Dead wood, so to speak.
Some species survived for hundreds of thousands of years before conditions or competition (i.e., us) drove them to extinction.
This chart shows over two dozen pre-human or early-human species or sub-species before our own homo sapiens sapiens.
Here's another visualization of the data:
Let’s stretch the metaphor,
Like I said, branches lying all around, but not on the tree. Some so-called botanists tell us all of these branches fell off this particular tree, and (coincidentally) there’s only one branch left.
But they keep discovering that the limbs are maple, cedar, and whatnot, instead of the oak tree they supposedly fell off of.
And not only that, but there’s that one branch that is practically the whole tree now, with no other branches attached to the tree at all.
That one branch assuredly couldn’t have sucked all the sap from those other branches that happened to coexist, could they? And even if they could, can we pinpoint the events that killed off those 20 something branches before the branches started competing amongst each other?