This list lists the oldest creatures on Earth, including animals, species and microbes, and you'll think you're young after reading it. Some people may criticize the list, thinking that some of these creatures are only a million years old, but in fact they are all quite ancient. So what are the oldest creatures on Earth?
1. Cyanobacterial bacteria
Age: 3.5 billion years old
The oldest known fossil of cyanobacteria has been found in the Archean rocks of Western Australia. The cyanobacteria bacterium, also known as the blue-green algae, is a bacterium that uses photosynthesis to generate energy. It is thought that this process promotes the formation of oxygen in the atmosphere, making the Earth more suitable for known life.
2. Sponge
Age: 580 million years old
Sponges originate from a primitive animal phylum, which dates back to the origin of life. Fossils of glass sponges have been found in rocks in Australia, China and Mongolia. Although about 90% of the sponges found today belong to the order of ordinary sponges, such sponge fossils are rarer than others because their bones are composed of relatively soft sponge hard proteins and are not easy to form fossils.
3. Jellyfish
Age: 505 million years old
Jellyfish and corals, hydras, monk's hat jellyfish, sea anemones, sea gills, sea whips and sea fans belong to the same genus of spiny animal phylum, also known as coelenterate phylum. Their bodies are almost made up of water, making it difficult to form fossils, but the existing fossil record suggests they are older than we thought.
4. Horseshoe crab
Age: 450 million years old
Horseshoe crabs are known as "living fossils", and the oldest horseshoe crab fossils date back to the Ordovician. These marine arthropods inhabit shallow seas with soft sandy or muddy bottoms. Their populations have been decreasing due to habitat destruction and overfishing.
5. Coelacanth
Age: 400 million years old
Coelacanths are a rare species of fish, more commonly called finfish, which are close relatives to lungfish, reptiles and even mammals. The last time live coelacanth was discovered was in 1998.
6. Ginkgo biloba
Age: 270 million years old
Ginkgo biloba is the only member of the Ginkgo biloba family, belonging to the gymnosperm phylum, dating back to the Permian period 270 million years ago. Due to the frequent occurrence of geological disasters, only three or four species survived in the Tertiary Period (65 million years ago). The extinction of dinosaurs, a potential medium for the spread of ginkgo seeds, may have had an impact on the decline of such plants, a hypothesis consistent with the fossil record.
7. Nautilus
Age: 235 million years old
The Nautilus, known as a "living fossil", originated at the end of the Triassic period and is a marine mollusk that means "sailor" in Greek. Nautilus is found only in the Indo-Pacific region, inhabiting the deep slopes of coral reefs.
8. Three-eyed dinosaur shrimp
Age: 200 million years old
This little guy is listed as the oldest extant species on Earth, surviving for 200 million years and remaining unchanged. In other words, the three-eyed dinosaur shrimp may not have existed as long as the top few on the list, but compared with its fossils 200 million years ago, its appearance has hardly changed today.
9. Sturgeon
Sturgeon and their close relatives, white sturgeon, have undergone very subtle changes in morphology, which shows that they have evolved slowly and that they deserve the honor of "living fossils". This also partly indicates that sturgeon have evolved over a long period of time and tolerated a wide range of water temperature and salinity. Due to their size, coupled with the abundance of food in the benthic environment, they have almost no natural predators.
10. Martian ants
Age: 100 million years old
Martian ant (martialis heureka, the original name roughly means "Wow! From Mars!") It is the most primitive species of ants, and its DNA has barely changed in the last 100 million years. The ants were discovered in the Amazon rainforest in 2000 AD and usually inhabit the ground.