Why is speartail fish a living fossil?
The Earth is 4.6 billion years old, and since its birth 3.2 billion years ago, life has produced countless creatures of all kinds, each of which has undergone a long period of evolution to become what it is today. According to research, organisms with slow evolution have a low rate of formation, and they are highly adaptable to food sources and living environment fluctuations, while new species that survive in the same environment may not be competitive. Germination is an important part of biological evolution, and these organisms will not change much over millions of years under the condition that the living environment is extremely low. As a result, some ancient creatures were formed, and other creatures of the same era had long since become extinct, and only they remained alone, living in a very small area, called "living fossils".
Living fossil species have a history of at least tens of millions of years, retaining many primitive features throughout geological history without major changes, and belong to a class of slow-evolving organisms. Speartail is the only species of coelacanth in the family Speartail and the only living total fin fish. The same fish, why is it called a "living fossil"?
Paleontologists have found from fossil studies that from the beginning of the Devonian Period about 400 million years ago to the end of the Cretaceous Period 65 million years ago, a class of coelacanths lived on earth. Coelacanth fish were once as widely distributed on Earth as dinosaurs, and the typical representative of the ancient coelacanth fish is the large cover fish, of course, this fish can only be seen in fossils today.
We all know that there are no such creatures as dinosaurs now, so it is easy to think that other species of the same era as dinosaurs have also become extinct. Coelacanth fish should be no exception, in the late Cretaceous period gradually disappeared, do not know where to go, and in fact has not been found after the Cretaceous cretaceous fish fossils. It was not until December 22, 1938, that in the city of East London, South Africa, a "strange fish" that modern people had never seen before appeared, and it was extremely similar to the shape of the ancient large cover fish. The discovery shocked the scientific community. Because the tail fin of this fish is divided into three lobes, between the upper and lower leaves, along the midline of the body axis, there is also an additional leaflet, and the entire tail fin is spear-shaped, so it is called speartail fish in China.
Species that existed in the same era have become extinct, and the speartail fish found today is the only species that existed in that era, and like many fossils, it has a long history, so people call the speartail fish "living fossil".
