Lazarus taxon

The takahe is an example of a Lazarus taxon.

In paleontology, a Lazarus taxon (plural taxa) is a taxon that disappears from one or more periods of the fossil record, only to appear again later. The term refers to an account in the Gospel of John, in which Jesus miraculously raised Lazarus from the dead. Lazarus taxa are observational artifacts that appear to occur either because of (local) extinction, later resupplied, or as a sampling artifact. If the extinction is conclusively found to be total (global or worldwide) and the supplanting species is not a lookalike (an Elvis species), the observational artifact is overcome. The fossil record is inherently imperfect (only a very small fraction of organisms become fossilized) and contains gaps not necessarily caused by extinction, particularly when the number of individuals in a taxon becomes very low. If these gaps are filled by new fossil discoveries, a taxon will no longer be classified as a Lazarus taxon.

Terminology

The terms "Lazarus effect" or "Lazarus species" have also found some acceptance in neontology — the study of extant organisms, as contrasted with paleontology — as an organism that is rediscovered alive after having been widely considered extinct for years (a recurring IUCN Red List species for example). Examples include the Wollemi pine, the Jerdon's courser, the ivory-billed woodpecker (disputed), the Mahogany Glider and the takahē, a flightless bird endemic to New Zealand.^[1] However, in these cases being "extinct" strongly relates to the sampling intensity and the whims^{[neutrality disputed]} of the IUCN, and that such a period of apparent extinction is too short for species to be designated as "Lazarus taxa" (in its paleontological meaning).

Lazarus taxa that reappear in nature after being known only as old enough fossils can be seen as an informal subcategory of the journalist's "living fossils", because a taxon cannot become globally extinct and reappear. If the original taxon went globally extinct, the new taxon must be an Elvis taxon. On the other hand, all species "correctly considered living fossils" (with all conditions fulfilled, living and found through a considerable part of the geologic timescale) cannot be Lazarus taxa.

Reappearing species

Reappearing fossil taxa

Coelacanth Latimeria chalumnae.

• Coelacanth (Latimeria), a member of a clade (Coelacanthimorpha) thought to have gone extinct 80 million years ago; found in 1938.
• Monoplacophora, a class of Molluscs believed to have gone extinct in the middle Devonian Period (c. 380 million years ago) until living members were discovered in deep water off Costa Rica in 1952.
• Laotian Rock Rat (Laonastes aenigmamus), a member of a clade (Diatomyidae) thought to have gone extinct 11 million years ago; found in 1996.
• Monito del Monte (Dromiciops), a member of a clade (Microbiotheria) thought to have gone extinct 11 million years ago.
• Lazarussuchus, an Oligocene member of a clade of freshwater reptiles (Choristodera) thought to have gone extinct at the end of the Mesozoic. As Lazarussuchus is thought to be outside the clade including other choristoderans, it may indicate a ghost lineage going back to the Late Triassic, a span of over 170 million years.
• Gracilidris, a genus of dolichoderine ants thought to have gone extinct 15-20 million years ago was found in Paraguay, Brazil, and Argentina and described in 2006.
• Dawn Redwood or Metasequoia, a genus of conifer, was first described as a fossil from the Mesozoic Era by Shigeru Miki in 1941, but in 1944 a small stand was discovered in China in Modaoxi by Zhan Wang.
• Wollemi Pine (Wollemia), a species previously known only from fossils from 2 to 90 million years old representing a new genus of Araucariaceae, was discovered in 1994.
• Nightcap Oak (Eidothea hardeniana) and E. zoexylocarya, representing a genus previously known only from fossils 15 to 20 million years old, were recognized in 2000 and 1995, respectively.
• Chacoan Peccary (Catagonus wagneri), known to scientists only from fossils before its discovery in 1975.^[2]
• Mountain Pygmy Possum (Burramys parvus), Australia's only truly hibernating marsupial, known originally from the fossil record and then discovered in 1966 this species is again facing extinction due to global warming, introduced predator species and habitat loss.^[3]

Reappearing IUCN red list species

Plants

• Mount Diablo buckwheat (Eriogonom truncatum) — Thought extinct around 1935 but found again in 2005.
• Furbish's lousewort (Pedicularis furbishiae) - Canadian species identified as an extinct species in 1880, rediscovered in the 1970s.
• Camellia piquetiana, long known only from 19th century herbarium specimens labeled as Thea piquetiana until it was rediscovered in Vietnam in 2003.
• Blunt Chaff Flower (Achyranthes mutica)
• Climbing Alsinidendron (Alsinidendron viscosum)
• Jellyfish tree (Medusagyne oppositifolia)
• She cabbage tree (Lachanodes arborea)
• Virginia Round-leaf Birch (Betula uber)
• Sicilian Fir (Abies nebrodensis)
• Afrothismia pachyantha
• Antirhea tomentosa
• Asplundia clementinae
• Badula platyphylla
• Bulbophyllum filiforme
• Cyanea dunbariae
• Cyanea procera
• Eugenia bojeri
• Mammillaria schwarzii
• Medemia argun
• Pittosporum tanianum
• Takhtajania perrieri
• Turbinicarpus gielsdorfianus
• Bulbostylis neglecta

Invertebrates

• Madeiran land snail (Discus guerinianus) — Thought extinct in 1996 but found again in 1999.
• Lord Howe Island stick insect (Dryococelus australis); thought to be extinct by 1930 — rediscovered in 2001.
• Giant Palouse earthworm (Driloleirus americanus); thought extinct in 1980s, but found again in 2006.
• Xylotoles costatus, New Zealand longhorn beetle, considered extinct from 1986 to 1996, found again on Chatham Islands^[4]
• Nothomyrmecia macrops, Australian ant discovered in 1931, not seen again until 1977.
• Canterbury knobbed weevil (Karocolens tuberculatus), last seen in 1922 until it was rediscovered near Lake Tekapo in December 2004.

Amphibians

• Armoured Frog (Litoria lorica)
• Painted frog (Atelopus ebenoides marinkellei) Believed extinct 1995, rediscovered in 2006.
• Atelopus laetissimus
• Atelopus nahumae
• Bufo cristatus
• Bufo sumatranus
• Isthmohyla rivularis
• Ixalotriton niger
• Philautus chalazodes
• Taudactylus rheophilus
• Thorius minutissimus
• Telmatobufo venustus was not seen from 1899 until 1999.

Reptiles

• La Palma Giant Lizard (Gallotia auaritae) Thought to have been extinct since 1500, but rediscovered in 2007.
• La Gomera Giant Lizard (Gallotia bravoana)
• Phoboscincus bocourti, a 50-cm-long lizard, was previously known from a single specimen captured around 1870 and was long presumed extinct. In 2003, on a tiny islet, it was rediscovered.
• New Caledonian Crested Gecko (Rhacodactylus ciliatus)
• Arakan Forest Turtle (Heosemys depressa) was last seen in 1908 but found again in 1994.
• Gray's monitor (Varanus olivaceus), was described in 1845, and not seen again by scientists for 130 years

Mammals

• Fernandina rice rat (Nesoryzomys fernandinae) — Thought extinct in 1996 (last seen 1980) but found again in late 1990s.
• Bavarian pine vole (Microtus bavaricus) - believed extinct in the 1960s, but rediscovered in 2000.
• Woolly flying squirrel (Eupetaurus cinereus) - known only from pelts collected in Pakistan in the late nineteenth century, until live specimens were collected in the 1990s.
• Yellow-tailed woolly monkey (Lagothrix flavicauda)
• Gilbert's Potoroo (Potorous gilbertii), extremely rare Australian mammal presumed extinct from 1800s until 1994.
• Central Rock Rat (Zyzomys pedunculatus)
• New Holland Mouse (Pseudomys novaehollandiae) was first described by George Waterhouse in 1843, it vanished from view for over a century before its rediscovery in Ku-ring-gai Chase National Park north of Sydney, in 1967.
• Brazilian Arboreal Mouse (Rhagomys rufescens)
• Philippine bare-backed fruit bat (Dobsonia chapmani)
• Flat-Headed Myotis (Myotis planiceps)
• Tammar Wallaby (Macropus eugenii eugenii), this Australian subspecies was presumed extinct from 1925 until genetically matched with imported species in New Zealand in 1998.
• Cuban Solenodon (Atopogale cubanus), thought to have been extinct until a live specimen was found in 2003.
• Leadbeater's Possum (Gymnobelideus leadbeateri), thought to be extinct until 1965

Birds

• Ivory-billed woodpecker (Campephilus principalis) — Thought extinct circa 1987 before unconfirmed sightings in 1999 and 2004.
• Jerdon's Courser (Rhinoptilus bitorquatus) — A wader from India, assumed extinct until 1986.
• Madagascar serpent-eagle (Eutriorchis astur) - rediscovered in 1993, sixty years since the previous sighting.
• Grand Comoro scops-owl (Otus pauliani).
• Takahe (Porphyrio hochstetteri) — Assumed extinct in 1898 but found again in 1948.
• New Zealand storm-petrel — Believed extinct from 1850 but sighted again in 2003.
• Bermuda Petrel or "Cahow" (Pterodroma cahow) — Thought extinct since 1620 until three dozen were found in 1951 on a remote, uninhabited rock outcropping in Bermuda.
• Forest Owlet (Heteroglaux blewitti) — Assumed extinct in the 19th century, but rediscovered in central India in 1997.
• Night Parrot (Pezoporus occidentalis), extremely rare Australian bird presumed extinct from 1880s until 1990.
• Edwards's Pheasant (Lophura edwardii), a Vietnamese pheasant presumed extinct from 1928 was rediscovered in 1998.
• Bruijn's Brush-turkey (Aepypodius bruijnii)
• Madagascar Pochard (Aythya innotata), thought extinct since 1991 until a small group were spotted in 2006.
• Kaempfer's Woodpecker (Celeus obrieni), a Brazilian woodpecker feared extinct after no specimen had been found since its discovery in 1926. Rediscovered in 2006.
• Cone-billed Tanager (Conothraupis mesoleuca) a Tanager species that was undetected from 1938 to 2003, but was then rediscovered in gallery forest in Emas National Park.
• White-winged Guan (Penelope albipennis)
• Large-billed Reed-warbler (Acrocephalus orinus), a warbler rediscovered in Thailand in 2006, previous known only from a specimen collected in India in 1867.
• Utila Chachalaca (Ortalis vetula deschauenseei), subspecies of the Plain Chachalaca from Honduras, not recorded between 1963 and 2000 and confirmed with a photograph in 2005
• São Tomé Fiscal (Lanius newtoni)
• Stresemann's Bristlefront (Merulaxis stresemanni)
• Banggai Crow (Corvus unicolor) not recorded since 1884/1885, confirmed with a photograph in 2008
• White-collared Kite (Leptodon forbesi)
• São Tomé Grosbeak (Neospiza concolor)
• Long-legged Warbler (Trichocichla rufa)
• Bahia Tapaculo (Eleoscytalopus psychopompus)
• Cebu Flowerpecker (Dicaeum quadricolor)
• Berlepsch's Parotia (Parotia berlepschi)
• Golden-fronted Bowerbird (Amblyornis flavifrons)
• Noisy Scrub-bird (Atrichornis clamosus)
• Beck's Petrel (Pseudobulweria beckii), not seen between 1929 and 2007
• Fiji Petrel (Pseudobulweria macgillivrayi), first rediscovered on land in 1983, at the sea in 2009
• Silvery Pigeon (Columba argentina), confirmed with a photograph in 2008

See also

• Elvis taxon
• Signor-Lipps effect
• Living fossil
• List of extinct animals
• List of fossil sites (with link directory)
• Zombie taxon

References