Dot Earth has an extremely sad story about two species that are now officially considered extinct. These are not some obscure insect or microbe, but rather the Caribbean Monk Seal and Yangtze River Dolphin. Specifically in the case of the dolphin, a letter from government biologist Robert L. Pitman points out that this Chinese water mammal was wiped out not due to being hunted for food or some other need, but simply because of human lifestyle. The following quote is eye-opening and saddening:
Sorry if I got a little emotional here, but the disappearance of an entire family of mammals is an inestimable loss for China and for the world. I think this is a big deal and possibly a turning point for the history of our planet. We are bulldozing the Garden of Eden, and the first large animal has fallen.