Given the problems with lumping some things into clades then excluding others, how would you suggest defining "fish" and "not fish"?
Why stop at fish? Why not cephalochordates?
Common ancestors and all.
Prollu coz nobody takes a hook and line and says
they will go cephalochordating.
Bony fish, Osteichthys or however it's spelled,
those are fish.
Chondr- whatever are sharks and rays. Not fish.
Different classes, a pretty high level of distinction.
How about worms? There's what, three phyla
of very different animals but theys little, long,
and skinny so theys all worms.
For those who never studied biology, figure
spiders, grasshoppers, and pillnugs are all bugs while
all long wriggly things are worms, and,
swimmy things are all fish, go for it.
I like some useful meaning in words.
"Bats are fish" is just stupid.
As for the inveterate lumpers and divers other base
and ignoble citizens, why not replace all nouns with "thing",
make namenclature even simpler.