380 million years!Science: the earliest heart long like this

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Australian researchers found a 380 million -year -old heart in an ancient jaw fossil, as well as separate stomach, bowel and liver fossils. This is the oldest heart found so far. This study shows that during the muddy basin period from 419.2 billion years ago to 358.9 billion years ago, the organs of the ducts that are currently extinct. Human evolution provides important clues.

Related research results were published on September 15th in Science.

These fossils were discovered in the GOGO group in the Kinberg area in western Australia. It was originally a huge coral reef. Kate Trinajstic, the author of the communications of the communications, the Academy of Molecular and Life of the University of Kotin, and the chief researcher at the Western Australian Museum, said that the soft tissue of ancient species was rarely preserved, and the three -dimensional preservation was more rare, so this discovery was very amazing.

"Evolution is usually considered a series of small steps, but these ancient fossils indicate that there is a bigger leap between jaw -free vertebrates and jaw vertebrates. Like sharks, "Trinajstic said.

The study first showed a complex S -shaped heart 3D model. This model consists of two chambers, and the smaller chamber is located at the top. These features are advanced in early vertebrates. In order to solve the change of the head and neck areas, it has begun to change to adapt to the jaw to provide a unique window. This is also a key stage for human body evolution.

However, TRINAJSTIC pointed out that a key difference is that the liver of this fish is large that can keep the fish's buoyancy, just like today's sharks. But today some hard bone fish, such as lungs and birch fish, have evolved from fish. "It is important that we did not find the evidence of lungs in any extinction of turtles, indicating that they later evolved independently in hard bone fish."

With the help of the Australian nuclear science and technology organization and the French European synchronization accelerator radiation facility, researchers used neutron beams and synchronous accelerators X -rays to scan the fossil specimens still embedded in limestone condensate, and according to bacteria and surrounding rock matrix deposition Minerals of different density build a three -dimensional image of the soft tissue inside the specimen.

In addition to the muscles and embryos that have been discovered earlier, the new discoveries of this mineralized organ make the GOGO group turtles become the most fully understood animal in all jaw drumped vertebrates, and clarify its existing jaw dried vertebrate ( The evolutionary transition of mammals, including humans).

John Long, a professor of the research co -author and a professor at the University of Finders: "The software discovered from these ancient fish is indeed what paleontologists dream of. There is no doubt that these fossils are the best fossils in the world in this era. . They show the major value of the GOGO group fossils in understanding the long evolution of human beings. The GOGO group is one of the most important fossil sites in the world. From sexual origin to the oldest vertebrate heart, it has created us in many worlds in the world. one."

Per Ahlberg, a professor at the University of Sweden, said: "The real special feature of the GOGO group fossils is that their soft tissue is preserved in three -dimensional space. Most of the cases preserved in soft tissue are in flat fossils in flat fossils It was discovered that the anatomy of the soft tissue there was just a point on the rock. We are very lucky because modern scanning technology allows us to study these fragile soft tissues without destroying them. It was impossible to do decades ago. "

Related thesis information:

https://doi.org/ 10.1126/science.abf3289

"China Science News" (2022-09-19 The 2nd edition of the original title of "380 million years! The oldest heart")

Edit | Zhao Lu

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