Elephants and giraffes are gigantic, no doubt! Their size is enough to scare most creatures away. But, have you ever thought that such massive animals are still smaller in comparison to other few? Dinosaurs need to be the first creatures people think of when discussing prehistoric giants. However, it may come as a shock that one of the largest animals ever documented is still alive at present, despite being listed as an endangered species.

Here, you will uncover a list of the 10 largest creatures that ever existed on the Earth. Sit tight and enjoy the ride back and forth evolution!

Table of Contents

1. Ichthyosaurs

Ichthyosaurs | Image Credit – Pixabay

The early medieval remnants of a massive oceanic reptile in southwestern England have indeed been discovered. The creature, recognized as an ichthyosaur, lived approximately 205 million years ago and could grow up to 85 feet long—nearly as large as a blue whale. Ichthyosaurs were dinosaurs’ oceanic predecessors, with physiques strikingly similar to dolphins. 

Ichthyosaurs ideally appeared around 250 million years ago, at the onset of the Triassic period. And while they started along the coastlines, they ended up moving to greater depths. They were one of the most prolific living creatures in the deep ocean at their peak, filling many gaps from attacking predators to vacuum feeders. 

However, ichthyosaurs perished about 90 million years ago, nearly 25 million years before dinosaurs vanished. It is still unknown what caused the once-abundant sea reptiles to become extinct.

2. Sauropods

Sauropods | Image Credit – Flickr

Scientific researchers in Argentina have found a unique collection of bones that are now thought to have belonged to the biggest dinosaur that ever roamed the planet. Per this concept, the dinosaur was also the largest creature on land that ever survived. 

Sauropods were the dinosaurs featured in the Jurassic Park film series, with their incredibly long necks, tails, and pillar-like lower body. Titanosaurs are massive sauropods that have overshadowed the South American territories until the Cretaceous Paleogene evolutionary divergence, the asteroid strike that annihilated the vast bulk of life on Earth.

Experts claim the remnant is one of the largest sauropods ever discovered, presumably surpassing Patagotitan in dimensions based on the study of the fossil. Patagotitan mayorum, for those who are unsure, is currently thought to be the world’s largest land-based animal from history to date. 

These size projections are determined by the size of the unearthed bone fragments. As for the newly discovered titanosaur fossil, more research is necessary to understand to guesstimate its exact size because some of the fossil’s bones have yet to be revealed.

3. Colossal Squid

Into The Deep: Giant Squid Captured On Video | Video Credit – CBS Miami

The colossal squid is a humongous squid that dwells in the ocean depths around Antarctica and holds numerous global benchmarks. It is not just the largest invertebrate on the planet, but it also has the world’s most prominent eyes compared to any animal, perhaps larger than those belonging to the majestic whales. Humankind’s understanding of the colossal squid is focused on limited samples collected in the deep-sea fishing industry and mandibles discovered in the abdomens of these organisms, such as their most notable predator, the sperm whale.

It is hard to define the biology and ecology of this kind of rare organism, even something as huge as the colossal squid, with limited study prospects. The colossal squid is an extensively large deep-sea carnivore, nearing cumulative body and tentacle sizes of up to 46 feet and weights of around 1100 pounds. 

All of the largest individuals are female, as with many large mammals. They feed on small and large fish, including Patagonian toothfish and other sea creatures. Their tentacles are shrouded with suckers that have powerful, jagged hooks that they use to capture prey and combat predators.

4. Blue Whale

Blue Whale
Blue Whale | Image Credit – Todd Cravens

One of the largest mammals that have ever been on Earth does not walk but instead plunges, and no roster of the world’s largest animals would be complete without describing the gigantic Blue Whale. It is the heaviest animal ever believed to exist. 

The Blue Whale can grow to a height of up to 100 feet, though this is unusual nowadays due to excessive fishing of sea creatures. With hearts the size of small cars, these oceanic mammals can measure up to 200 tons, which is nearly 400,000 pounds and more than twice the weight of the world’s largest dinosaur. Unfortunately, the World Wildlife Fund has classified these whales as endangered.

5. Smilodon

Smilodon | Image Credit – Wikimedia Commons

Saber-toothed cats roamed the globe for 42 million years until they disappeared approximately 10,000 years ago. These ferocious felines, on the other hand, were nothing like the fuzzy bunnies you find on the comfy sofa. These cats with blade-like teeth have expanded into various groups over the last 10 million years, with the Smilodon being one of them. 

Smilodon was a huge mammal that measured 160 to 280 kg (350-620 lbs), around the exact dimensions of lions and Siberian tigers. Smilidon fatalis, Smilodon gracilis, and Smilodon populator are the three varieties of the Smilodon. The Smilodon acquired its name from the Greek words “blade” and “tooth,” which really is appropriate given that they had large, curving canines that could reach 28 cm in length. These colossal wild cats preyed on bison, antelope, and horses in the woods of North, South, and Central America.

6. Quinkana

Over time, Quinkana increased in size from 2m to 6m long and was a quick predator, and became one of the dominant species by the Pleistocene. Quinkana was one of Australia’s most potent territorial carnivores at the time, second only to Megalania. 

Quinkana first originated around 24 million years ago and died out approximately 40,000 years ago. Quinkana has no surviving relatives, but it shares one trait with Theropod dinosaurs: teeth patterns. Their teeth have been found in Eulo deposits, broadening the species’ distribution in the late Pleistocene into South West Queensland. 

Quinkana was a swift hunter due to its long forearms. Lengthy hunts exhausted its prey of mammalian species, birds, and other invertebrates. The species evolved from a species of crocodile known as mekosuchines, which is now extinct. Unlike today’s Australian crocodiles, this enormous crocodile resided on the coast. 

Water crocodiles have sharp teeth that help grasp objects but not for slashing. They grasp animals in place with their teeth until they suffocate, then swirl them into bite-sized fragments. Quinkana, on the other hand, hunted on land, so it couldn’t drown its prey. It had sharp blades in its teeth, which were used to kill and hack up animals.

7. Sivatherium

Sivatherium | Image Credit – Wikimedia Commons

Sivatherium was a giraffid genus that spanned Africa and the Indian continents. The giraffid Sivatherium giganteum is the world’s largest giraffid and perhaps the world’s largest ruminant species. The remnants of Sivatherium giganteum, dated from roughly 1,000,000 BCE, have been discovered in the Himalayan range. 

Sivatherium may have died out as recently as 8,000 years ago, as pictures of it may be found in prehistoric rock art from the Sahara desert and Central West India. It was similar in appearance to contemporary okapis, but was much larger and heavier-built, standing about 3 meters tall and weighing approximately 400–500 kg. However, a more recent estimate suggests a body mass of around 1,250 kg. This makes Sivatherium the world’s largest ruminant.

8. Paraceratherium

The Rise and Fall of the Tallest Mammal to Walk the Earth | Video Credit – PBS Eons

Paraceratherium is one of the enormous terrestrial mammals to have ever lived, measuring 17 tons and standing 16 feet tall at the neck. During the Oligocene era, these creatures wander throughout Asia and Western Europe. Paraceratherium was a gigantic hornless rhino with a long giraffe-like throat. 

They were herbivores that were tailored to eating tree trees and shrubs. They were so big that they could consume leaves on the jungle canopy, unlike most other herbivores. Their premolars were shaped to grab leaves from trees, and the nasopharyngeal region of their craniums indicated that they must have some kind of trunk. It was approximately equivalent to a Taper’s short, prehensile trunk.  It is suggested that these big mammals, like elephants, would have had difficulties maintaining their body temperature. Additionally, Paraceratherium fed primarily at dark and had large ears to release heat.

9. Megalodon

This massive, primitive representative of the shark family lived in the ocean waters approximately 25 million years ago. The megalodon was about 52 feet long and had large jaws big enough to hold contemporary rhinos. Fortunately for us (and the rhinos!), this horrific fish is thought to have died out around 1.5 million years ago.

10. Woolly Rhinoceros

Woolly Rhinoceros
Woolly Rhinoceros | Image Credit – Flickr

You’ve probably heard of the woolly mammoth, but have you heard of its hairy cousin, the woolly rhinoceros that measured three meters in length and weighed between 1,800 and 2,700 kilograms. Right from the end of the Ice Age until around 8,000 BC, the woolly rhinoceros majestically walked the planet. 

Some investigators think that climate change caused their annihilation in 10,000 BC, while others genuinely believe that ancient people overhunted the woolly rhinoceros community. Numerous prehistoric cave drawings of the hairy life form have been discovered to assert their existence further.

To Conclude

Rhino Lying on Ground Near Tree
Rhino Lying on Ground Near Tree | Image Credit – Ann Nicholls

Now that we have come to an end of our elaborate list of the 10 largest creatures ever existed on the Earth, it is time to pick your favorite. Which of these would you want to make a comeback from the history of evolution? 

(Last Updated on May 23, 2022 by Sadrish Dabadi)

Shradha Bhatta holds a Bachelors’s Degree in Social Work along with a Post-graduate degree in Project Management from Georgian College in Canada. Shradha enjoys writing on a variety of topics and takes pleasure in discovering new ideas. She likes traveling and spending time with nature. She is a very people-person who loves talking about climate change and alerting people to go green!