A living tree which seems to be, or resemble, a member of a species of tree which was last seen in the fossil record about 150 million years ago exists in a small population in Australia.
Some creationists see this as evidence for creationism and a fact that casts serious doubt on the theory of evolution (
http://www.answersingenesis.org/creation/v17/i2/tree.asp).
Let's assume that the trees found (approximately 38 examples) are in fact living representatives of the exact species previously thought to be extinct for 150 million years. Creationists ask us to explain 1 ) why none have been found in intervening strata of fossils and 2) why these trees have not "evolved" in 150 million years?
Since their hypothesis is that modern formed human remains should be found in most strata I would ask why their are no confirmed human remains found existing 150 Million years ago (or much less as a young earth proponents would argue) with these trees and other animals. Their answer might rely on "the flood" or if they are more logical they might say the human population was small then, since we started from just 2 humans, and therefore we have not searched enough of the fossil record to find them. The same argument holds, more convincingly, for the Wollemi Pine. If only 39 exist today it's coverage over the globe, and accordingly it's representation in the fossil record, would have diminished over time. The evolutionist would answer that if these are in fact the same trees thought to be extinct 150 million years then we should find fossil records of them in intervening strata near the only known living specimens and then we could work our way back through time to tell when they became so localized. In brief answer to 1) We haven't found them for 150 million years because the population dwindled and we haven't searched absolutely every layer of earth, perhaps if all the creationists started digging we could get a portion of the earth catalogued now.
In answer to question 2) it is a misrepresentation of the theory of evolution to say that "everything evolves all the time." The existence of any organism in it's apparently "unevolved" form for a period of time is merely a testament to the versatility of the last adapted form.
The theory of evolution admits the existence of the Wollemi pine as a living thing even while accepting the accuracy of the dating methods which show it absent of the known fossil record for 150 million years.