Today, most vertebrates have teeth, but from a paleontological point of view, this is a relatively new evolutionary process that occurred more than 400 million years ago. Chinese scientists were lucky enough to discover fish fossils from this period, which may be the first shark on Earth.
This new fish, although not terrible, was a dangerous carnivore by the standards of the time. Before the appearance of teeth and jaws, our ancestors, ancient vertebrates, digged in soft seabed sediments, filtered small animals. Without attacking the organ, they may accidentally suck a small beetle , worm or smaller relative into their mouths.
However, about 425 million years ago, an evolutionary innovation emerged in primitive fish, which determined the further development of vertebrates. In some jawless animals, the gill arc originally used to support the respiratory system moves forward and becomes the first jaw.
Around the same time, the first batch of real teeth appeared, which were deprived of the early jawless fish .关于它们的起源有几种理论，包括由鱼鳞或喉咙角质形成的发育，但最终牙齿和下颚形成了一个单一的装置，用于抓取和保持大型、积极抵抗的猎物。
Now, Chinese scientists have described an ancient toothed fish: a new species called Zianodos Duprisci, about 443-41.9 billion years ago. The fossils were discovered in Guizhou Province, southern China in 2019 and exhibited a peculiar curl of teeth with several long and sharp teeth on them. These teeth are at least 14 million years older than any other teeth found by paleontologists.
qianOudong head reconstruction: Pay attention to the spine-like curl at the end of the animal's jaw
The emergence of vertebrate teeth led to the explosion of biodiversity , and soon, many animals that can bite and tear their prey floated in the ancient ocean. Ancient jawless fish soon lost their role in the ecosystem. By the time the Devonian began, 419 million years ago, ancient cartilage and bone fish had reached an unprecedented diversity , which was called the "Fish Age".
This study was published in the journal Nature
