| Name | Anchiornis | Diet | Carniivorous |
| Name Meaning | “Nearby bird” | Height | 20 centimeters (7.9 inches) |
| Pronunciation | An-chee-or-niss | Length | 60–62 centimeters (23.6–24.4 inches) |
| Era | Mesozoic– Late Jurassic | Weight | 0.6-1 kilogram (1.3-2.2 pounds) |
| Classification | Dinosauria, Saurischia, Sauropoda | Location | Liaoning, China |
Anchiornis Pictures
The Anchiornis
Imagine a small, crow-sized bird with long winged arms and long legs, covered in gray, white, and black feathers, and exhibiting a remarkable rufous crest formed by long feathers – this is Anchiornis!
The discovery of Anchiornis is one of the most significant paleontological events, as it’s one of the few dinosaur genera sharing so many similarities with modern birds and serving as a base for outlining their early evolution.
Additionally, Anchiornis is known as the first Mesozoic dinosaur whose plumage coloration has been fully reconstructed!
Keep reading if you want to discover more about this 160-million-year-old paravian dinosaur!
Physical Characteristics
Anchiornis was a bipedal paravian dinosaur.
It was quite small, measuring approximately 60–62 centimeters (23.6–24.4 inches) long and weighing 0.6-1 kilogram (1.3-2.2 pounds).
The wingspan was probably around 57.4 centimeters (22.6 inches).
Paleontologists discovered a small individual as well, which measured 34 centimeters (13.4 inches) long and weighed only 110 grams (3.9 ounces).
However, they suspect these remains belonged to a subadult or young adult.
Scientists generally compare Anchiornis to a crow in terms of size, although even crows may be slightly larger than these prehistoric dinosaurs.
Here are some other Anchiornis characteristics that specialists have outlined:
- It had a triangular skull that had dromaeosaurid, troodontid, and avialan traits.
- It had long, winged arms. The legs were also relatively long, as was the tail.
- The wings consisted of pennaceous feathers. They were attached to the arms and hands.
- The wings had three fingers each which, in turn, bore claws. The first two fingers were bound together.
- The hind legs were covered with long, vaned feathers, although they were not arranged as flight feathers.
- Each foot bore four toes and was completely covered in feathers.
- The underside of the toes had fleshy pads covered in small scales.
Of great interest to both scientists and wildlife enthusiasts is probably the plumage.
Paleontologists believe Anchiornis was covered completely in feathers.
The wings, legs, and tail had narrow, vaned feathers, while the rest of the body featured downy feathers.
The head was almost completely covered in long, simple feathers, which may have formed a crest.
The neck, torso, upper parts of the legs, and half of the tail had similar feathers.
The rest of the tail likely had pennaceous feathers.
Studies show that Anchiornis had a type of isolated contour feathers unknown in modern birds.
As scientists call them, these feathers were shaggy, open-vaned, and bifurcated.
They had long, flexible barbs sticking out from the quills, giving the feathers a forked shape.
Modern birds, on the other hand, have a rather smooth, aerodynamic plumage.
Upon closely studying the fossils and reconstructing Anchiornis, scientists concluded that the birds had been darkly colored, exhibiting a combination of gray and black feathers.
The face was blackish-gray and had noticeable rufous speckles.
The long feathers that may have formed a crest were distinctly rufous.
The body was likely grayish, except for the wing and leg feathers, which were a combination of gray, white, and black.
The feet and toes were black.
Habitat and Distribution
Anchiornis fossils have been unearthed only in Jianchang County, Liaoning, China.
More precisely, they were found in the Tiaojishan Formation and probably date back to approximately 160.89-160.25 million years ago.
As such, we can assume that these paravian dinosaurs’ distribution was limited to this territory.
However, let’s not forget that future paleontological findings can prove otherwise!
The Tiaojishan Formation had a subtropical to temperate climate.
The territory was warm and humid, and the ecosystem supported the growth of a wide variety of flora and fauna.
Plant fossils indicate that the habitat was dominated by gymnosperm trees (seed-producing plants), like conifers, cycads, and ginkgos.
Horsetails and ferns were also common.
Scientists have confirmed that the Late Jurassic Tiaojishan Formation was filled with deep lakes and mountain streams.
The gymnosperm trees probably formed forested areas that surrounded these water sources.
Behavior and Diet
First things first – could Anchiornis fly?
After all, this is the answer we’re most eager to discover when it comes to paravian dinosaurs!
Specialists initially thought Anchiornis was likely capable of flying or gliding.
Subsequent research, however, showed that its wings were shorter than its successors’ wings.
The Microraptor, for example, had longer wings with pointed feathers that supported aerodynamics.
In contrast, Anchiornis had rounded, symmetrical wing tips.
Today, it is generally believed that young Anchiornis could achieve flapping flight because they were still lightweight.
Nevertheless, this would have implied high-angle flapping.
Larger adults were likely too heavy to achieve aerodynamics.
Despite this, they may have used their wings while running and leaping.
Flapping their wings increased the running speed and leaping height and distance only a little, but it was still a gain because, despite their long legs, Anchiornis dinosaurs were not very good runners.
The long feathers that covered their legs, as well as the feathers on their feet and toes, slowed it down.
Studies discussing the Anchiornis’ shaggy feathers prove they may have played a role in altering heat retention.
They were also relatively ineffective for aerodynamic and water-repellency purposes.
The white and black feathers on the limbs may have worked well for escaping predators.
Some scientists compare this coloration to a zebra’s coat color.
Zebras are well-known for relying on their coat colors to dazzle predators, so Anchiornis may have done the same.
All things being clear until now, Anchiornis dinosaurs probably could not fly, were not very agile runners, and despite these disadvantages, they likely excelled at escaping predators (if any!) thanks to their plumage coloration.
But what did they eat?
Paleontological expeditions revealed fossilized gastric pellets that contained lizard bones and fish scales.
Some of these pellets were associated with Anchiornis, indicating that lizards and fish were part of its diet.
Based on this information, researchers concluded that Anchiornis was an opportunistic generalist hunter and likely had a diet similar to that of Microraptor.
Considering that fish scales were predominant in the pellets, it has been suggested that they represented an important part of Anchiornis’ diet, which came as a surprise to scientists because Anchiornis has no specific adaptations for catching and feeding on fish.
Unlike modern aquatic or shore birds, Anchiornis had feathered legs and feet and a relatively short snout.
As such, it hasn’t even been confirmed that Anchiornis was fond of water or lived near water sources!
Life Cycle
Upon studying the distribution of melanosomes in adult and younger individuals, scientists concluded that young Anchiornis did not have a rufous crest, which indicates this distinctive coloration may have developed as they matured.
As such, once they reached sexual maturity, the rufous crest probably played a significant role in courtship displays and sexual selection.
Additionally, the wing feathers may have also been used for display and communication.
Like all dinosaurs and modern birds, Anchiornis reproduced by laying eggs.
However, unlike modern birds, which have only one functional oviduct, Anchiornis and other theropods had two functional oviducts.
This means that Anchiornis laid two eggs at a time.
Many dinosaur offspring are known to be precocial.
This means they were relatively well-developed after hatching and could fend for themselves.
We hope future paleontological research will confirm whether this was true of Anchiornis as well!
Evolution and History
Anchiornis is part of the Paraves group, which includes all dinosaurs closely related to birds.
The members of this group diverged from other maniraptorans during the Middle Jurassic, approximately 165 million years ago.
Roughly 60 million years later, modern bird ancestors split from other paravians.
When the first Anchiornis specimen was discovered, paleontologists described it as a primitive member of Avialae, like Archaeopteryx.
The second, more complete specimen, however, revealed that it was, in fact, a troodontid – at least, at the time.
Then, it was placed in a group called Terapterygidae, a sister group of Avialae.
In the end, scientists classified it under the Anchiornithidae.
But even this family’s classification is doubtful.
Some consider it a basalmost family of Avialae, while others believe it’s a basal subfamily of Troodontidae or Archeopterygidae.
In short, Anchiornis shares traits with both dromaeosaurs and troodontids and, besides this, is very similar to avialans, and the family it’s part of has a doubtful classification.
Regardless of this taxonomic confusion, studying Anchiornis is essential to outlining the early evolution of birds.
For example, the gastric pellets associated with Anchiornis confirm that this dinosaur is the earliest theropod that produced gastric pellets, indicating that its digestive system was already similar to the digestive system of modern birds.
Besides this, like modern birds, Anchiornis has a complex plumage coloration, which was likely used in communication and display.
It’s important to mention that studying Anchiornis and outlining its role in the early evolution of birds was possible thanks to the abundance of fossils.
For example, China’s Shandong Tianyu Museum of Nature reported it possessed 255 Anchiornis specimens, and some of them included fossils with visible preserved color patterns!
Interactions with Other Species
The Tiaojishan Formation is rich in multiple dinosaur, pterosaur, amphibian, and insect fossils.
However, the territory did not reveal many lizard and fish species, which is of interest to us, as Anchiornis is known to have preyed on them.
We assume that since the habitat was filled with water sources, fish were likely abundant, and future paleontological expeditions may reveal some species.
As for the lizards, specialists found two lizard specimens, but they have not been identified.
Instead, we do know for sure that Anchiornis was not the only small dinosaur in the habitat.
It lived alongside Aurornis, Caihong, Eosinopteryx, and Pedopenna.
Of course, we cannot confirm how much interaction occurred between them, but it must have been quite a sight to see all these unique creatures walking on lake shores!
Salamanders were common as well, and Anchiornis may have even hunted them.
Pterosaurs like Daohugoupterus and Cascocauda were also present.
Other fascinating creatures in the ecosystem were docodonts like Agilodocodon, mammals like Arboroharamiya and Docofossor, euharamiyids like Maiopatagium, and arthropods like Mongolarachne.
It remains unknown whether any of these preyed on Anchiornis.
One could expect mammaliaformes to prey on Anchiornis, but most of the ones discovered in the Tiaojishan Formation were either small or had an insectivorous or piscivorous diet.
Cultural Significance
Without a doubt, Anchiornis is now among the most significant dinosaur genera.
It has often been described as an essential link between birds and feathered dinosaurs, thus carrying outstanding information that helps scientists understand the early evolution of birds.
Anchiornis is now one of the few extinct dinosaur genera with an identified and well-known feather morphology, which only adds to its importance in the avian lineage.
Of particular interest to scientists was the study of melanosome distribution, allowing plumage color reconstruction.
Dinosaur enthusiasts can see an Anchiornis specimen displayed at the Beijing Museum of Natural History.
Conclusion
Anchiornis was a four-winged paravian theropod dinosaur that walked through a territory we now call Liaoning in China.
It existed roughly 160 million years ago and lived among mammals, salamanders, pterosaurs, and other dinosaurs.
The near bird, as its name translates, is renowned for sharing multiple traits with birds.
Additionally, it is one of the few paravian dinosaurs whose feather morphology could be identified and described.
As such, Anchiornis is now reconstructed as a small bipedal dinosaur with a completely feathered body and a distinctive rufous crest.
The body was dark dray, while the forewing and hindwing feathers featured a distinctive gray-black-white pattern.
Although its wings were well-developed, Anchiornis probably could not fly, as its feathers are thought to have had decreased aerodynamic properties, and an adult would have been too heavy to fly.
Since its legs were also covered in feathers, Anchiornis was likely not a very good runner.
Instead, it may have relied on its plumage to confuse predators, if any.
Considering its similarity to extant birds, we’ll be on the lookout for future research papers discussing Anchiornis.
We’re sure these small dinosaurs will reveal many other secrets about the evolution of birds!
FAQs
What is the difference between Archaeopteryx and Anchiornis?
Here are three things that distinguish Archaeopteryx and Anchiornis:
- Archaeopteryx could probably fly, but scientists aren’t yet sure if it could engage in flapping flight or if it was a glider.
- Anchiornis likely could not fly.
- Archaeopteryx probably had no feathers on the head and upper neck, while the overall plumage coloration was black.
- Anchiornis, on the other hand, was fully feathered and had a rufous, gray, white, and black plumage coloration.
- Archaeopteryx evolved later in the paravian lineage, having lived roughly 150-148 million years ago, whereas Anchiornis existed 160 million years ago.
Sources:
- https://en.wikipedia.org/wiki/Anchiornis
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4730849/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6155034/
- https://en.wikipedia.org/wiki/Tiaojishan_Formation
- https://peerj.com/articles/2159/
- https://www.nature.com/articles/nature08322
- https://doc.rero.ch/record/210394/files/PAL_E4402.pdf
- https://research-information.bris.ac.uk/en/publications/additional-information-on-the-primitive-contour-and-wing-featheri
- https://www.nytimes.com/2017/12/15/science/anchiornis-dinosaurs-birds.html
- https://onlinelibrary.wiley.com/doi/full/10.1111/pala.12342
- https://www.nature.com/articles/s41598-018-32202-x
- https://www.science.org/doi/10.1126/science.1186290
- https://www.smithsonianmag.com/science-nature/dinosaurs-now-in-living-color-63116194/
- https://www.sciencedaily.com/releases/2019/01/190128161514.htm
- https://onlinelibrary.wiley.com/doi/abs/10.1111/1755-6724.13491
- https://www.nytimes.com/2010/02/05/science/05dino.html
About The Author
