Living fossil

Living fossil is a term used for any living species which closely resembles a species otherwise only known from fossils, i.e., as if the fossil had "come to life".

This can be a species known from fossils before living representatives were discovered (the most famous example of this is the coelacanth fish, Latimeria chalumnae), or a single living species with no close relatives, but which is the sole survivor of a once large and widespread group in the fossil record (the best-known example of this is the ginkgo tree, Ginkgo biloba).

Note the similarity between the 170 million year old fossil Ginkgo leaves on the left, and the living plant on the right.

Other living fossils are the horsetails, nut clams (Ennucula superba), Lingula anatina (an inarticulate brachiopod), the tuatara lizard, the snout-nosed nasikabatrachus sahyadrensis frog, and the horseshoe crab (Limulus polyphemus).