Extinct and current megafauna (with examples)

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Charles McCarthy

The megafauna They are those animals that have a large size, such as dinosaurs, elephants, sharks, mammoths, etc. The word derives from the composition of two Latin words that literally mean “Big animal".

Most of the megafauna on earth became extinct millions of years ago due to the intense geographical and climatic changes that the planet underwent at that time. It is believed that many of these changes were the product of a meteorite impact in what is now Oceania, although other theories suggest that it occurred in the Yucatan peninsula, in Mexico..

Camarasaurus, Brachiosaurus, Giraffatitan, Euhelopus. Source: Богданов [email protected] / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/)

The theories that are handled in the scientific world propose that the impact of this meteorite could have caused accelerated changes, both in the climatic conditions and in the geological and maritime conditions of our planet.

Experts today compare those changes millions of years ago with those that the human species is causing and that today, together, we call "climate change".

In 1991, paleontologist J. Stuart suggested that the classification of animals as "megafauna" could be considered if the animal had a weight equal to or greater than 40 kilograms. However, modern zoologists use different criteria such as:

- Body weight over 100 kg

- Body length greater than 2 meters

According to these parameters, many of the species of mammals, reptiles, fish and birds can be considered as "megafauna", which is often commercially exploited in circuses, zoos, etc..

Article index

  • 1 Extinct megafauna
    • 1.1 The dinosaurs
    • 1.2 The mammoths
    • 1.3 Giant fish
  • 2 Examples of current megafauna species
    • 2.1 Australian megafauna
    • 2.2 European megafauna
    • 2.3 American megafauna
    • 2.4 Asian megafauna
    • 2.5 African megafauna
  • 3 References

Extinct megafauna

Archaeologists believe that the last great mass extinction event of many of the animal species classified as “megafauna” was the product of the great ecological and environmental changes at the end of the last great glaciation or ice age, in the Pleistocene epoch..

Since then, the large animals (megafauna) that have become extinct have done well due to "selective pressures" or the emergence of sudden changes in the environment they inhabited, to which they could not adapt and ended up becoming extinct..

Many of these changes or current selective pressures have been caused by the human species in natural ecosystems, through poaching and / or sports, through deforestation, pollution of water, air and soils, due to warming global, etc.

Among the extinct megafauna species, several different animal species stand out, classified into groups of animals that are widely known such as dinosaurs, mammoths or giant fish species..

The dinosaurs

Most of the dinosaur fossils that archaeologists have found correspond to large animals. Many of these were between 5 and 20 meters in length and weighed several tons..

The most accepted theory establishes that these gigantic and apparently majestic animals saw their end thanks to the great changes caused on the planet by the impact of a meteorite, millions of years ago.

Of these "reptiles" there were many different species, which are widely known from fossil records. However, the most prominent are:

- The tyrannosaurus rex (Tyrannosaurus rex)

Hypothetical appearance of the Tyrannosaurus rex 

It was a fearsome carnivore that inhabited the earth more than 68 million years ago, specifically in what is now North America. This "mega-animal" measured between 10 and 12 meters in length and weighed around 8 tons. It fed on other species of dinosaurs.

- The pterodactyl (Pterodactylus. sp)

Reconstruction of a pterodactyl. Source: Matthew P. Martyniuk / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

They were flying and carnivorous dinosaurs, which fed on fish, young of other dinosaurs and other smaller animals. Its fossil remains have been found on the European and African continent. Its maximum length could reach up to 2 meters and its weight exceed 50 kg.

- Brachiosaurus (Brachiosaurus altithorax)

Hypothetical appearance of the brachiosaurus

This was, perhaps, the largest land animal that has ever existed on the face of planet earth. It was a herbivorous animal that measured about 26 meters in length and weighed more than 35 tons..

Only the length between the torso and the head was greater than 10 meters. Its fossils have been found mainly in the northern part of the American continent..

Mammoths

Hypothetical appearance of a mammoth

They belonged to a genus of the elephant family (Elephantidae) and inhabited the earth for approximately 5 million years. It is thought that it was one of the few families that became extinct en masse after the last great ice age on planet earth..

Mammoths became extinct about 3,500 years ago, so they coexisted with several species of humans (of the genus Homo) from prehistory.

Mammoth fossils have been found on almost every continent on earth. They were herbivorous animals, with an average length of 9 meters and a weight of 10 tons..

Giant fish

Photograph of a fossilized tooth of a megalodon

Fish were perhaps the first animals to reach the dimensions established as criteria for the classification of megafauna, since the oceans correspond to the place where life is believed to have originated and the first places where living organisms began to differentiate into different species.

There were many species of fish that can be classified as megafauna. However, there is one in particular that is widely recognized by almost everyone: the megalodon (Carcharocles megalodon).

The megalodon was an animal very similar to the white shark. Lived more than 10 million years ago in the oceans.

Connoisseurs of the matter estimate that its length may have been greater than 20 meters and its weight varied between 20 and 50 tons. It was, surely, the greatest predator of aquatic ecosystems during the Cenozoic and Pliocene.

Examples of current megafauna species

The current megafauna, with sizes considerably smaller than the animals we have just described, consists of a group of large wild animals, which generally do not have predators in the ecosystems where they inhabit..

They are all over 2 meters tall and weigh much more than 40 kg and it is important to note that many, if not all, are currently in danger of extinction..

There are species considered megafauna on all the continents of planet earth, but these are rare and difficult to observe. Here are some examples of the main “big animals” in the different continental territories:

Australian megafauna

The great majority of the Australian megafauna that inhabited the continent after the age of the dinosaurs became extinct with the arrival of the human species on the great island; it is not known with certainty whether the direct or indirect product of anthropic action (of the human being).

However, there are currently some animals that are classified as megafauna, among them three species of kangaroos, some species of reptiles and several species of fish stand out..

- Gray kangaroo or giant kangaroo (Macropus giganteus)

Gray Kangaroo Photography

They are marsupials that inhabit the south and east of Australia. They feed on herbs and reach a length of up to 2 m and a weight close to 70 kg. They have very powerful hind legs, with which they can run at speeds of up to 56 km / h.

- Tiger shark (Galeocerdo cuvier)

Photograph of a tiger shark (Source: Albert Kok / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0) via Wikimedia Commons)

It is a species of shark that lives on the temperate coasts of Australia; It feeds on fish, rays, squid, and other aquatic animals. It can reach up to 5 m in length and weigh more than a ton.

The common name of the species is due to the fact that on the surface of its skin it has a pattern that resembles the pattern that the cats of the Asian continent have in their fur..

- Australian giant monitor (Varanus giganteus)

Photograph of the Australian monitor lizard kept in captivity at the Zürich Zoo (Source: Albinfo / CC0, via Wikimedia Commons)

It is a species of reptile endemic to Australia that reaches 2 meters in length and can weigh up to 25 kg. Feeds on the eggs of birds, reptiles, young small mammals, and sometimes carrion.

European megafauna

As in Australia, much of the megafauna of this continent became extinct with the establishment of humans in the place. However, there are still some different animal species that can be considered as megafauna..

In the group of large European animals, symbolic animals for the continent such as the European Bison (Bison bonasus), the red deer (Cervus elaphus), The grizzly (Ursus arctos), the gray seal (Halichoerus grypus), the griffon vulture (Gyps fulvus), etc.

- European bison (Bison bonasus)

Photograph of a European Bison (Image by and-kulak at www.pixabay.com)

It is the largest mammal that lives in Europe. Their fur is dark brown in color and they are forest-dwelling herbivores. They are approximately 3 m in length and weigh between 50 and 90 kg. European bison are considered one of the most threatened species in all of Europe.

- Red Deer (Cervus elaphus)

Photograph of a red deer (Image by Manfred Antranias Zimmer at www.pixabay.com)

It is distributed mainly in the northern hemisphere of the European continent. The females live in herds, while the males roam alone. They are herbivorous animals of about 2 m in length and weighing about 200 kg..

- Grizzly (Ursus arctos)

Photograph of a brown bear / grizzly (Image by brigachtal at www.pixabay.com)

They inhabit the European forests, they feed on many different things: small vertebrates, insects, shoots from the ground, carrion and fish. They can measure up to 2 meters in length and weigh up to 400 kg. They are one of the land animals with the strongest limbs.

American megafauna

The American continent, along with Africa and Asia, is perhaps one of the continents that has the greatest amount of megafauna. Some of the most representative animals are the bald eagle, the Andean condor, the black bear, the jaguar, the puma and others..

- Jaguar (Panthera onca)

Photograph of a jaguar

It is a carnivorous feline typical of the tropical forests; It inhabits from the southern tip of North America to central South America. In some places it can reach up to 2 meters in length and weigh almost 150 kg.

- Black bearUrsus americanus)

Photograph of a black bear

It is the most common species of bear in America. It is found in the northern part of the American continent and can measure more than 2 m in length and weigh more than 280 kg. Its diet is very varied, to such an extent that many experts consider it omnivore, although it mainly feeds on sprouts, nuts, insects and salmon.

- Andean condor (Vultur gryphus)

Photograph of an Andean Condor

It inhabits almost the entire Andean mountain range of South America. It is a large bird that feeds on carrion (it is the largest bird on the planet). It can reach up to 3 meters in length and weigh about 20 kg. It is in serious danger of extinction.

Asian megafauna

In Asia we find species such as the tiger, the panda, the snow leopard, some species of elephants, the Komodo dragon, among others..

- Bengal tiger (Panthera tigris tigris)

Photograph of a bengal tiger

These big cats, well known to society, inhabit the jungles of India and Bangladesh. They are carnivorous animals that feed on birds, mammals, and fish. They can be up to 3 meters long and weigh more than 200 kilograms.

- Panda (Ailuropoda melanoleuca)

Photograph of a panda bear

This huge mammal only lives in southwestern China; it is one of the most endangered animals. It is herbivorous and feeds almost exclusively on bamboo leaves. Adult pandas can grow up to 2 m in length and weigh more than 150 kg.

- Asian elephant (Elephas maximus)

Photograph of an Asian Elephant

It is the mammal that reaches the largest size in the Asian continent, since it can reach 4 meters in length and weigh up to 5 tons.

Asian elephants are herbivorous animals, whose distribution includes Indonesia and southern China. The current populations of this large mammal are very small and are, of course, in danger of disappearance.

African megafauna

The African megafauna is known worldwide, the terrestrial animals of this continent are especially large and majestic, if we compare them with the animals of other continents.

Among the megafauna of the African continent are lions, cheetahs, ostriches, hippos, rhinos, elephants, giraffes, the Nile crocodile, gorillas, among many others..

- Lions (Panthera leo)

Photograph of a male lion

They are large carnivorous felines, with a marked sexual dimorphism between the male and the female: which the male has a long mane around the neck, meanwhile the female has a uniform coat..

They live in sub-Saharan Africa, being able to reach 3 meters in length and up to 400 kg in weight. They hunt their prey in herds, usually feeding on zebras, gazelles or bison that live in the African plains.

- Gorillas (Gorilla. sp)

Photograph of a Gorilla

The gorilla is one of the mammals that is most closely related to the human species. It inhabits the treetops of the forests of central Africa. It is a herbivorous animal and can reach 2 meters in length and more than 200 kg in weight..

- Ostriches (Struthio camelus)

Photograph of a group of ostriches

It is one of the largest birds in the world. It is characterized by not being able to fly and by reaching high speeds while running. It inhabits a large part of the African continent. They can generally be 3 meters long and weigh 200 kg. They are herbivorous animals.

References

  1. Fariña, R. A., Vizcaíno, S. F., & De Iuliis, G. (2013). Megafauna: giant beasts of pleistocene South America. Indiana University Press.
  2. Galetti, M., Moleón, M., Jordano, P., Pires, M. M., Guimaraes Jr, P. R., Pape, T.,… & de Mattos, J. S. (2018). Ecological and evolutionary legacy of megafauna extinctions. Biological Reviews, 93 (2), 845-862
  3. Malhi, Y., Doughty, C. E., Galetti, M., Smith, F. A., Svenning, J. C., & Terborgh, J. W. (2016). Megafauna and ecosystem function from the Pleistocene to the Anthropocene. Proceedings of the National Academy of Sciences, 113 (4), 838-846.
  4. Ripple, W. J., Chapron, G., López-Bao, J. V., Durant, S. M., Macdonald, D. W., Lindsey, P. A.,… & Corlett, R. T. (2016). Saving the world's terrestrial megafauna. Bioscience, 66 (10), 807-812.
  5. Stuart, A. J. (1991). Mammalian extinctions in the Late Pleistocene of northern Eurasia and North America. Biological Reviews, 66 (4), 453-562.

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