Any living species of organism that seems to be the same as a species previously only know from the fossil record,and which has no close living relatives, is known as a living fossil. Such species exhibit very low diversity, and have survived all known major extinction events. In other words, the species has somehow lived for millions of years without evolving in any significant manner.
FAMOUS EXAMPLES OF LIVING FOSSILS
Some species considered living fossils were known from fossils before living representatives were discovered. Two of the most famous examples of this are the Coelocanth and the Ginkgo.
The coelocanth is a fish that was thought to have been extinct since the Late Cretaceous period. However, live specimens were "rediscovered" by fishermen in 1938 off the coast of South Africa! The coelacanth is believed to have first evolved some 400 million years ago. Since 1938, living members of the species Latimeria chalumnae have been found in the Comoros, Kenya, Tanzania, Mozambique, Madagascar, and in iSimangaliso Wetland Park, and Kwazulu-Natal in South Africa.
A second living coelocanth species, Latimeria menadoensis was first found in Manado Sulawesi, Indonesia in 1997 by a marine biologist on a honeymoon! The specimen was discovered and photographed at a local market before being bought by a shopper. The first live specimen of L. menadoensis was caught in July 1998 in Indonesia.
Another well known example of a living fossil is that of the Ginkgo biloba, also known as the Maidenhair Tree. The G. biloba is classified in its own division, the Ginkgophyta, comprising the single class Ginkgoopsida, order Ginkgoales, family Ginkgoaceae, genus Ginkgo and is the only living species within this group.
Ginkgo fossils recognizably related to modern Ginkgo date from the Permian, some 270 million years ago. At the end of the Pliocene, Ginkgo fossils disappeared from the fossil record everywhere except in a small area of central China where the modern species survived.
MORE EXAMPLES OF LIVING FOSSILS
----Monkey Puzzle tree - Araucaria araucana
----Horsetails – Equisetum (Equisetaceae)
----Dawn Redwood - Metasequoia
----Sciadopitys tree (Sciadopityaceae)
----Liquidamber tree (Altingiaceae)
----Whisk ferns – Psilotum (Psilotaceae)
----Aardvark (Orycteropus afer)
----Amami rabbit (Pentalagus furnessi)
----Cypriot mouse (Mus cypriacus)
----Elephant shrew (Macroscelidea)
----Koala (Phascolarctos cinereus)
----Laotian Rock Rat (Laonastes aenigmamus)
----Panthers (Lions, Leopards, and other relatives)
----Monotremes (the platypus and echidna)
----Okapi (Okapia johnstoni)
----Red Panda (Ailurus fulgens)
----Giant Panda (Ailuropoda melanoleuca)
----Sumatran Rhinoceros (Dicerorhinus sumatrensis)
----New Zealand "wrens" - Acanthisittidae
----Broad-billed Sapayoa (Sapayoa aenigma)
----Magpie Goose (Anseranas semipalmata)
----Andean Condor (Vultur gryphus) and California Condor (Gymnogyps californianus) - two living members of the New World Vultures.
----Osprey (Pandion haliaetus) and Northern Crested Caracara (Caracara plancus) - two living members of the Raptor family.
----Alligator Snapping Turtle (Macrochelys temminckii)
----Crocodiles, Gavials and Alligators - Crocodilia
----Komodo Dragon (Varanus komodoensis)
----Pig-nosed turtle (Carettochelys insculpta)
----Snapping Turtle (Chelydra serpentina)
----Tuatara (Sphenodon punctatus and Sphenodon guntheri)
----Giant salamanders (Cryptobranchus, and Andrias)
----Purple frog (Nasikabatrachus sahyadrensis)
----Northern Brook Lamprey (Ichthyomyzon fossor)
----Bowfin (Amia calva)
----Queensland lungfish (Neoceratodus fosteri)
----Sturgeons and Paddlefish (Acipenseriformes)
----Hagfish (Myxinidae) Family
----Blind shark (Brachaelurus waddi)
----Bullhead shark (Heterodontus sp.)
----Elephant shark (Callorhinchus milii)
----Frilled shark (Chlamydoselachus sp.)
----Goblin Shark (Mitsukurina owstoni)
----Gulper Shark (Centrophorus sp.)
Fish Caught in Time: The Search for the Coelacanth
On Methuselah's Trail: Living Fossils and the Great Extinctions