I guess the egg always splits into four embryos after fertilization. I found their Wikipedia page surprisingly fascinating. They also can't roll into a ball, but CAN use their intestine like a swim bladder, wtf is going with these little guys?
many species of conifer require fire to propagate - the high heat releases the seeds from their protective enclosure. this is why forest fires are beneficial to some forest environments
Dogs don't come from wolves, but dogs and wolves have a common ancestor, a wolf population that went extinct and differs from dogs and modern wolves. They still are the same species to biology standards (even with the fact of crazy breeding happening), but psychologically and which is the root of the split, they are very different and the more important change. Wolf are predisposed to being shy and hate anything novel once they are adults, dogs are very transient socially and very curious. Both being their nature how they have survived.
Tardigrades (water bears) are well known to be extremophiles which survive pretty much anything. But they actually contain a unique protein called Dsup, for damage suppressor, which can increase the resistance DNA to damage by binding to it and acting as a barrier from ionizing radiation for example. If it can be proved safe for humans it could help with deep-space missions and help humanity travel further!
Certain bird species, like pigeons and parrots, will release their tail feathers when they get caught by a predator. This way they can escape, leaving the predator with a mouth full of feathers. Sometimes it's called fright moult.