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Living fossil

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Title: Living fossil  
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Subject: Arboretum at the University of California, Santa Cruz, Lazarus taxon, Extinction, Goblin shark, Frilled shark
Collection: Evolutionary Biology, Extinction, Fossils, Living Fossils
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Living fossil

The coelacanths were thought to have gone extinct , until a living specimen belonging to the order was discovered in 1938.

A living fossil is a living fossils, typically with no close living relatives. Normally the similarity is only by an imagined physical resemblance, between two different species, one extinct, the other extant. It is an informal non-scientific term, mostly used in the lay media.

These species have survived major extinction events, and generally retain low taxonomic diversities. A species that successfully radiates (forming many new species after a possible genetic bottleneck) has become too successful to be considered a living fossil.


  • Overview 1
  • History 2
    • Other definitions 2.1
      • long-enduring 2.1.1
      • resembles ancient species 2.1.2
      • retains many ancient traits 2.1.3
      • relict population 2.1.4
      • low diversity 2.1.5
  • Examples 3
    • Bacteria 3.1
    • Protists 3.2
    • Plants 3.3
    • Fungi 3.4
    • Animals 3.5
  • See also 4
  • References 5
  • External links 6


Fossil and living ginkgos
170 million-year-old fossil Ginkgo leaves
Living Ginkgo biloba plant

A subtle difference is sometimes made between a "living fossil" and a "Lazarus taxon". A Lazarus taxon is a taxon (either one species or a group of species) that suddenly reappears, either in the fossil record or in nature (i.e., as if the fossil had "come to life again"), while a living fossil is a species that (seemingly) has not changed during its very long lifetime (i.e., as if the fossil species has always lived). The average species turnover time (the time a species lasts before it is replaced) varies widely among the phyla, but averages about 2–3 million years. So, a living species that was thought to be extinct (e.g., the coelacanth, Latimeria chalumnae) could be called a Lazarus taxon instead of a living fossil. Coelacanths disappeared from the fossil record some 80 million years ago (upper Cretaceous). Of course, species do not just appear out of nothing, so all living Lazarus species (excluding disappearing and reappearing red list species) are nonetheless considered living fossils, if it can be shown they are not Elvis taxa.

Lastly, the term "living fossil" misleadingly appears to suggest that the organism has somehow "stopped evolving". Tadpole shrimp ([1] It should be noted that several recent studies pointed out that the morphological conservatism of coelacanths is a myth that is not supported by actual paleontological data.[2][3] In addition, it was shown recently that studies concluding that a slow rate of molecular evolution is linked to morphological conservatism in coelacanths are biased by the a priori hypothesis that these species are ‘living fossils’[4]

Some living fossils are taxa that were known from fossils before living representatives were discovered. The most famous examples of this are the coelacanthiform fishes Latimeria chalumnae and Latimeria menadoensis and the [5]

Note that just because a living fossil is a surviving representative of an archaic lineage does not necessarily require that it retains all of the "primitive" features (plesiomorphies) of the lineage it is descended from; that is, they may possess one to many derived features (autapomorphies), that have evolved since the time of their lineage's divergence. All that is required is that they can be unambiguously assigned to an otherwise extinct lineage (rarely are they identical to the fossil forms). See for example the uniquely and highly autapomorphic oxpeckers, which are not "true" living fossils (as no fossils are known yet) but nonetheless appear to be the only survivors of an ancient lineage related to starlings and mockingbirds.[6]


The term was coined by Charles Darwin in his On the Origin of Species, when discussing Ornithorhynchus (the platypus) and Lepidosiren (the South American lungfish):

... All fresh-water basins, taken together, make a small area compared with that of the sea or of the land; and, consequently, the competition between fresh-water productions will have been less severe than elsewhere; new forms will have been more slowly formed, and old forms more slowly exterminated. And it is in fresh water that we find seven genera of Ganoid fishes, remnants of a once preponderant order: and in fresh water we find some of the most anomalous forms now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders now widely separated in the natural scale. These anomalous forms may almost be called living fossils; they have endured to the present day, from having inhabited a confined area, and from having thus been exposed to less severe competition.[7]

Other definitions

An organism's living fossil status can be rejected if the (smallest) clade the species belongs to is species rich, as this would imply (recent) speciation. That not being the case, there are several definitions for “living fossils”:


A living taxon that lived through a large portion of geologic time.

Elephant shrews resemble the extinct Leptictidium of Eocene Europe.

To prove this, all living specimens must belong to the same fossil species. This rules out Limulus, Peripatus, Latimeria, Sphenodon, Didelphis, the platypus, and many others. To allow some flexibility, the genus could be used.

Paleontological taxonomy relies on hard-part morphology (the paleontological species concept), so there is a bias towards longer species turnover times, and relationships can only be inferred partially. Modern molecular biology has shown that genetic rates of change are relatively uniform and not well related to morphological change rates. So from a more molecular basis of interbreeding capabilities there are essentially no such thing as species that lived through a long geological time. However, with the proviso that we are using the special case of a paleontological species name, the definition does hold together in context.

Queensland lungfish (Neoceratodus fosteri) is an example of an organism that meets this criteria, fossils identical to modern Queensland lungfish have been dated at over 100 million years making this species one of the oldest if not actually the oldest extant vertebrate species.

resembles ancient species

A living taxon morphologically and/or physiologically resembling a fossil species through a large portion of geologic time (morphological stasis).[8]

The living specimens need not belong to the same fossil species (or even genus). There must at least be some physiological resemblance.

The coelacanth for example, is a marine fish. The Mesozoic coelacanth species lived in salt and fresh water. Osmoregulation in Latimeria is handled by urea retention. Urea retention is considered to indicate fresh water ancestry. This means that the coelacanth lineage evolved from freshwater to saltwater.

The resemblance between Peripatus and Aysheaia (an early Cambrian animal from the Burgess Shale) would be striking (both are classified in the Tardipolypoda, Tardigrada, and Onychophora), were it not that Aysheaia was a marine animal, while Peripatus lives in tropical leaf mould.

retains many ancient traits

A living taxon with many characteristics believed to be primitive.

This is a more neutral definition. However, it does not make it clear whether the taxon is truly old, or it simply has many plesiomorphies. Note that, as mentioned above, the converse may hold for true living fossil taxa; that is, they may possess a great many derived features (autapomorphies), and not be particularly "primitive" in appearance.

More primitive trapdoor spiders, such as this female Liphistius sp., have segmented plates on the dorsal surface of the abdomen and cephalothorax, a character shared with scorpions, making it probable that after the spiders diverged from the scorpions, the earliest unique ancestor of trapdoor species was the first to split off from the lineage that contains all other extant spiders.

relict population

Any one of the above three definitions, but also with a relict distribution in refuges.

Some paleontologists believe that living fossils with large distributions (such as Triops cancriformis) are not real living fossils. In the case of Triops cancriformis (living from the Triassic until now), the Triassic specimens lost most of their appendages (mostly only carapaces remain), and they have not been thoroughly examined since 1938.

low diversity

Any of the first three definitions, but the clade also has a low taxonomic diversity (low diversity lineages).

Oxpeckers are morphologically somewhat similar to starlings due to shared plesiomorphies, but are uniquely adapted to feed on parasites and blood of large land mammals, which has always obscured their relationships. This lineage forms part of a radiation that includes Sturnidae and Mimidae, but appears to be the most ancient of these groups. Biogeography strongly suggests that oxpeckers originated in eastern Asia and only later arrived in Africa, where they now have a relict distribution.[6] The two living species thus seem to represent an entirely extinct and (as Passerida go) rather ancient lineage, as certainly as this can be said in the absence of actual fossils. The latter is probably due to the fact that the oxpecker lineage never occurred in areas where conditions were good for fossilization of small bird bones, but of course, fossils of ancestral oxpeckers may one day turn up enabling this theory to be tested.


Ginkgos have not only existed for a long time, but also have a long life span, with some having an age of over 2,500 years. Six specimens have even been known to survive the atomic bombing of Hiroshima, 1 to 2 kilometers from ground zero; they still live there today.

Some of these are informally known as "living fossils".





    • Amborella – a plant from New Caledonia, possibly closest to base of the flowering plants
    • Sycamore tree - leaves of fossil sycamores have an incredibly similar phenotype to those living today
    • Trapa - water caltrops, seeds, and leaves of numerous extinct species are known all the way back to the Cretaceous.
    • Nelumbo - several species of lotus flower are known exclusively from fossils dating back to the Cretaceous.



See also


  1. ^ Science Daily"Diversification in Ancient Tadpole Shrimps Challenges the Term 'Living Fossil'" accessed 2 April 2013; "The Falsity of 'Living Fossils'", The Scientist accessed 2 April 2013.
  2. ^ Friedman M, Coates MI, Anderson P; Coates; Anderson (2007). "First discovery of a primitive coelacanth fin fills a major gap in the evolution of lobed fins and limbs". Evolution & Development 9 (4): 329–37.  
  3. ^ Friedman M, Coates MI; Coates (2006). "A newly recognized fossil coelacanth highlights the early morphological diversification of the clade". Proc. R. Soc. B. 273 (1583): 245–250.  
  4. ^ Casane D, Laurenti P; Laurenti (Feb 2013). "Why Coelacanths are not "Living fossils" : a Review of Molecular and Morphological Data". BioEssays 35 (4): 332–8.  
  5. ^ a b Mertens, K.N.; Takano, Y.; Head, M.J.; Matsuoka, K. (2014). "Living fossils in the Indo-Pacific warm pool: A refuge for thermophilic dinoflagellates during glaciations". Geology 42 (6): 531–534.  
  6. ^ a b Dario Zuccon, Anne Cibois, Eric Pasquet & Per G. P. Ericson; Cibois; Pasquet; Ericson (2006). "Nuclear and mitochondrial sequence data reveal the major lineages of starlings, mynas and related taxa" (PDF).  
  7. ^ On the Origin of Species, 1859, p. 107.
  8. ^ "Scientists find lamprey a 'living fossil'"The University of Chicago Medical Center: . 2006-10-26. Retrieved 2012-05-16. 
  9. ^ Hagino, K.; Young, J. R.; Bown, P. R.; Godrijan, J.; Kulhanek, D.; Kogane, K.; Horiguchi, T. (2015). "Re-discovery of a "living fossil" coccolithophore from the coastal waters of Japan and Croatia". Marine Micropaleontology 116 (1): 28–37.  
  10. ^ Chambers, T.C.; Drinnan, A.N.; McLoughlin, S. (1998). "Some morphological features of Wollemi Pine (Wollemia nobilis: Araucariaceae) and their comparison to Cretaceous plant fossils". International Journal of Plant Science 159: 160–171.  
  11. ^ McLoughlin S., Vajda V.; Vajda (2005). "Ancient wollemi pines resurgent". American Scientist 93 (6): 540–547.  
  12. ^ "Why Is the Okapi Called a Living Fossil". The Milwaukee Journal. Jun 24, 1954. 
  13. ^ Fordyce, R. E.; Marx, F. G. (2013). "The pygmy right whale Caperea marginata: the last of the cetotheres". Proceedings of the Royal Society B: Biological Sciences 280 (1753): 1–6.  
  14. ^ Extinct' whale found: Odd-looking pygmy whale traced back 2 million years"'". April 23, 2012. Retrieved December 19, 2012. 
  15. ^ Switek, Brian. "Repost: The Pelican's Beak - Success and Evolutionary Stasis | Wired Science".  
  16. ^ Morelle, Rebecca. "'"Rediscovered Hula painted frog 'is a living fossil. BBC News. Retrieved 4 June 2013. 

External links

  • Scientists find lamprey a 'living fossil'
  • as living fossilsTriopsMyTriops introduces
  • information about living fossils
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