Wollemi Pine -- a living fossil
When scientists announced the discovery of the Wollemi Pine in Australia, in 1994, it caused a sensation. Some reported that it was like finding a living dinosaur, because the tree was only known from fossils in 'Jurassic' rocks. That would make it extinct for 150 million years, by evolutionary reckoning.
Finds like this are actually quite common. When something that scientists thought became extinct millions of years ago is found alive, it's called a 'living fossil'. But 'living fossils' pose a problem for evolution—since the organism hasn't changed, it brings into question the supposed millions of years age as well as the very idea of evolution.
When a tree was planted in London, recently, Sir David Attenborough said: 'It is romantic, I think, that something has survived 200 million years unchanged'. Perhaps he considers it romantic, but this observation makes the millions of years of evolution very hard to believe.