Living fossils in mammals
aardvark
Lived in the Jurassic-Pliocene. Also known as the African anteater, it is a nocturnal burrowing animal and the only animal in the order Pipetooth. From a genetic point of view, because of the arrangement of its chromosomes, the aardvark can be called a "living fossil". Elephants can be considered relatives of aardvarks, although the kinship is very distant.
opossum
A common name for the order Possum and possums. It is a relatively primitive marsupial, mainly from Latin America. Possums are primitive, low-class mammals. Fossils very similar to the living American possum were first found in the late Cretaceous strata, showing that the possum is a fairly old population in marsupials. In the late Cretaceous period, 65 to 90 million years ago, North and South America were still closely linked.
Weasels
The ancestor of the living shrew deer is the (ancient) shrew deer, which appeared in the Late Eocene. The (ancient) moose is also likely to be the ancestor of ruminants, and some of its main features are similar to those of living moose, with a body size like a rabbit, no horns on the head, slender limbs, a curved back, but with a longer tail, relatively long feet, and the metacarpal and metatarsals are separated, all teeth are present, but the 3 upper incisors are smaller and are obviously tending to disappear.
tapir
Tapirs are herbivores, shaped like pigs, but larger than pigs, and survived in warm, humid environments between 1 million and 10,000 years ago, mainly in South China. However, due to environmental changes, the giant tapir became extinct about 10,000 years ago. With the exception of its "close relative" in Southeast Asia, the Asian tapir, there are only four other species left, and the rest have all become extinct.
Living fossils of amphibians and fish
Purple frog
The purple frog is a type of frog with a purple body, belonging to a frog that only exists in the Seychelles, with a mouth very similar to that of a pig, and spends most of the year underground at a depth of 4 meters. This frog belongs to a branch of a special species of frog that lived during the ancient dinosaur period. Purple frogs were only discovered in India in 2003 because they live underground, appearing only for two weeks during the rainy season and living invisibility the rest of the time
Arowana
As far back as the Archaic Carboniferous period, three and a half million years ago, arowana belonging to the Osteoglossidae family began to exist. The oropharyngeal family is the only family of freshwater fish found on both sides of the Wallace Line. 140 million years ago, Arowana migrated to the Asian and Indian subcontinents, and the movement of the Earth's crust gradually spread them to all continents of the world.
Coelacanth
The coelacanth has a wide range, but from 100 million years ago it began to decline, and by the end of the Mesozoic Era 75 million years ago, its traces disappeared from the earth, leaving only fossils. Before 1938, most scientists thought that coelacanth had become extinct as early as 60 million years ago. It was not until 1938 that live coelacanths were found in South Africa.
lungfish
It is a species of teleost fish and lungfish subclass, there are only 3 families, 3 genera and 6 species of wild species, which once multiplied in large quantities on the earth in ancient times, and now only a few of them have preserved their races and remained, so they are called "living fossils".
Sea lily
During the Paleozoic Carboniferous period, the number of sea lilies was extremely large and varied, and could be classified under several categories under the "General Order of Sea Lilies". (A type of sea lily from the Early Jurassic period is a typical example).) Later, due to the "Permian and Triassic extinction events", 90% of marine species went extinct, and sea lilies quickly withdrew from the historical stage. When the living species of sea lilies were first rediscovered, they were in deep waters, so it was initially thought that they could only survive in the deep sea. It was later discovered that it could be found in shallow or deep seas, tropical coral reefs or high latitudes.