Chongqing- Chinese paleologists have discovered two fossil repositories in Southwest China's Chongqing Municipal and Guizhou provinces, whose strata date back about 440 million years ago in the early Silurian period. These two fossil repositories named "Chongqing Special Buried Fossil Repository" and "Guizhou Shiqian Fossil Repository," add to China's world-class collection of buried fossils and fill a gap in the global fossil record of early Silurian jawed fossils. It is the first to provide definite evidence for jawed species' rise and earliest radiative differentiation.
An artist's impression of jawed fish dating back 440 million years. (Photo/CHINA DAILY)
Including humans, 99.8% of vertebrate species on the earth have jaws (upper jaw and chin), which are collectively referred to as jawed vertebrates or jawed animals. The emergence and rise of jawed species are one of the most critical steps in the evolutionary history of vertebrates, from fish to humans. Many important organs and body configurations of human beings can be traced back to the beginning of jaw evolution. But when, where, and how exactly does this happen? Paleontological evidence is needed to answer these questions.
The complete fossil record of jawed species did not appear until the late Silurian period (425 million years ago), and the molecular clock estimated the origin of jawed species no later than the late Ordovician Period 450 million years ago. Thus, there is a huge gap in the early evolution of jawed species that stretches for at least 30 million years and spans the entire Silurian period.
On September 28, the British journal Nature published four academic papers by the team of academician Zhu Min, who led the studies, focusing on the research results on the origin and earliest evolution of origin of the jaw.
Zhu said that the discovery of the two fossil repositories, for the first time in the history of paleontology, showed the Silurian fish, especially the jawed fish, and revealed the process of the rise of the early jawed species: 440 million years ago at the latest, the jawed species had flourished in South China; By the late Silurian period, more diverse and larger jawed species emerged and began to spread to the world, opening the process of fish landing and eventually evolving into humans.
The fossil research of the two fossil repositories traces many anatomical structures related to human beings back to ancient fish 440 million years ago. It fills the initial "missing link" in the evolutionary history of "from fish to human," updates the traditional understanding of the origin and rise of jawed species, and further consolidates the evolutionary path from fish to human.
Zhu said the two fossil repositories would continue to contribute to solving many mysteries related to the origin of jawed species in the future.
(Chen Qian, as an intern, also contributed to this report)