Below is a collection of animals that are extinct, and that you might expect to become extinct.
Titanoboa :
The animal is big and I mean VERY VERY BIG. After the dinosaurs were declared extinct, these large animals positioned themselves as the biggest and baddest predators on earth.
They are 50 feet (15 meters) long, weighing 2,500 pounds (1.13 tons). They kill their prey by wrapping their bodies around it. Pretty scary, huh?
Dunkleosteus
Dunkleosteus lived about 360 million years ago. Dunkleosteus was a very strong fish and could grow up to 30 feet (9 meters). Its mouth that looks like a beak has a function as a weapon to bite prey, this animal is indicated as a species of cannibalistic animals or animals that like to fight over territory.
Its jaws are extremely efficient, allowing the animal to open and close them in a fraction of a millisecond.
The overall shape of dunkleosteus is still unclear, but we guess that it was only a little bit of some ancient animal that once lived after it was discovered.
Deinosuchus .
Deinosuchus means "terrible crocodile," and it lived up to its nickname. Fossils of Tyrannosaurus and other dangerous dinosaurs show bite marks from Deinosuchus. Deinosuchus was 35 feet (11 meters) long and was found in North America. In places where modern humans would be overwhelmed by a crocodile that was only a quarter of its size, Deinosuchus fought Tyrannosaurus (and won).
Arcdotus . Also known as the "short-faced bear"
A name like "short-faced bear" sounds funny. Arcdotus was a native animal of California that lived about 11,000 years ago. Almost entirely carnivorous and consuming about 35 pounds (16 kg) of meat per day, they were 50 percent larger than the largest polar bear ever recorded. A bear that was twice as tall as you are.
Megalodon
Megalodon made the great white shark look like your average goldfish (a scientist is holding the jaws of a modern shark for comparison) at 60 feet (18 meters) long. This extinct marine predator is still called the "greatest carnivore that ever lived."