Cryptic species

Diversification in Ancient Tadpole Shrimps Challenges the Term 'Living Fossil'

http://www.sciencedaily.com/releases/2013/04/130402091641.htm

I found this article rather interesting because it presents evidence against the controversial term "living fossil"...

Here's a snipet: 
"The term 'living fossil' has a controversial history. For decades, scientists have argued about its usefulness as it appears to suggest that some organisms have stopped evolving. New research has now investigated the origin of tadpole shrimps, a group commonly regarded as 'living fossils' which includes the familiar Triops. The research reveals that living species of tadpole shrimp are much younger than the fossils they so much resemble, calling into question the term 'living fossil'...For example, 250-million-year-old fossils have been assigned to the living European speciesTriops cancriformis whereas the team's results indicate that the living T. cancriformis evolved less than 25 million years ago."