User blog comment:Kogath/Monster Hunter: World Discussion/@comment-25083735-20191105005322/@comment-25933225-20191110122202

The thing with their blood is probably something that has nothing to do with their relations or else. Maybe it's a matter of bioenergy or something like that : they all are species that ended with this in their blood (maybe some kind of magic) or something like that, but nothing to do with their classification. Which still mean the ecological tree of the elder dragon is still irrelevant because an ecological tree uses biological parameters and the relation between the elder dragons has nothing to do with biology but with their power.

But I don't think using the blood argument is that relevant : when we're talking about items from monsters we've got lots of nonsense (carving raw meat on jellyfishes). I think the item thing is just because it have a common thing (for jellyfish it'd be because we can carve some eatable stuff, for dragons that would be because there is magic in their blood or something like that), but that doesn't mean it's necessarilly identical from a specie to another.

And for the elder-dragon level monsters I don't have much to say, as we've already pointed out that even the other monster types have their nonsenses. It's just that the elder dragon class has the biggest amount of nonsense.

So my point is that there might be something uniting all of the elder dragon but that's not something related to their classification, as it's clear most of them are not related species. Magic seems to exist in this universe so maybe some random species ended up with magic within them, making their blood special.