million years to the Late Jurassic Epoch. The first Archaeopteryx fossil was discovered in 1861 in the Solnhofen Limestone Formation in Bavaria, Germany. The fine-grained limestone of this area allowed for exceptional preservation of fossil material, including feather impressions. Archaeopteryx shared many anatomical features with coelurosaurs (carnivorous dinosaurs); the presence of feathers on the fossils was a key identifier for classifying it as a bird.

Why is Archaeopteryx considered important in the study of evolution?

Archaeopteryx is significant in the study of evolution because it has features of both reptiles and birds, bridging the evolutionary gap between them. It had reptilian features such as teeth, a long tail, and unfused fingers with claws, but it also had avian features such as feathers and wings. Archaeopteryx , discovered in 1861, was once known as the earliest fossil bird. It provides insights into the evolution of flight, even though it may not have been able to sustain long-distance flight. The arrangement of melanosomes in its feathers suggests they provided structural support for bursts of flight, and skeletal structures indicate it evolved from small carnivorous dinosaurs.

What features does Archaeopteryx have that are similar to both birds and reptiles?

Archaeopteryx , once considered the oldest known fossil bird, exhibits a mix of avian and reptilian features. Bird-like features: * Possession of feathers * Wing structure and arrangement of wing feathers * Wishbone, breastbone, hollow thin-walled bones, air sacs in the backbones Reptilian features: * Well-developed teeth * Long, well-developed tail * Three fingers bearing claws that moved independently These shared characteristics have led some paleontologists to reclassify Archaeopteryx as a dinosaur.

How did Archaeopteryx help scientists understand the link between dinosaurs and birds?

Archaeopteryx , a feathered dinosaur from the Late Jurassic Epoch, has played a significant role in understanding the evolutionary link between dinosaurs and birds. The discovery of Archaeopteryx fossils, starting in 1861, revealed a mix of reptilian and avian characteristics. Though Archaeopteryx had well-developed wings and feathers similar to modern birds, it also shared many anatomical features with coelurosaurs (carnivorous dinosaurs). Unlike today's birds, Archaeopteryx had teeth, clawed fingers, and a long tail similar to those of smaller dinosaurs. These unique characteristics of Archaeopteryx helped scientists like Thomas Henry Huxley and John H. Ostrom establish that birds evolved from small carnivorous dinosaurs.

What have scientists learned about the environment and time period in which Archaeopteryx lived?

Archaeopteryx lived about 150 million years ago during the Late Jurassic Epoch. The Archaeopteryx fossils were discovered in the Solnhofen Limestone Formation in Bavaria, Germany. This limestone was formed in a shallow tropical marine environment, likely a coral lagoon, allowing exceptional fossil preservation. During the Jurassic period, the supercontinent Pangea split apart, creating the central Atlantic Ocean and the Gulf of Mexico. Increased plate tectonic movement caused volcanic activity and mountain-building. Warm-adapted plant fossils suggest an expanded tropical zone, with a smaller temperature difference between the Equator and the poles compared to today. Global temperatures were generally warm, with the warmest temperatures in the Late Jurassic.

Archaeopteryx

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Images, Videos & Interactives

Side-by-side illustration comparing a modern black-and-white bird on the left with a feathered dinosaur, Archaeopteryx, on the right, both with wings spread.

Dr. Jingmai O'Connor smiles and gestures toward a fossil of Archaeopteryx on display at the Field Museum, with exhibit text visible in the background.

Illustration of Archaeopteryx, a small feathered dinosaur from the Late Jurassic, showing bird-like wings with clawed fingers, sharp teeth, and a long feathered tail with a bony core. Measurement bars above indicate its length and wingspan of about 2 feet.

Diagram showing evolutionary relationships among archosaurs, dinosaurs, modern crocodiles, the small dinosaur Troodon, the ancestral bird Archaeopteryx, and a modern chicken, with arrows tracing lineage from archosaurs to both crocodiles and birds.

At a Glance

archaeopteryx summary

Quick Facts

Key People:: John Ostrom; Sir Gavin de Beer

Related Topics:: feathered dinosaur; theropod; Late Jurassic Epoch

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Archaeopteryx

fossil animal genus

Also known as: Archaeopteryx lithographica

Written and fact-checked by

Britannica Editors

Last updated

Nov. 13, 2026 •History

Top Questions

What is Archaeopteryx?
Archaeopteryx is a genus of feathered dinosaur dating back roughly 150 million years ago during the Late Jurassic Epoch. These fossils were discovered in Bavaria, Germany, starting in 1861.

Once considered the oldest known fossil bird, later discoveries of similar bird-like fossils, such as Xiaotingia zhengi, have led some paleontologists to reclassify Archaeopteryx as a dinosaur.

Archaeopteryx shared anatomical features with coelurosaurs (carnivorous dinosaurs). The presence of feathers on the first specimens suggested it was a bird. Unlike modern birds, it had well-developed teeth and a long tail with feathers on each side, and its three fingers bore claws and moved independently. Though it had wings, Archaeopteryx likely used bursts of powered flight over short distances.
2 Britannica Sources
1. Archaeopteryx
2. bird: Fossil birds
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
When and where were Archaeopteryx fossils discovered?
Archaeopteryx fossils, once considered the oldest known bird fossils, date back roughly 150 million years to the Late Jurassic Epoch. The first Archaeopteryx fossil was discovered in 1861 in the Solnhofen Limestone Formation in Bavaria, Germany. The fine-grained limestone of this area allowed for exceptional preservation of fossil material, including feather impressions. Archaeopteryx shared many anatomical features with coelurosaurs (carnivorous dinosaurs); the presence of feathers on the fossils was a key identifier for classifying it as a bird.
1 Britannica Source
1. Archaeopteryx
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Why is Archaeopteryx considered important in the study of evolution?
Archaeopteryx is significant in the study of evolution because it has features of both reptiles and birds, bridging the evolutionary gap between them. It had reptilian features such as teeth, a long tail, and unfused fingers with claws, but it also had avian features such as feathers and wings.

Archaeopteryx, discovered in 1861, was once known as the earliest fossil bird. It provides insights into the evolution of flight, even though it may not have been able to sustain long-distance flight. The arrangement of melanosomes in its feathers suggests they provided structural support for bursts of flight, and skeletal structures indicate it evolved from small carnivorous dinosaurs.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What features does Archaeopteryx have that are similar to both birds and reptiles?
Archaeopteryx, once considered the oldest known fossil bird, exhibits a mix of avian and reptilian features.

Bird-like features:
* Possession of feathers
* Wing structure and arrangement of wing feathers
* Wishbone, breastbone, hollow thin-walled bones, air sacs in the backbones

Reptilian features:
* Well-developed teeth
* Long, well-developed tail
* Three fingers bearing claws that moved independently

These shared characteristics have led some paleontologists to reclassify Archaeopteryx as a dinosaur.
2 Britannica Sources
1. Archaeopteryx
2. bird: Fossil birds
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How did Archaeopteryx help scientists understand the link between dinosaurs and birds?
Archaeopteryx, a feathered dinosaur from the Late Jurassic Epoch, has played a significant role in understanding the evolutionary link between dinosaurs and birds. The discovery of Archaeopteryx fossils, starting in 1861, revealed a mix of reptilian and avian characteristics.

Though Archaeopteryx had well-developed wings and feathers similar to modern birds, it also shared many anatomical features with coelurosaurs (carnivorous dinosaurs). Unlike today's birds, Archaeopteryx had teeth, clawed fingers, and a long tail similar to those of smaller dinosaurs.

These unique characteristics of Archaeopteryx helped scientists like Thomas Henry Huxley and John H. Ostrom establish that birds evolved from small carnivorous dinosaurs.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What have scientists learned about the environment and time period in which Archaeopteryx lived?
Archaeopteryx lived about 150 million years ago during the Late Jurassic Epoch. The Archaeopteryx fossils were discovered in the Solnhofen Limestone Formation in Bavaria, Germany. This limestone was formed in a shallow tropical marine environment, likely a coral lagoon, allowing exceptional fossil preservation.

During the Jurassic period, the supercontinent Pangea split apart, creating the central Atlantic Ocean and the Gulf of Mexico. Increased plate tectonic movement caused volcanic activity and mountain-building. Warm-adapted plant fossils suggest an expanded tropical zone, with a smaller temperature difference between the Equator and the poles compared to today. Global temperatures were generally warm, with the warmest temperatures in the Late Jurassic.
6 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Archaeopteryx, genus of feathered dinosaur considered by many authorities to be the earliest known fossil bird. The specimens date to approximately 150 million years ago, during the Late Jurassic Epoch (163.5 million to 145 million years ago), and all were found in the Solnhofen Limestone Formation in Bavaria, Germany, starting in 1861. However, late 20th- and early 21st-century discoveries of other birdlike fossils of similar age, including Xiaotingia zhengi from the Liaoning deposits in China, have prompted several paleontologists to call for the reclassification of Archaeopteryx as a dinosaur.

Physical characteristics

Much of what is known about Archaeopteryx comes from a series of well-preserved fossil specimens. The Solnhofen Limestone is a very fine-grained Jurassic limestone formed in a shallow tropical marine environment (probably a coral lagoon), where lime-rich muds slowly accumulated and permitted fossil material to be exceptionally well preserved. Several of the fossils show clear impressions of feathers. The sizes of the specimens range from that of a blue jay to that of a large chicken.

Archaeopteryx shared many anatomic characters with coelurosaurs, a group of theropods (carnivorous dinosaurs). In fact, only the identification of feathers on the first known specimens indicated that the animal was a bird. Unlike living birds, however, Archaeopteryx had well-developed teeth and a long well-developed tail similar to those of smaller dinosaurs, except that it had a row of feathers on each side. The three fingers bore claws and moved independently, unlike the fused fingers of living birds.

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Archaeopteryx had well-developed wings, and the structure and arrangement of its wing feathers—similar to that of most living birds—indicate that it could fly. However, evidence suggests that the animal’s powered flight differed from that of most modern birds. The bones of Archaeopteryx were strong enough to handle low torsional forces, which allowed for bursts of powered flight over short distances to elude predators, rather than high torsional forces, which are required for rapid flapping and soaring. A study of melanosomes (the pigmented, melanin-producing granules present in specialized skin cells called melanocytes) in the animal’s feathers revealed that the feathers were black and that the arrangement of the granules within the feather’s microstructure probably provided increased structural support to the wings, similar to the way it does in modern birds.

Skeletal structures related to flight are incompletely developed, however, which suggests that Archaeopteryx may not have been able to sustain flight for great distances. Archaeopteryx is known to have evolved from small carnivorous dinosaurs, as it retains many features such as teeth and a long tail. It also retains a wishbone, a breastbone, hollow thin-walled bones, air sacs in the backbones, and feathers, which are also found in the nonavian coelurosaurian relatives of birds. These structures, therefore, cannot be said to have evolved for the purpose of flight, because they were already present in dinosaurs before either birds or flight evolved.

Ongoing debate

Several paleontologists note that some birdlike dinosaurs of similar age or older also possessed features identical or nearly identical to those of Archaeopteryx. Many features, such as the presence of feathers, three-fingered hands, a wishbone, and long robust forelimbs, which are often considered diagnostic of birds, also appear in X. zhengi and Aurornis xui, species thought to have lived some 5 million and 10 million years before Archaeopteryx, respectively, as well as others. Thus, these paleontologists claim that Archaeopteryx cannot in fact be the world’s most primitive bird, and many of the features used to describe birds could be applied to the Paraves, a more inclusive collection of theropod dinosaurs that includes birds and the deinonychosaurs (a group that contains the troodontids and the dromaeosaurs).

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The Editors of Encyclopaedia Britannica This article was most recently revised and updated by John P. Rafferty.

Archaeopteryx

Physical characteristics

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Ongoing debate