Some species have apparently changed very little in hundreds of millions of years and are sometimes called "living fossils". One of them is the ginkgo tree, whose reproductive strategy is older than both conifers and flowering plants. Ginkgo trees very similar to those around today cast their shadows on the first and the last of the dinosaurs, which I find quite mind-boggling.
I've written a short essay review on the book
Ginkgo: The tree that time forgot, by Peter Crane,
which is out in the August issue of Chemistry & Industry, page 49.