"Experiment of evolution": in China, found the remains of unusual birds age 127 million years

SL, Вторник 25 Сентябрь 2018 - 15:38:08

Chinese paleontologists have discovered the remains of fossil birds that lived on the planet about 127 million years ago (Cretaceous period). The value of the findings is enormous, scientists say. First, the remains belong to a previously unknown bird species, and secondly, it seems that this species is a missing link in the evolution of flight.

Researchers from China have named a new species Jinguofortis perplexus. They specify that the remains were found in the Eastern part of China, in Hebei province. In the lower chalk, the region was covered with dense forests and lakes: this was the habitat of J. perplexus.

A study of the remains showed the ancient bird can safely be called a transitional link between dinosaurs and birds. The creature was devoid of massive bony tail, but haven't got a full pen cover, characteristic of modern flying birds.

Wingspan J. perplexus was about 27 inches. Members of the species had claws with partially fused phalanges (a sign of the simplification of the skeleton to adapt to the flight) and jaw with tiny teeth instead of a beak. However, researchers found remnants of stones in the stomach, which indicates a plant-based diet.

But most paleontologists are interested in the structure of the shoulder girdle.

The head of the research group Ming Wang (Min Wang) of the Chinese Academy of Sciences explains that usually the evolution of the aircraft of birds is represented as a gradual transition: they have grown more feathers and changed the structure of the skeleton and, consequently, muscle.

"However, this new fossil birds shows that the evolution of flight was much more chaotic," Wang said.

J. perplexus his team noticed a sort of anomaly. The fact is that in modern birds the shoulder girdle consists of the shoulder blades and coracoid, which provides flexibility during landing. However, representatives of the new species these bones are fused into one – scapulocoracoid.

This fused structure is responsible for the mobility of the muscles and wings during flight. This is a "very unusual feature" for flying birds, said Gerald Mayr (Mayr Gerald), an expert on the evolution of birds from Senckenberg research Institute in Frankfurt.

He believes that scapulocoracoid may indicate the existence of different styles of flight from the earliest stages of avian evolution.

"If it is confirmed in future studies, it may inspire new ideas about how these early birds used their wings," — says Mayr.

However, it is clear that J. perplexus could fly. His feathers were, apparently, too narrow for flying birds. And fused the shoulder structure can be typical of flightless species, for example, ostriches.

However, van still leans to the version that J. perplexus was able to fly, but not quite familiar to modern birds. In his opinion, the evolution of flight is much more difficult than expected, because the ancient bird species demonstrate different ways of development of skeletons and the use of aircraft.

One of the reviewers of the scientific article, a paleontologist from the University of Edinburgh Steve Brusatte (Steve Brusatte), believes that J. perplexus can be a kind of evolutionary experiment. Probably birds did not develop all the functions needed to direct a "classic" flight, and had different "styles", said the researcher.

According to him, future works should pay attention to not only the structure of the shoulder girdle, but also the evolution of the tail. Birds are gradually "changed" long and straight tails on the short "model". So, individuals open type tail vertebrae are shortened and fused, forming a single bone. It was the likeness of pygostyle, coccygeal bones of most modern birds, which serves as a support for the tail feathers.

Another interesting detail is the name Jinguofortis perplexus selected Chinese paleontologists. The genus name honors women scientists worldwide, experts explain. It is formed of the words "if", which in Chinese means "woman warrior" and "fortis", translates from Latin as "brave." But the specific name of "perplexus" can be translated as "ambiguous and confusing". This is a reference to the mixed signs, that combined members of the species.

Learn more about this discovery and its study described in the article published in the journal PNAS.

By the way, the authors of the project "Conduct.Science" (nauka.vesti.ru) talked about the evolution of singing birds, and the evolution of the beaks of ancient birds.

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