Megafauna simply means large animals. These are found in all the terrestrial regions of the world. The average weighing threshold for megafauna is over 40 kgs or over a tonne. However, in practice, land animals larger than a human and are not domesticated constitutes megafauna. It is used for the largest extant and extinct terrestrial wild animals. For eg., Giraffes, elephants, rhinoceros, hippopotamus, etc.
The huge plant and animal species with the widespread popular appeal due to their attractive appearance are known as charismatic megafauna. They can be identified easily. Giant panda, lion, humpback whale, grey wolf, bald eagle, etc. some of the charismatic megafauna in the world.
These animals are generally used by environmental activists in conservation campaigns because they can attract the public. Most of the organizations use these animals as their logos. For eg., The World Wildlife Fund uses Panda in their logo.
There are a large number of extinct megafauna. In an era when there were no human settlements, the animals freely evolved. Human interference led to the extinction of the megafauna. Early humans would have hunted these large animals to feed their families which led to the reduction in their number. Also, the large predators would have been killed to protect themselves from attack. The changing climate and atmosphere was another reason which led to their extinction over the years. There were sharks 50 feet long, wild otters as huge as wolves, and many more. Following are the examples of some prominent megafauna that existed millions of years ago.
Also read: Evidence of Evolution
These mammals became extinct 10,000 years ago. The glyptodons were the size of a VW beetle and were a well-armoured body with sharp spikes to protect themselves from predators. But they could not pull their head inside the hard turtle-like shell and depended upon their armoured body for defence.
These were known to be the largest flying birds. It could grow to 24 feet which is twice the size of the largest bird, Andean condor, today. Their heavy body would have made it difficult to take off while flying, and so they are believed to have built their homes in the mountains. The bird was a scavenger and fed on the dead and decaying matter.
It is one of the largest known mammals that have lived on the earth to date. It existed 25 million years ago and is believed to be 20 feet tall. They are believed to have fed on grass. Its appearance is not clear because of fewer fossil records available to the archaeological department.
These were 23 feet long and weighed 4000 pounds. It lived in Southern Australia during the Pleistocene era and is believed to be the largest venomous creature at that time. They fed on other large animals.
These megafaunas appeared during the Pleistocene epoch. The giant birds, mammals, and reptiles in the late Pleistocene age got extinct in the Quaternary Extinction Event. Various factors such as altered habitat condition, climate change, disease, and the breakdown of food webs are considered responsible for the extinction of megafauna in this era.
The recent researches have come up with the overkill hypothesis responsible for the extinction. According to this hypothesis, human colonization was the main reason for the extinction of these animals in the Pleistocene age. Humans started hunting animals for food and to protect themselves from any harm. Slowly the animals became extinct.
Also read: Extinction
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