Megafauna Of The Past

Earth is a playground for evolution to play, and time has tested the biggest of animals. With time, we’ve seen many faunas evolve into the one’s we know today. From elephants to blue whales, the modern world is blessed with a mega diversity of flora and fauna but the past had something which has been encased in fossils that shows just how intriguing the prehistoric animals were and how they were vital to their ecosystem.

Picture Credit: Live Science

With the megafauna around the modern world mentioned above, it’s only natural to talk about them but what makes them unique? They are vital to our ecosystem as they work as ecosystem engineers. The term ecosystem engineers are organisms that modify the environment around them to suit their needs in turn making new habitats or changing existing ones. These animals have a huge impact on the species richness of the ecosystems they thrive in. I’ll be talking about some mega-fauna found back in the day and do a comparison alongside the modern fauna to see just how they change the ecosystem around them.

Ground Sloth (Megatherium americanum)

Picture Credit: dino animal

Megatherium or Ground Sloth as researchers call them were huge sloths that lived in South America from Pleistocene to Holocene. They were as large as elephants and could have exceeded some species of mammoths. They were around 6 meters (20 feet tall) and weighed around 4 tonnes. They had a robust skeleton with a huge pelvic girdle and a huge muscular tail with strong hindlimbs it allowed them to feed on heights. Their strong legs along with their muscular tail made for a tripod which allowed them to reach heights that other mammals couldn't reach and use their claws were used to tear branches and eat the vegetation on the trees.

Comparison With Modern Relatives

Well, when it comes to comparing Megatherium americanum to the modern sloths their size is one of the main factors that prove that not all large organisms survive. While megatherium had a population decline especially due to the Great American Interchange. The rise in competition along with the rise in temperatures caused the extinction of these giants ultimately allowing the other sloth species to thrive.

Picture Credit: Wikipedia

Early hominids also hunted the ground sloths down to extinction. Ground sloths survived in the Caribbean but they also went extinct as the early hominids finally inhabited the Antilles.

Killer Kangaroos (Proplepus oscillans and Balbaroo fangaroo)

Picture Credit: Researchgate

Well, kangaroos are probably the most studied marsupials in the world, they represent a group of animals that are well documented with their ecology and ethology. But what if tell you that the kangaroos we see today had fangs and would feast on meat. Well, if you’ve been around in the Late Oligocene to the Early Miocene in Australia, it would be true. Proplepus oscillian and Balbaroo fangaroo were species of Kangaroos who would feast on other smaller animals and vegetation making them omnivores, they weighed around 5-10 kgs but it’s a debate that’s still ongoing.

Picture Credit: wakaleo.net

One of the most striking and intriguing features of these animals is their jaw structure and teeth. As they have teeth that are technically made for chewing and grinding, they have canine teeth made for tearing flesh.

Comparison With Modern Relatives

Picture Credit: ThoughtCo

The sole difference between their diet and the habitat they used to thrive in. The 4 species of Kangaroos that live today are seen in various habitats from woodlands, plains, Savannah and Forests. While the carnivorous kangaroos that were found in River sleigh formations in Northern Queensland show that these carnivorous macropods must have inhabited lush forests rather than the Savannahs that the modern-day kangaroos live in today.

Paraceratherium (Near Horned Rhinos)

Picture Credit: dinopedia fandom

Also known as the near hornless beast, it was one of the largest land mammals of its time, Paraceratherium was one of the relatives of modern-day Rhinos and Elephants. Towering at 5.2 metres ( 17 ft) shoulder length and 8.4 metres ( 28 feet) tall and weighed around 15 to 20 tonnes. This intriguing cousin of the rhinos lived in areas of present-day Eurasia. They lived from The Early Oligocene to the Late Oligocene epoch around 34 to 23 million years ago. Due to their size, they were less predated on and would’ve had a slow reproduction rate just like modern-day elephants.

Comparison With Modern Relatives

As mentioned above, Paraceratherium was related to modern-day elephants and rhinos, they have quite a taxonomical resemblance with elephants especially their trunk-like nose and tusk-like teeth. They share the same thick hide as Rhinos. A big herbivore, they were probably ecosystem engineers of their domain and moulded the environment which benefited other animal communities that lived amongst them.

Ambulocetus Natans

Picture Credit: Newscientist

Whales of today, are found in various shapes and sizes. From predators to pleasant baleen swimmers who would feast on plankton and krill. But what if the whales of today would hunt on land and water, then Ambulocetus Natans would have fit the billing. One of the most vicious predators of its time, they were found in shallow waters of India which at the time was a mangrove and marshy area around 47 to 46 million years ago. They were known to be hunting like crocodiles waiting near shores and ambush their prey. Weighing around 300 kgs and measuring 10 ft in lenght. It would hunt on big prey and use its jaws for crushing.

Comparison With Modern Relatives

Picture Credit: Defenders.org

There are certain similarities between Ambulocetus and Modern Whales and surprisingly even Crocodiles and Alligators. They have morphological and taxonomical similarities which bring alot of evidences on their evolution along with their relationship with another group of animals that are known as Hippos.

Evolution has brought us such marvellous creatures that being encased in fossils and buried for millions of years makes understanding the animals quite fascinating and vital as to understanding their role in their ecosystem and how they helped other organisms around them.

If you like what I write then please like and share this article with your friends and fellow animals enthusiasts who wish to learn about such animals. Stay safe and take it easy in such unprecedented times👻☺️.

To know more about me follow my Instagram: beardedtarzaan

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Abhidyu Ajila

Abhidyu Ajila

A zoology student who talks animals, conservation, evolution and geography