"pushes back the history of animal evolution tens of millions of years"
Looks like the science of evolution was on shaky ground, if one fossil can make such a big change in the theory...
If evolution was unaffected by the discovery, you'd call it dogma. If the theory is modified to accomodate new data, it's "on shaky ground." Damned if you do....
By the way, how many fossils were found?