How? Because their eyes are not identical?Better example.
Lets say there are 1,000,000 species, all the most complex animal that live or have lived, that share the "classic traits".
We have determine they do not have a common ancestor.
You said it, I didn't.
You are missing my point...shouldn't all animals with what we would consider "classic" animal traits...two eyes, two ears, one mouth, heart, pulmonary system, digestive system, circulatory system etc...share one common ancestor that first evolved these traits...just like all hominids share one common ancestor?
We've abandoned that concept, since the development of genome sequencing. Ancestry is now determined by genetic differences, as natural selection ultimately acts upon DNA. Genes control anatomy in non-obvious ways.