Some kinds of animals that are still around today were in existence millions of years ago during the time of the dinosaur.

One of these survivors is the crocodile, which has been around for about 100 million years. Today’s crocodiles can grow to a length of 20 feet and weigh about a ton. Their prehistoric ancestors were about two-and-a-half times the size of today’s animals.

Another survivor from the past is the Galapagos tortoise, whose history goes back around 200 million years. The tortoise of today has not evolved much over the last 200 million years; it looks about the same now as it did way back then. The oldest survivor from prehistoric times is, can you believe it, the cockroach. Cockroaches have been able to stick around for more than 250 million years. The main reason for their incredible endurance is their ability to live in all kinds of conditions and survive on all kinds of food.