Short answer: no. Long answer: noooooooooooo. The linked site has some interesting theories dotted here and there, such as the suggestion that the Labrador Duck may have been a hybrid of Steller's Eider and Common Eider, and reports on a few little-known hybrids which have been historically proven. However, a *lot* of the material on the site can best be described as batshit insane - most notably assertions that a deformed cow born in Indonesia was a cattle x dog hybrid, and a lengthy treatise on why Homo sapiens is likely to be a natural hybrid of Pan troglodytes and Sus scrofa.
Re the Labrador Duck. Glen Chilton in his book The Curse of the Labrador Duck, he mentions that the genetic sequence of the duck had been recorded and was used to determine that all of the eggs reported to be labrodor duck eggs were in fact not. Therefor I would think that if the duck had been a hybrid it would have been known by then. As for the quagga I seriously doubt it.
Oh, I don't think the theory is likely to be accurate - I just think it is quite an interesting hypothesis, and a lot more realistic than positing a primate x artiodactyl hybridisation event
Zebra+horse=zorse Donkey+zebra=zonkey Female horse+male donkey=mule Male horse+female donkey=hinney quaggas are a sub species of zebra
