Scientists said in 2013 that they discovered a 419 million-year-old fish fossil in China, which refuted the long-standing theory that modern animals with skeletons evolved from shark-like creatures with cartilage frameworks.

paleontologists have reconstructed tiny bone fragments unearthed in China, which belong to a creature with an external body "armor" and several pairs of fin spines that separate it from jawed fish such as cartilage sharks and rays .

The research team also found about 20 teeth from this new species called Fanjing Mountain, which allowed them to determine that they might only come from a fish with an arched jaw margin similar to a modern shark.

These fossils “help to trace many of the human structures of to ancient fish about 440 million years ago and fill some key gaps in the evolution of ‘from fish to humans’,” said Chinese Academy of Sciences .

This study also produced other fossils, especially those who revealed that the extinct jawless fish members galeaspids possess paired fins.

Professor Zhu Min of the Chinese Academy of Sciences in Beijing said in a statement: "This is the oldest jawfish in known anatomy.

"The new data enables us to place Vanjingshanniya into the family tree of early vertebrates and obtain much-needed information about evolutionary steps leading to the adaptive origin of important vertebrates, such as jaw bones, sensory systems and paired appendages. ”

Scientists said in 2013 that they discovered a 419 million-year-old fish fossil in China, which refuted the long-standing theory that modern animals with skeletons (osteichthyans) It evolved from a shark-like organism with a cartilage frame.

Ancient ancestors of humans were found in the bone bed sample of Rongxi Formation at a site in Shiqian County, Guizhou Province, southern China.

Fanjing Mountain has several characteristics that are different from any known vertebrate animals, especially the dermal shoulder strap plate, which fuse as a unit to many pricks—sternum, chest and pelvic front.

Paleontologists have reconstructed tiny bone fragments unearthed in China. The picture shows fragments of thoracic bones

This life The fin spines of the object are one of the greatest discoveries, as this feature helped scientists determine the location of new species in the early vertebrate evolutionary trees. The

research team also determined that the skeletal fossils of the Fanjing Mountain fish showed reabsorption (cells or tissues were absorbed into the circulatory system) and remodeling, which is usually associated with the bone development of the bone fish, including humans. The reabsorption characteristics of the Fanjing Mountain are most evident in isolated torso scales, showing evidence of tooth-like shedding of the tooth crown element and removal of dermal bones from the base of the scales.

lead author, researcher at Qujing Normal University "This degree of hard tissue changes is unprecedented in cartilage fishes, including modern cartilage fish and its extinct ancestors," Dr. Plamen Andreev said in a statement.

"It illustrates that at the beginning of jawfish diversification, the developmental plasticity of mineralized bones is greater than what is currently known."

The team also found a complete skeleton of an extinct jawless ocean and freshwater fish taxa in the rocks of Hunan Province and Chongqing, and named the Tujia fish after the Tujia people living in the area, containing their entire bodies.

Until now, only fossils of the heads of these creatures have been found.

These fossil remains reveal the first evolution of paired fins.

"There are tens of thousands of fossils known to be from China and Vietnam , but almost all of them are just the head - know nothing about the rest of them - until now."

"These new fossils are spectacular, preserving the entire body for the first time and revealing that these animals have pairs of fins that extend from the back of the head to the tail tip."

corresponding author Professor Donoho said: "Tujiaaspis Injected new vitality into the century-old hypothesis of paired fin evolution, by differentiating pectoral fins (arm) and pelvic (leg) fins from continuous head to caudal fin precursors over evolutionary time.

'This 'fin fold' hypothesis is very popular, but until now there is no supporting evidence.