Outsized fleas plagued biggest land animals
Dealing with asteroids, Tyrannosaurs, and shoving enough food in their mouths was bad enough, but the world's biggest-ever land animals also had to deal with fleas. Fleas ten times the size of modern ones, equipped with long claws to hold onto the edges of scales while their built-in hypodermicc needles poked the skin between to suck out blood.
COMMENT: My daughter Corey follows Buddhism and thinks all life is sacred. Well, perhaps it is sacred, but that doesn't mean it's all necessary. We modern creatures are perfectly happy to do without these mega-fleas.