The ancient and intimidating frilled shark is at least 150 million years old, meaning it swam the oceans at the same time some of the Jurassic period's most famous dinosaurs, such as the stegosaurus, still roamed the Earth.
One of the most famous remnants of an ancient, reptilian Earth, is the Komodo dragon of Indonesia. Today, they are the largest lizards on Earth, and have been around for nearly four million years.
The shoebill stork is a huge bird with a strikingly unique profile. The massive beaks of these birds help them hunt larger prey than most of their stork and waterbird relatives.
While there are hardly more than 1,000 Bactrian camels left on Earth, they have proven to be one of the most resilient animals on Earth for the past two million years.
The platypus's close relative, which looks like a cross between a porcupine and a hedgehog, is at least 110 million years old, making it the oldest surviving species of mammal in the world.
Native to the upper regions of North America, musk oxen have been around for nearly 200,000 years, making them nearly as old as modern humans.
Once considered holy by the Incan Empire of South America, vicuñas are the still-living ancestors of modern llamas. Vicuñas have roamed the lowlands and highlands of Patagonia for at least 130,000 years.
One of the most ancient inhabitants of Earth that is still with us is the chambered nautilus, a seafaring cephalopod that has been around for 500 million years.
Babirusa are distinct from other hogs, and animals in general, in that their tusks, meant for protection and combat, will eventually grow backwards to the point of piercing their own skull and killing them.