When we think of reptiles, we often think of geckos and chameleons—but did you know the amphibious creatures we see today are actually predecessors of dinosaurs? With more than 8,240 reptilian species spread out across six continents, these time-tested animals first emerged more than 200 million years ago when Earth still contained Pangea. Why only six continents? Because reptiles and amphibians are cold-blooded, they don't generate their own heat. This means they rely on the warmth of external sources, like the sun, to help keep them alive. In Antarctica, the temperatures reptiles need to stay alive are virtually unreachable, marking the continent the only one without amphibious species. Interestingly, despite the staggering number of species, there are only four major reptile groups: turtles, crocodilians, squamata and tuataras.
These creatures' ancestral lineage may predate the dinosaurs, but with the popularity of reptilian pets today you may never know it. Reptiles and amphibians are often sold as house pets, although somewhat controversially depending on the species. Check out this playlist to get expert testimony on best pet care practices, up-close footage and in-depth historical context into the lives of these cold-blooded critters.