The first known fossil of Anchiornis (its type specimen) was dug up in the Yaolugou area of Jianchang County, Liaoning, China.
These rocks have been difficult to date, but most studies have concluded that they belong to the Tiaojishan Formation of rocks dated to the late Jurassic period (Oxfordian age), 160.89 to 160.25 million years old.
studied and described by paleontologist Xu Xing and colleagues in a paper accepted to the Chinese Science Bulletin in 2009.
The specimen is currently in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology with the catalogue number IVPP V14378.
It is an articulated skeleton missing the skull, part of the tail, and the right forelimb.
The name Anchiornis huxleyi was chosen by Xu and colleagues in honor of Thomas Henry Huxley, an early proponent of biological evolution, and one of the first to propose a close evolutionary relationship between birds and dinosaurs.
The generic name Anchiornis comes from combining the Ancient Greek words for "nearby" and "bird", because it was interpreted as important in filling a gap in the transition between the body plans of birds and dinosaurs.

A second specimen came to light around the same time, and was given to a team of scientists from Shenyang Normal University by a local farmer when they were excavating at the Yaolugou dig site.
According to the farmer, this second specimen had been found nearby in the area of Daxishan, also from Tiaojishan Formation rocks of about the same age as the first Anchiornis.
Two scientists visited the site in order to compare the new fossil with the rock types found there, and were able to confirm that the new specimen probably did come from the area the farmer described.
They were able to dig up several fish fossils and a third Anchiornis fossil.
The farmer's fossil underwent study which was published on September 24, 2009, in the journal Nature.
It was assigned the catalogue number LPM – B00 169 in the Liaoning Paleontological Museum.
It is larger and much more complete than the first specimen, and preserved long wing feathers on the hands, arms, legs and feet, showing that it was a four-winged dinosaur similar to Microraptor.

While only a few specimens have been described in detail, many more have been identified and are held in both private collections and museums.
One of these, a nearly complete skeleton missing the tail, also preserving extensive feather remains, was reported in 2010.
This fossil also showed evidence that Anchiornis had a feathered crest on its head, and was used to determine the animal's life coloration.
It is housed in the Beijing Museum of Natural History with the specimen number BMNHC PH828.
Another specimen from the same fossil quarry as the type specimen was found by a local fossil dealer and sold to the Yizhou Fossil & Geology Park and catalogued there as YTGP-T5199.
This fossil, a nearly complete skeleton, was prepared and studied by scientists at the Geology Park and identified as an Anchiornis.
It was then used for a scanning electron microscope study of Anchiornis feather microstructure.
The study also examined the well-preserved melanosomes of the feathers to determine their color.
The scientists involved in the study found that the coloration found for this specimen was different than the color reported for BMNHC PH828, and they noted that the BMNHC specimen may not in fact be Anchiornis, as it was described before similar species from the same formation had been discovered.

The Shandong Tianyu Museum of Nature in Pingyi County, China, for example, was reported to hold 255 specimens of Anchiornis in its collections in 2010.
Among their collection is a very well preserved fossil with visible color patterns, catalogued as STM 0-214.
While this specimen has yet to be fully described, it was photographed for a 2011 article in National Geographic and was used in a study of Anchiornis covert feathers and wing anatomy the following year.
The first known fossil of Anchiornis (its type specimen) was dug up in the Yaolugou area of Jianchang County, Liaoning, China. These rocks have been difficult to date, but most studies have concluded that they belong to the Tiaojishan Formation of rocks dated to the late Jurassic period (Oxfordian age), 160.89 to 160.25 million years old. studied and described by paleontologist Xu Xing and colleagues in a paper accepted to the Chinese Science Bulletin in 2009. The specimen is currently in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology with the catalogue number IVPP V14378. It is an articulated skeleton missing the skull, part of the tail, and the right forelimb. The name Anchiornis huxleyi was chosen by Xu and colleagues in honor of Thomas Henry Huxley, an early proponent of biological evolution, and one of the first to propose a close evolutionary relationship between birds and dinosaurs. The generic name Anchiornis comes from combining the Ancient Greek words for "nearby" and "bird", because it was interpreted as important in filling a gap in the transition between the body plans of birds and dinosaurs.
A second specimen came to light around the same time, and was given to a team of scientists from Shenyang Normal University by a local farmer when they were excavating at the Yaolugou dig site. According to the farmer, this second specimen had been found nearby in the area of Daxishan, also from Tiaojishan Formation rocks of about the same age as the first Anchiornis. Two scientists visited the site in order to compare the new fossil with the rock types found there, and were able to confirm that the new specimen probably did come from the area the farmer described. They were able to dig up several fish fossils and a third Anchiornis fossil. The farmer's fossil underwent study which was published on September 24, 2009, in the journal Nature. It was assigned the catalogue number LPM – B00 169 in the Liaoning Paleontological Museum. It is larger and much more complete than the first specimen, and preserved long wing feathers on the hands, arms, legs and feet, showing that it was a four-winged dinosaur similar to Microraptor.
While only a few specimens have been described in detail, many more have been identified and are held in both private collections and museums. One of these, a nearly complete skeleton missing the tail, also preserving extensive feather remains, was reported in 2010. This fossil also showed evidence that Anchiornis had a feathered crest on its head, and was used to determine the animal's life coloration. It is housed in the Beijing Museum of Natural History with the specimen number BMNHC PH828. Another specimen from the same fossil quarry as the type specimen was found by a local fossil dealer and sold to the Yizhou Fossil & Geology Park and catalogued there as YTGP-T5199. This fossil, a nearly complete skeleton, was prepared and studied by scientists at the Geology Park and identified as an Anchiornis. It was then used for a scanning electron microscope study of Anchiornis feather microstructure. The study also examined the well-preserved melanosomes of the feathers to determine their color. The scientists involved in the study found that the coloration found for this specimen was different than the color reported for BMNHC PH828, and they noted that the BMNHC specimen may not in fact be Anchiornis, as it was described before similar species from the same formation had been discovered.
The Shandong Tianyu Museum of Nature in Pingyi County, China, for example, was reported to hold 255 specimens of Anchiornis in its collections in 2010. Among their collection is a very well preserved fossil with visible color patterns, catalogued as STM 0-214. While this specimen has yet to be fully described, it was photographed for a 2011 article in National Geographic and was used in a study of Anchiornis covert feathers and wing anatomy the following year.
Anchiornis