Linnaeus named living and fossil brachiopods, so the modern ones have been known for a while.
I believe the gastropod genus Pleurotomaria was known from the fossil
record before living ones were found.
The modern ones are now moved to other genera, but the family Pleurotomariidae certainly was known as fossils before modern ones were found.
--
Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"