Actually, that was Lingchih's claim. I'm not the one that started this whole mess
but I have heard-and generally accept-that certain species of plants aren't all that removed from animals. I could also accept that fungi are even closer to animals than other types of plants, because they have some animal-like qualities-for instance not requiring sunlight as their direct and primary source of fuel. That would therefore suggest-should it all be biologically correct-that yes, some fungi *are* closer to humans than other plants, and allow the possibility of some animals-having split off before plants, or what have you, to be further removed from humans than other animals.
The horseshoe crab, I would think, would make a likely candidate. Someone ought to do something with horseshoe crabs for Dominions-they really are quite strange creatures. Trichordates might be fun too.