Tuatara

This article is about the animal. For other uses, see Tuatara (disambiguation).

Tuatara
Temporal range: Early Miocene – present, 19–0 Ma [1]
Northern tuatara (Sphenodon punctatus punctatus)

Relict (NZ TCS)[4]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Rhynchocephalia
Family: Sphenodontidae
Genus: Sphenodon
Gray, 1831 (conserved name)
Species:
S. punctatus
Binomial name
Sphenodon punctatus
(Gray, 1842) (conserved name)
Native range (New Zealand)
Current distribution of tuatara (in black):[5][6][7] Circles represent the North Island tuatara, and squares the Brothers Island tuatara. Symbols may represent up to seven islands.
Synonyms
  • Sphaenodon
    (Gray, 1831) (rejected name)
  • Hatteria
    (Gray, 1842) (rejected name)
  • Rhynchocephalus
    (Owen, 1845) (rejected name)

The tuatara (Sphenodon punctatus) is a species of reptile endemic to New Zealand. Despite its close resemblance to lizards, it is part of a distinct lineage, the order Rhynchocephalia.[8] The name tuatara is derived from the Māori language and means "peaks on the back".[9]

The single extant species of tuatara is the only surviving member of its order, which was highly diverse during the Mesozoic era.[10] Rhynchocephalians first appeared in the fossil record during the Triassic, around 240 million years ago,[11] and reached worldwide distribution and peak diversity during the Jurassic, when they represented the world's dominant group of small reptiles. Rhynchocephalians underwent a great decline during the Cretaceous with their youngest records outside New Zealand dating to the Paleocene. Their closest living relatives are squamates (lizards and snakes). Tuatara are of interest for studying the evolution of reptiles.

Tuatara are greenish brown and grey, and measure up to 80 cm (31 in) from head to tail-tip and weigh up to 1.3 kg (2.9 lb)[12] with a spiny crest along the back, especially pronounced in males. They have two rows of teeth in the upper jaw overlapping one row on the lower jaw, which is unique among living species. They are able to hear, although no external ear is present, and have unique features in their skeleton.

Tuatara are sometimes referred to as "living fossils",[8] which has generated significant scientific debate. This term is currently deprecated among paleontologists and evolutionary biologists. Although tuatara have preserved the morphological characteristics of their Mesozoic ancestors (240–230 million years ago), there is no evidence of a continuous fossil record to support this.[13][10] The species has between 5 and 6 billion base pairs of DNA sequence, nearly twice that of humans.[14]

The tuatara (Sphenodon punctatus) has been protected by law since 1895.[15][16] A second species, the Brothers Island tuatara S. guntheri, (Buller, 1877), was recognised in 1989,[12] but since 2009 it has been reclassified as a subspecies (S.p. guntheri).[17][18] Tuatara, like many of New Zealand's native animals, are threatened by habitat loss and introduced predators, such as the Polynesian rat (Rattus exulans). Tuatara were extinct on the mainland, with the remaining populations confined to 32 offshore islands[19] until the first North Island release into the heavily fenced and monitored Karori Wildlife Sanctuary (now named "Zealandia") in 2005.[20]

During routine maintenance work at Zealandia in late 2008, a tuatara nest was uncovered,[21] with a hatchling found the following autumn.[22] This is thought to be the first case of tuatara successfully breeding in the wild on New Zealand's North Island in over 200 years.[21]

  1. ^ "Sphenodon". Paleobiology Database. Archived from the original on 15 July 2020.
  2. ^ "Conservation status of plants and animals".
  3. ^ "IUCN Red List of Threatened Species".
  4. ^ "Sphenodon punctatus. NZTCS". nztcs.org.nz. Retrieved 3 April 2023.
  5. ^ Cite error: The named reference Daugherty_1990 was invoked but never defined (see the help page).
  6. ^ Gaze, P. (2001). Tuatara recovery plan 2001–2011 (PDF). Biodiversity Recovery Unit, Department of Conservation (Report). Threatened Species Recovery Plan. Vol. 47. Government of New Zealand. ISBN 978-0-478-22131-2. Archived from the original (PDF) on 5 November 2011. Retrieved 2 June 2007.
  7. ^ Beston, A. (25 October 2003). "Tuatara release" (PDF). New Zealand Herald. Archived from the original (PDF) on 4 October 2007. Retrieved 11 September 2007.
  8. ^ a b "Tuatara". New Zealand Ecology. Living Fossils. TerraNature Trust. 2004. Archived from the original on 3 May 2017. Retrieved 10 November 2006.
  9. ^ "The Tuatara". Kiwi Conservation Club. Fact Sheets. Royal Forest and Bird Protection Society of New Zealand. 2009. Archived from the original on 16 October 2015. Retrieved 13 September 2017.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  10. ^ a b Herrera-Flores, J.A., Stubbs, T.L., Benton, M.J. (2017). "Macroevolutionary patterns in Rhynchocephalia: is the tuatara (Sphenodon punctatus) a living fossil?". Palaeontology. 60 (3): 319–328. Bibcode:2017Palgy..60..319H. doi:10.1111/pala.12284.
  11. ^ Jones ME, Anderson CL, Hipsley CA, Müller J, Evans SE, Schoch RR (September 2013). "Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara)". BMC Evolutionary Biology. 13 (208): 208. Bibcode:2013BMCEE..13..208J. doi:10.1186/1471-2148-13-208. PMC 4016551. PMID 24063680.
  12. ^ a b "Reptiles:Tuatara". Animal Bytes. Zoological Society of San Diego. 2007. Archived from the original on 30 November 2012. Retrieved 1 June 2007.
  13. ^ Meloro, C., Jones, M.E. (November 2012). "Tooth and cranial disparity in the fossil relatives of Sphenodon (Rhynchocephalia) dispute the persistent 'living fossil' label". Journal of Evolutionary Biology. 25 (11): 2194–209. doi:10.1111/j.1420-9101.2012.02595.x. PMID 22905810. S2CID 32291169.
  14. ^ Elder, V. (26 November 2012). "Tuatara genome mapping". Otago Daily Times. Retrieved 10 June 2018.
  15. ^ Newman 1987
  16. ^ Cree, A., Butler, D. (1993). Tuatara Recovery Plan (PDF). Threatened Species Recovery Plan Series. Vol. 9. Threatened Species Unit, Department of Conservation, Government of New Zealand. ISBN 978-0-478-01462-4. Archived from the original (PDF) on 30 September 2012. Retrieved 2 June 2007.
  17. ^ Cree, A. (2014). Tuatara: Biology and conservation of a venerable survivor. Canterbury University Press. ISBN 978-1-927145-44-9.
  18. ^ Hay JM, Sarre SD, Lambert DM, Allendorf FW, Daugherty CH (2010). "Genetic diversity and taxonomy: a reassessment of species designation in tuatara (Sphenodon: Reptilia)". Conservation Genetics. 11 (3): 1063–1081. Bibcode:2010ConG...11.1063H. doi:10.1007/s10592-009-9952-7. hdl:10072/30480. S2CID 24965201.
  19. ^ "Tuatara". Conservation. Native Species. Threatened Species Unit, Department of Conservation, Government of New Zealand. Archived from the original on 31 January 2011. Retrieved 3 February 2013.
  20. ^ "Tuatara factsheet (Sphenodon punctatus)". Sanctuary Wildlife. Karori Sanctuary Wildlife Trust. Archived from the original on 21 October 2007. Retrieved 28 June 2009.
  21. ^ a b "New Zealand's 'living fossil' confirmed as nesting on the mainland for the first time in 200 years!" (Press release). Karori Sanctuary Trust. 31 October 2008. Archived from the original on 27 February 2013.
  22. ^ "Our first baby tuatara!" (Press release). Karori Sanctuary Trust. 18 March 2009. Archived from the original on 24 February 2023. Retrieved 25 July 2009.