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A hundred million years ago, the fierce ancient birds were small and fierce

Original title: what happened to ferocious ancient birds 100 million years ago to provide key information for understanding the evolution of ancient birds

In recent years, paleontology found in amber has attracted many netizens' attention. On the 30th, a team of Chinese and foreign scientists announced once again that traces of a 100 million year old miniature Raptor were found in amber, providing key information for us to further understand the evolution of ancient birds.

Scientists at home and abroad found amber of ancient birds 100 million years ago

On October 30, a team of Chinese and foreign scientists announced the discovery of a very special fossil of ancient birds in amber. The details are of great significance to our understanding of the diversity of ancient birds and the evolution of feathers. This research is led by Xing Lida, associate professor of China University of Geosciences (Beijing), Niu Kecheng, executive director of Yingliang world stone natural history museum, Professor Ryan Middleton, Royal Museum of Saskatchewan, Canada, and Zou Jingmei, an American researcher of Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences. The research paper was published in the scientific report of the international well-known academic journal and natural group.

In 2016, Xing Lida's team discovered the world's first ancient bird wings and dinosaurs in amber, and then found nestlings, complete ancient birds, frogs and snakes in amber. In the past three years, Myanmar amber about 100 million years ago produced a series of immature anti bird skeleton fossils, with different stages of development and integrity. With the discovery of more and more fossils, the ancient bird fauna is gradually forming, which greatly deepens our understanding of ancient birds, especially anti birds. 'about Xing Lida.

Toes prove that the new bird is a small Raptor

The research samples of scholars come from the famous amber producing area, hukang River Valley, Kachin state, northern Myanmar. Hukang River Valley is located in the northernmost part of Myanmar, the upper reaches of qindun River, which is composed of Daro basin and xinpingyang basin, with high mountains and dense forests, crisscross rivers and overflowing in rainy season. Burmese is' where the devil lives'. It is said that there were savages in the area, so the local people call the area "savage mountain". Amber here is about 100 million years old, providing a unique forest ecosystem record.

The newly discovered ancient bird amber is collected by Yingliang world stone natural history museum, Quanzhou City, Fujian Province. There are not many foot skeletons in Yingliang specimen, but the outline of the foot has been recorded by the detailed skin, and there are a lot of hairs on the surface of the foot skin of these ancient birds. In addition, the specimen also has a very rare feather axis dominant type feather.

The foot of Yingliang bird is about 7 mm long. Micro CT provides a detailed, three-dimensional anatomical structure for this small specimen. Through the proportion of foot and feather shape, the researchers classified this specimen as anti bird. The overall shape of the foot and the curvature of the well preserved cuticle sheath strongly suggest that it is a arboreal bird. 'in particular, Yingliang specimen has large and curved claws, which are flat and have the same cross-sectional shape as the living arboreal birds, but different from the terrestrial species; secondly, the distal phalanges of specimen are relatively long, which is the characteristic of arboreal birds, while the proximal phalanges of terrestrial birds are longer. 'Xing Lida explained.

The most interesting thing about the new specimen is that its toes are very thick, which is different from all the previous bird fossils found in the area. The outer toe, also known as the fourth toe, has a laterally elongated toe pad that is very thick relative to the two inner toes (the second and third). Simply put, the fourth toe is wider than the second or third toe, and its protruding foot pad and protruding foot bottom surface may be related to catching prey. The strong toes with claws are similar to the living raptors, which may indicate that Yingliang specimen is a small aerial insectivorous bird. 'said Xing Lida.

The specimen reveals the feathers of ancient birds or plays a tactile role

In addition, Professor Ryan Middleton mckeller told reporters: 'in the specimen we described this time, there are cuticle scale filaments in each toe, and they are densest and longest at the base of the second toe. Horny scale filaments are rare in the nestlings of modern birds and do not seem to exist in adult birds. The cuticle scale filamentous feather of this specimen may play a role of tactile to help it catch small prey such as insects. 'so far, horny scale filaments have been found on the feet of all the anti birds found in the hugang bird group, and they seem to be more obvious in the older individuals, or more developed in some species.

The feather axis dominated feather in amber is a new discovery made by Xing Lida's team at the end of 2018. Its biggest feature is the open feather axis, which forms an efficient light tail feather. That is to say, the opening of feather axis may be a measure to save energy, reduce the energy consumption of growing this long feather, or the structure is specially evolved for the long and light tail feather. At present, paleontologists believe that plume axis dominated plume is a tool for intraspecies information exchange of ancient birds, and its main functions are courtship display, species identification and visual communication. "No bone material has been found near the feather axis dominated feather found before, but only anti bird remains have been found in amber in Myanmar so far, so these strange feathers are temporarily classified as anti bird. The specimen found here is the first evidence that the dominant plume of feather axis can be directly corresponding to the anti bird remains. "Said Zou Jingmei, a paleontologist.

In general, Xing Lida said, the toes of Yingliang specimen are wider than any anti bird previously observed in Burmese amber. This unique foot shape reflects the differences in the way birds catch prey. This type of foot has not been found in the local fossil record, which shows the diversity of birds in the dinosaur era, far beyond our imagination. There is increasing evidence that the hugang avifauna is unique compared with other Cretaceous fauna.