There are animals that survived geological fluctuations millions of years ago and still exist today.
The father of the theory of evolution, Chales Darwin was the first to invent the term “living fossils” in his pioneering book “The Origin of All Species” in 1859. He used this term to describe species. life resembles the prehistoric species that once existed on Earth.
However, the classification of animals as “living fossils” is controversial in the scientific community because it implies that some species today have ceased to evolve and remain unchanged from their ancestors.
The truth about “living fossils”, such as crocodiles, is that they have very similar characteristics to a species that lived millions of years ago. To be classified as a living fossil, a species must have a significantly slower rate of material evolution or subtle changes in morphology (physical).
Here are 5 species of animals that are equated with “living fossils” on earth due to their long existence:
Nautilus
The dandelion is the only mollusk with a completely self-contained shell.
On Earth, there aren’t many species that live long enough to see the rise and fall of dinosaurs, but the dandelion certainly can. Become a giant of the ocean around 500 million years ago, these ancient mollusks have successfully survived thanks to their natural armor. The Anh Vu snail is the only mollusk to have a completely autonomous shell, thanks to a meat trap that protects the mollusks hidden inside.
At first glance, the Anh Vu snail may look like a hanging snail, passively following the flow of water with no fins or limbs to control its cruise. However, he uses a water jet to push himself. Through a suction nozzle (a line connecting living tissue to internal cavities in the shell), the snail can suck and pump water, creating a thrust that allows it to move back and forth. It uses the same method for moving up and down: after pushing water out of the shell, snails can float and move upwards, and as they suck more water, they sink.
Although this unique construction has helped them last for millions of years, they are now endangered by hunters for their beautiful seashells.
Crocodile
250 million years ago, the ancestors of today’s crocodiles began their first steps on Earth.
As a symbol of living fossils, crocodiles have long been an example of “if something’s wrong, it doesn’t need to be fixed” when it comes to evolution. At the start of the Mesozoic, about 250 million years ago, the ancestors of today’s crocodile today began their first steps on Earth. At the end of the Cretaceous, around 65 million years ago, prehistoric marshes and riverbeds were home to amphibian predators, no different from the crocodiles we see today.
With a long, muscular muzzle, scaly armor, and short legs, the crocodile’s body structure is said to have evolved from a need to explore new hunting grounds because dinosaurs had conquered the continent. Crocodiles have evolved to accommodate new underwater habitats. The eyes, ears and nose are on the head, so crocodiles keep them on the water when the rest of the body is submerged in the water and a muscular tail like a fin gives them strength and maneuverability under the water. water.
Although we have strong evidence that modern crocodiles have held their shape for millions of years, the lineage of this species has also varied.
Tuatara
Tuatara was seen all over the world in ancient times.
Currently only found in New Zealand, but previously Tuatara has been seen around the world. This lizard-like reptile was previously considered a member of the lizard family, but after careful examination and tracking of fossil traces from over 200 million years ago, it was concluded that this reptile is a member of a separate order known as Rhynchocephalia, of which Tuatara is the sole representative.
There were 24 genera of the genus Rhynchocephalia that existed on Earth, but competition with other better adapted reptiles, such as crocodiles, led to all of them becoming extinct about 100 million years ago, except for one Tuatara genre which still exists to this day.
Horseshoe crabs
Their evolution has taken place so slowly that they have been considered “living fossils”.
Despite the name, horseshoe crabs are not crabs but they belong to a group of invertebrates belonging to the arachnoid class and closely related to spiders and scorpions. However, because their shells look like crustaceans, it is very confusing.
First seen on the ocean floor over 300 million years ago, the horseshoe crab has appeared continuously since then. Although unlike their prehistoric ancestors, their evolution took place so slowly that they were considered “living fossils”. Clad in a powerful horseshoe-shaped shell, these “armored spiders” are a difficult meal for prehistoric and modern predators.
Although horseshoe crabs are not known for their ability to swim and are usually only seen when crawling out of the water, they are equipped with a long, spiked tail that acts as a rudder. In the event that they are flipped upside down, this tail acts as a lever to tip them over.
Each summer on the coasts of the United States, swarms of Atlantic horseshoe crabs often ascend out of the water and onto beaches to breed.
Coelacanths
The coelacanth is just one of two groups of fish swimming near the lobe fin.
While diving in the deep seas around the Comoros Islands in Africa, you may be lucky enough to spot a living fossil swimming near the seabed. With a length of up to two meters, it is difficult to miss this animal. Once thought to be extinct, coelacanths have stood the test of time and have remained physically unchanged for more than 360 million years.
There are currently two species of fish – Latimeria chalumnae living in the seabed off East Africa and Latimeria menadoensis – which swim deep in Indonesian waters. What makes these giant fish so special are their fins. Usually, today’s bony fish breeds have stingray fins, which means their fins are made up of bony spines. The coelacanth is just one of two groups of fish swimming near the lobe fin. Much like the way the bones of their legs were connected to the pelvis, the fins of the lobe contained an internal skeletal structure that led scientists to believe that their ancestors could be linked to the evolution of limbs. life has four kinds). However, having lobed fins makes this fish feel like it has grown legs.
