Quote from shortie:
it has not changed dramatically, but it surely changed in some ways you may not be able to see in the fossils.
let's ignore the small changes for now. the species got "frozen" over millions of years, does it disprove the evolutionary process? no. give it 10M more years, pollute the ocean a bit, etc. it will be forced to evolve or will die off.
some species can be stable for 100K years, a few for 10M, etc. why not? if a species found a stable environment for which it fits very well, it won't change much for a long period of time. there is no pressure.
the reason we see so many species come and go (mostly via dying off with few evolving into something else) is because the environment changes (ice age, etc): adapt or die.