Terrible turtles

　　
　　Let's start with the basics. There are two types of snapping turtle: the Common Snapping Turtle (Chelydra serpentina) and the Alligator Snapping Turtle (Macrochelys temminckii). A common snapper has a smoother shell than an alligator snapper's, which has three distinct spiky ridges. Don't be fooled by common snapper hatchlings, however. They have ridged shells at birth that even out over time. The alligator snapper has a more triangular head with little bumps that look like eyelashes around the eye. Generally, the alligator snapper looks more prehistoric than the common snapper. Can you tell these two apart? (Source)
2. Common Snapping Turtles are an Ancient Species

　　People say turtles are slow, but snapping turtles might say that humans are slow! The modern snapping turtle evolved over 40 million years ago, while anatomically modern humans emerged only 200,000 years ago. Snapping turtles hung out with dinosaurs, but they're not closely related at all. Birds have more in common with dinosaurs than snapping turtles do. Source.