Which species would that be?
PS YEC Creationists believe in change over time. They just don't believe in Darwin's “Tree of Life” (creationists believe in an “Orchard of Life”) and they don't believe species can change beyond the confines of the original separately created kinds.
That’s pretty odd as surviving animals altered quickly and radically to adapt to changing conditions while the weaker “branches” didn’t make it. In our records the sloths (lots of skeletons) went from giants to the little creatures we know today, the whales went form land dwellers to sea (still apparent in their current skeletal structure) while most of the rodent class clings to the aggressive arrogance they deserved when they were five times the size they are now.
Since the 1500’s we humans have gained 10 inches of average growth in height.
So YEC’s don’t believe in evolution - but they do believe in superduper 3000x evolution?
That really doesn’t make a lick of sense.