Six animals that used to be much bigger

Sharks

Sharks are some of the most famous predators in ocean depths. These hunters constantly patrol the seas in search of prey. While some, like the whale shark, feed on krill, others, like the great white shark, can grow up to 19 feet in length.

However, even the great white shark pales compared to its prehistoric ancestor, the megalodon. This giant lived between 23 and 3 million years ago and reached up to 65 feet in length. With such size and powerful jaws, the megalodon could hunt large animals, including whales.

Crocodiles

Crocodiles are as infamous as sharks. These reptiles dominate rivers and lakes, waiting for unsuspecting animals to approach the water before lunging in a rapid attack.

The largest crocodiles are saltwater crocodiles, which range from 12 to 18 feet in length. But this is nothing compared to the prehistoric predator Deinosuchus, which lived between 82 and 73 million years ago.

This enormous reptile, which existed alongside dinosaurs, reached a length of 35 feet and posed a threat even to the largest land animals.

Millipedes

Millipedes may be small, but they instill fear in many people. These creatures are typically only a few inches long, though the largest species can reach up to 16 inches. They use their many legs to navigate forested areas, feeding on plants and fungi, making them almost harmless to animals.

However, their ancestors were entirely different. Arthropleura was a massive millipede, growing 6 to 7 feet long, with virtually no natural predators. It lived during the Carboniferous period, between 345 and 290 million years ago, and may have been both herbivorous and omnivorous, given the wide range of food available in its environment.

Sloths

Sloths are slow and inconspicuous animals that live primarily in trees. They feast on leaves and rarely come down to the ground, helping them avoid danger. Though their large claws may look intimidating, they pose little threat to humans, as sloths are quite small, around 2 feet in length.

Their prehistoric relatives, however, were a stark contrast to modern sloths. These giant ground sloths reached 10 feet in length and weighed over 22,000 pounds. Unlike today's tree-dwelling sloths, which hide from predators, ground sloths do not need such protection.

Birds

Many scientists believe that birds are descendants of dinosaurs. Although significantly smaller, their body structure and feeding habits indicate a close relationship.

Among their ancestors were terror birds, which lived between 9 and 4 million years ago. These agile predators stood up to 10 feet tall. While they couldn't fly due to their small wings, their massive beaks and powerful legs allowed them to hunt almost any land prey.

Snakes

Snakes are among the most diverse reptiles on the planet. Their sizes range from just a few inches to over 20 feet, and their diet consists of any animal that can fit into their jaws. Smaller snakes usually feed on rats and insects, while larger species can hunt deer, sheep, or capybaras.

Prehistoric snakes are even more impressive. The largest known is Titanoboa cerrejonensis, which reached a length of 42 feet — more than twice the size of the largest modern snakes. Its size allowed it to constrict and consume most animals of its time. Titanoboa lived between 66 and 56 million years ago and likely hunted crocodiles, fish, and turtles. It may have even eaten other snakes.

Earlier, we published a list of real sea monsters that are hard to believe exist.

Sources: List Verse and Wikipedia.