Even though dinosaurs are often considered huge beasts, many other species—both reptiles and mammals—attained gigantic sizes well after the demise of the dinosaurs. Extinction of non-avian dinosaurs did not mark the end of gigantism. As time went by and ecosystems changed, impressive-sized animals followed.
Below are ten enormous creatures that dominated the Earth after the age of the dinosaurs:
1. Barylambda
Millions of years after the dinosaurs are gone, mammals began to grow bigger, and along with that stood pantodonts, one of which was Barylambda. Barylambda was a North American 50-60 million years ago, herbivore, and weighed around eight feet long and 1,000 pounds. Barylambda was one of the largest mammals in its environment, so paleontologists were led to determine when mammals began to evolve into larger body sizes.
2. Titanoboa
Few years after the dino extinction, the earth faced one of its biggest snakes in the form of Titanoboa on earth – a gigantic snake, measuring more than 40 feet long with an estimated weight around 2,000 pounds. It was living in what is now Colombia. The snake thrived under tropical conditions; it possibly preyed on fish instead of a top predator since it was so big in size.
3. Barinasuchus
Barinasuchus was a land-based crocodile living from 15 to 55 million years ago in South America. Over 20 feet in length and weighing over 3,000 pounds, this massive predator had all the appearances of a cross between a super-crocodile and a dinosaur. The creature was indeed an active land hunter, and one of the largest known crocodiles ever to have walked the earth.
4. Paraceratherium
One of the biggest land mammals is known as Paraceratherium. It roamed parts of Eurasia 23 to 34 million years ago. This giant rhino was over 15 feet tall at the shoulder, had a six feet long neck, and weighed around 33,000 pounds. Such vast size saved the animal from the attacks of its predators, and remains of the creature were present along with evidence of big crocodile bites.
5. Megalania
Megalania, an ice age monitor lizard of Australia, can reach 26 feet in length. While estimates are shaky, it is obviously one of the few powerful predators at the least. The curved pointed teeth may have also been venomous, as is the saliva of the Komodo dragon which, upon being bitten, will immediately incapacitate before dying. One of the largest and most fearsome features of Megalania would rank it with the top predators of its environment.
Read Also: The Giants After Dinosaurs: Extinct Creatures and Their Modern Relatives
6. Elephant Bird (Aepyornis maximus)
Madagascar once supported the world’s biggest flying bird: Aepyornis maximus stood nearly ten feet tall and weighed more than 1,000 pounds. Its eggs, which made up to half a ton in weight, could weigh up to 20 pounds. Although extinct for over a thousand years, the most probable causes of its extinction were human activities coupled with climatic changes.
7. Pelagornis sandersi
This is the largest known flying bird that lived about 25 million years ago in what is now South Carolina. The bird measured almost 21 feet long and looked, indeed, like a giant albatross, but the bird was well equipped with “pseudo-teeth” to catch its prey while hunting over the ancient seas during long-distance glides.
8. Megalodon (Otodus megalodon)
Otodus megalodon is called the biggest predatory shark that has ever lived. This monster measured between 34 and 52 feet in length, with its food consisting mainly of marine mammals such as whales. Its body size can be attributed to its evolutionary traits, including fast growth rates, a unique mode of embryonic development wherein the embryos at different levels of maturity consumed smaller ones inside the womb.
9. Steppe Mammoth (Mammuthus trogontherii)
The steppe mammoth, is the extinct ancestor to the well-known woolly mammoth, which is held to be the largest land-living mammal found from the given period. These gigantic beings survived in Eurasia from 200,000 years back to 1.8 million years ago and were measured to stand up to 15 feet tall at the shoulder level. Steppe mammoths were pivotal to the development of mammoths and mammoths that later went on to survive the Ice Age.
10. Blue Whale
If the blue whale were alive today, it would be the biggest animal that ever existed, even greater than any known dinosaur. It can measure 98 feet or weigh as much as 200 tons; this makes the blue whale one of the wonders of evolution among living organisms. Mass alone is impressive enough, but these whales evolved about 1.5 million years ago-probably some of the latest large mammals to evolve-proof that life today continues to adapt into impressive sizes.
These monsters remind us that closing the era of the dinosaurs marked the perpetuation of life on Earth and further towards even monstrous dimensions.
Why did they evolve?
These huge animals emerged subsequent to the tectonic eruption of non-avian dinosaurs. These come out from ecological opportunities, aside from environmental factors. Here are the principal causes for which this type of huge animals emerged:
Vacant Niche
The extinction of the dinosaurs, caused by an asteroid impact about 66 million years ago, killed so many large contenders and left giant ecological niches. Large ecological niches include top predators and large herbivores. In the absence of the dinosaurs, mammals, reptiles, and birds had opportunities to develop into those ecological niches. Similarly, in the absence of large predators and large herbivores, new species could grow bigger in the future.
Abundant Resources
There were fewer massive animals, which left more abundance of food and space. Many of the plants and smaller animals survived well in the new habitat, making a good source of food for bigger species to come forward. This helped animals become enormous in sizes, like Barylambda and Paraceratherium, which had an enormous amount of plant life to feed on to support their enormous bodies.
Climate and Environmental Conditions
At some post-dinosaur periods, Earth’s climate became warmer and favored larger growth in cold-blooded animals, such as reptiles. For instance, Titanoboa thrived in the warm, swampy conditions that existed in prehistoric Colombia. This is because warm temperatures allow reptiles, which regulate their body temperatures with external heat, to grow bigger and become active for a longer period.
Predatory and Survival Advantages
With size came both offensive and defensive benefits. For predators like Megalania and Otodus megalodon, size afforded the ability to dominate and overcome prey. For herbivores like Paraceratherium, size provided protection against predators, as very few animals could challenge such gargantuan creatures. Successful species are those with few natural enemies, and being larger yields more success in survival and reproduction.
Evolutionary Forces
In a struggle for food and mates or territories, competing against species that survived often provided driving forces for evolutionary change that could favor bigger body sizes. Animals that were larger and better able to defend themselves and compete over available resources, or in those situations that exploited all available resources, would therefore have a higher chance of survival and then a greater opportunity to pass on such genes.
This is evident in species such as Pelagornis sandersi, where they evolved large wings that would allow them to cover massive distances above water to garner as much food as possible.
Gigantothermy
Being large helped regulate body temperature because large animals lose heat more slowly, and hence they can survive in such environments regarding that concept called gigantothermy. Such was the case for animals like Barinasuchus and Steppe mammoths.
That is to say, these gargantuan creatures started to appear owing to the arising ecological niches and favorable climate conditions together with the selective advantages large size would provide toward survival and competition. The extinction of the dinosaurs created a world overflowing with opportunity, new giants succeeded in arising and thriv-ing.
Conclusion
And here’s how it all ends-the tale of the demise of non-avian dinosaurs. How can the exit of a species result in the end of a domination in nature? Gigantism did not vanish off the face of the Earth but instead provided an opportunity for other species to grow into impressive giants. And with ecological niches open, abundant resources, favorable environmental conditions, and evolutionary forces pushing them through their growth, came Titanoboa, Paraceratherium, and Megalodon to fill in the shoes of giant predators and herbivores.
The enormous size provided the best adaptations of these animals in terms of hunting, survival, and reproduction for their respective ecosystems. Even today, animals such as the blue whale remind us that life continues to adapt and evolve sometimes in colossal dimensions giving testament to the tenacity and diversity of life on Earth.
