The first thing that comes to mind when we hear “prehistoric animals” are the well-known dinosaurs, ancient fossil reptiles of different sizes that inhabited the Earth millions of years ago and that today are the protagonists of many science fiction stories and movies. However, it is important to point out that not only did these specimens exist on our planet, but many other animals that today can still be found alive in nature or that, due to evolution, have already become extinct.
What is a prehistoric animal?
We usually think that prehistoric animals are those that, as their name indicates, belonged to the stage of prehistory and that are now extinct. In fact, we are not entirely wrong, but if we look at the definition of prehistory offered by the Dictionary of the Royal Spanish Academy (RAE), the concept we have of these animals may be broader. Thus, we can consider as a prehistoric animal that which appeared in a period of humanity prior to any written document and that we know today thanks to the study of fossils, remains and bones found. This does not mean that practically all the animals that arose with the origin of the planet have disappeared, since today there are still many very old species that have managed to survive over the years.
In short, we can define prehistoric animals as all those species that emerged more than 3,500 years ago. C, being classified into two groups: those already extinct and those that are still alive. Both are the origin of the different species of animals that exist today.
Characteristics of prehistoric animals
If we go back to the first animals that set foot on the planet, it is important to talk about the appearance of tetrapods, that is, those that developed four extremities to be able to move on land and not only in aquatic environments like the first fish and sponges. These are amphibians, which continued to have fish-like features. Later, with the development of the amniote egg, which allowed greater independence in the terrestrial environment, reptiles and birds appeared. Some characteristics of all these tetrapods were and are the following:
- Its typical members were made up of 5 segments: the long bone or femur, two long bones (tibia and fibula), the carpal bones (wrist), the tarsals (ankle), the metacarpals (palmar), the metatarsals (plantar) and those that make up the phalanges or fingers.
- They adapted to the terrestrial environment by developing structures such as scales, hairs or feathers that have favored the loss or gain of heat. They have also developed behaviors aimed at thermal regulation, such as hibernation.
- There have always been herbivorous and/or carnivorous species being able to hunt alone or in packs.
- In most animal groups there has been a hierarchical structure, with the largest being the most powerful, usually.
Live prehistoric animals
As we have already mentioned, thousands and millions of years ago the first animals appeared and not all of them are extinct today. These are some prehistoric species and animals that have managed to remain on our planet for a long time:
Alligator Turtle (Macrochelys temminckii)
These large and ancient reptiles, which appeared approximately 66 million years ago, are typical of the American continent and are mainly characterized by its shell with rows, since it has elevations similar to small horns. In addition, they have a large head and a longer snout than other species of turtles. They can weigh around 100 kilograms.
The alligator turtle lives in freshwater environments where it feeds on fish. To do this, it camouflages itself among the algae and uses its striking tongue, which has a kind of projection on the tip like a worm, to attract small fish and devour them when they least expect it.
Eel shark (Chlamydoselachus anguineus)
It is one of the oldest sharks that exist, which is why it is also part of the list of living prehistoric animals, since they appeared on Earth 140 million years ago Its name refers to its great resemblance to eels, although unlike them, it does have a dorsal fin. The eel shark is characterized by having a long body similar to that of a snake (2-4 meters) and a flattened head with nostrils at the front.
This large fish lives in deep sea waters where it feeds mainly on other small animals such as some fish and squid. Thanks to the morphology of its body, it can reach great speeds to capture its prey, something that is favored by its white and shiny teeth, which has served as an attractant for small fish. By the way, did you know that it has more than 300 teeth?
If you want to know more Prehistoric Marine Animals, don't miss this other article.
Pelican (Pelecanus spp.)
It emerged approximately 30 million years ago and it is a large aquatic bird, although the males exceed the females by several centimeters. It is known for its large beak, which has a "gular bag" where it stores food. Its plumage can take on various colors, but it usually has white, grayish or brown tones. This bird has the ability to transform and process the s alty water it takes from the environment to make it digestible.
The pelican usually nests in areas near the coast, because, as a piscivorous animal, it spends much of its time feeding on fish and, although most of the time we see it perched in the water, he is also a very good flyer.
Sea sponges
They belong to the phylum of the porifera, invertebrate animals found on the seabed and attached to the substrate. The data indicates that could have emerged around 760 million years ago being able to adopt different shapes and colours, although they all have in common the inexistence of authentic fabrics, since their cells are totipotent and are constantly dividing, transforming into any cell type.
They are sessile and feed through a filtering process, since by circulating water through a series of pores, channels and chambers of the sponge, they obtain the necessary nutrients. Finally, after a current of water and intracellular digestion, it comes out through the osculum, an opening that they present in the upper part of their body.
Crocodile (Crocodylus spp.)
Crocodiles, including the genus Crocodylus, are one of the oldest prehistoric animals on Earth, since the first specimens appeared 250 million years agoThese are large reptiles, which can reach 6 meters in length and approximately 700 kilograms in weight. They have powerful jaws, eyes and nostrils on the top of their heads, and very thick, scaly, dry skin.
It is common to find them in the rivers, lagoons and swamps of Africa, America, Asia and Australia, although some species tolerate s alt water well. As carnivorous animals, they feed mainly on other large vertebrates such as fish, mammals and birds. Their method of hunting is to lie still and hide underwater to stalk their prey and quickly devour it when close. Despite being a great predator, it has a slow metabolism, so it does not need to be constantly feeding.
Learn about the different types of crocodiles that exist in this other article.
Other living prehistoric animals
These are other examples of animal species that have continued to inhabit our planet for thousands and millions of years:
- Hagfish
- Platypus (Ornithorhynchus anatinus)
- Sturgeon (Ascipenser spp.)
- Hula Painted Frog (Discoglossus nigriventer)
- Silver minnows (Lepisma saccharina)
Extinct prehistoric animals
Many other animal species have failed to survive extinction throughout evolution. However, we still remember them for what they represented in history, as well as for their incredible appearances. Here are some examples of extinct prehistoric animals that are therefore no longer found on Earth:
Tyrannosaurus rex (Tyrannosaurus rex)
It was a large species of bipedal reptile that inhabited the Earth more than 60 million years ago It could measure up to 13 meters long and 4 meters high and weigh between 6 and 8 tons. It was characterized by its large skull, its long and strong tail, its powerful hind limbs and small front limbs ending in two powerful claws. It inhabited the American continent where it fed on other animals, as it was a very voracious carnivorous dinosaur and used to consume all kinds of amphibians, reptiles, insects and mammals. Given its large size, it rarely became the prey of any other dinosaur itself.
As a curious fact, we can say that, despite the appearance shown in the movies, studies have shown that there is enough evidence to suspect that part of his body was covered with feathers. Find out why the dinosaurs became extinct in this other article.
Mammoth (Mammuthus spp.)
These mammals, which extinct thousands of years ago, were characterized by their large size, similar to that of an elephant, as they could reach 6 meters high and 10 long. In addition, they had dense fur that protected them from the cold and gigantic fangs curved forward that offered protection to their faces and allowed them to fight between males.
Mammoths lived in herds led by a female leader in the coldest areas of the different continents. Despite their large dimensions, they were herbivorous animals. As for its extinction, there are different theories, among them, the climates so extreme that occurred at the time and that prevented it from searching for plant material to feed, as well as hunting of these animals by humans.
Dodo (Raphus cucullatus)
The dodo was a large bird that could weigh more than 15 kilograms. Its body was stocky and had relatively small wings that prevented it from taking flight. It was also characterized by its short legs and its large head, where a very robust hook-shaped beak was located. The plumage of its body adopted grayish or brown colours, however, in the striking curly feathers on the back, white predominated.
This bird was found in the wooded areas of the Island of Mauritius, where it fed on fruits, seeds and roots, among other foods. However, it could also consume other small animals such as some fish and/or crustaceans, since it was considered an omnivorous animal.
Anisodon (Anisodon spp.)
Suspected to have lived about 15 million years ago Those belonging to this genus were huge mammals, as they weighed approximately 170 kilograms and were more than two meters long. While its forelimbs were long and ended in three large claws, the hind limbs were much shorter and more robust.
These animals were typical of the wooded areas of Europe and Asia where, in addition to finding refuge from predators, they fed on plant matter. With their long limbs they could reach the highest branches of the trees, although they also used to consume other lower plants. Possibly the drought in its habitat caused this vegetation to decrease and the large mammals to become extinct.
Megalodon (Carcharocles megalodon)
It was considered the world's largest shark, as it could weigh up to 40 tons and be 4 meters tall. In fact, in terms of its morphology, it was similar to the white shark but with much larger dimensions. It was a great predator that fed on everything that was on the way (turtles, whales, other sharks, etc.) and its extreme speed, together with its strong jaws, helped it to be very successful in its hunts.
As occurs with the other described species, the cause of extinction is not entirely known, as there are different hypotheses about the disappearance of the megalodon, such as, for example, the cooling of the seas and the oceans millions of years ago or the scarcity of food.
Other extinct prehistoric animals
If you have been wanting to know more examples of extinct prehistoric animals, here are some more prehistoric animal species that have become extinct throughout evolution:
- Sabre-toothed tiger (Smilodon spp.)
- Cave Bear (Ursus spelaeus)
- Megalania (Megalania prisca)
- Paraceratherium spp.
- Glyptodon spp.
In this video from our friends at EcologíaVerde you will be able to learn more about animals that have become extinct because of human beings and the reasons.
