Tuatara
30786
225159226
2008-07-12T05:24:23Z
Gadfium
54381
rv, already covered and referenced in "Behaviour" section
{{For|the experimental music band|Tuatara (band)}}
{{Taxobox
| name = Tuatara
| status = VU | status_system = IUCN2.3
| image = 128763115_a1b78f9cde_o.jpg
| image_width = 250px
| image_caption = Male tuatara
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| subphylum = [[Vertebrata]]
| superclassis = [[Tetrapoda]]
| classis = [[Reptile|Sauropsida]]
| subclassis = [[Diapsida]]
| infraclassis = [[Lepidosauromorpha]]
| superordo = [[Lepidosauria]]
| ordo = [[Sphenodontia]]
| familia = [[Sphenodontidae]]
| genus = '''''Sphenodon'''''
| genus_authority = [[John Edward Gray|Gray]], 1831
| range_map = World.distribution.rhynchocephalia.colour contrast.png
| range_map_caption = <font color="#D90000">dark red</font>: range (North Island, New Zealand)
| range_map_width = 250px
| subdivision_ranks = Species
| subdivision =
<!--PLEASE DO NOT WIKILINK THESE UNTIL YOU ARE CERTAIN THAT YOU CAN WRITE A FULL ARTICLE ON EACH SPECIES, CONTAINING ONLY NOTABLE AND VERIFIABLE INFORMATION-->
''Sphenodon punctatus'' <small>(Gray, 1842)</small><br/>
''Sphenodon guntheri'' <small>([[Walter Buller|Buller]], 1877)</small><br/>
<!--Lutz 1995 lists S. Gray as an extinct sp. with no authority or year given - pending confirmation from second source-->
''Sphenodon diversum'' <small>Colenso, 1885 (extinct)</small><br/>
| synonyms =
''Hatteria punctata'', <small>Gray 1842</small>
}}
The '''tuatara''' is an [[amniote]] of the family Sphenodontidae, [[endemism|endemic]] to [[New Zealand]]. The two species of tuatara are the only surviving members of the [[Sphenodontia]]ns which flourished around 200 million years ago,<ref name="animal">{{cite book | last=Burnie | first=David | coauthors=Don E. Wilson | title=Animal: The Definitive Visual Guide to the World's Wildlife | publisher=DK Publishing, Inc. | date=2001 | location=New York, New York | pages=375 | isbn=0-7894-7764-5 }}</ref> and are in the genus ''Sphenodon''. Tuatara resemble [[lizard]]s, but are equally related to lizards and [[snake]]s, both of which are classified as [[Squamata]], the closest living relatives of tuatara. For this reason, tuatara are of great interest in the study of the evolution of lizards and snakes, and for the reconstruction of the appearance and habits of the earliest [[diapsid]]s (the group that additionally includes [[bird]]s and [[crocodile]]s).<!--I don't intend to go into temporal fenestrae here-->
Tuatara are greenish brown, and measure up to 80 cm (32 in) from head to tail-tip<ref name = "san diego">{{cite web | title=Reptiles:Tuatara | work=Animal Bytes | publisher=Zoological Society of San Diego | date=2007 | url=http://www.sandiegozoo.org/animalbytes/t-tuatara.html | accessdate=2007-06-01 }}</ref> with a spiny crest along the back, especially pronounced in males. Their dentition, in which two rows of teeth in the upper jaw overlap one row on the lower jaw, is unique among living species. They are further unusual in having a pronounced [[parietal eye]], dubbed the "third eye", whose current function is a subject of ongoing research. They are able to hear although no external ear is present, and have a number of unique features in their skeleton, some of them apparently evolutionarily retained from fish. Although tuatara are sometimes called "[[living fossil]]s", recent taxonomic and molecular work has shown that they have changed significantly since the [[Mesozoic]] era.
The tuatara has been classified as an [[endangered species]] since 1895<ref>{{Harvnb|Newman|1987}}.</ref><ref>{{cite web| last=Cree | first=Allison | coauthors=David Butler | title=Tuatara Recovery Plan | work=Threatened Species Recovery Plan Series No.9 | publisher=Threatened Species Unit, Department of Conservation, Government of New Zealand | date=1993 | url=http://www.doc.govt.nz/upload/documents/science-and-technical/TSRP09.pdf | accessdate=2007-06-02 | isbn=0478014627 }}</ref> (the second species, ''S. guntheri'', was not recognised until 1989).<ref name="san diego"/>
Tuatara, like many of New Zealand's native animals, are threatened by habitat loss and the introduced [[Polynesian Rat]] ''(Rattus exulans)''. They were extinct on the mainland, with the remaining populations confined to 32 offshore islands,<ref name="DoC">{{cite web | title=Facts about tuatara | work =Conservation: Native Species| publisher =Threatened Species Unit, Department of Conservation, Government of New Zealand|url=http://www.doc.govt.nz/templates/page.aspx?id=33163 | accessdate=2007-02-10 }}</ref> until the first mainland release into the heavily fenced and monitored [[Karori Wildlife Sanctuary]] in 2005.<ref name="karori">{{cite web| title =Tuatara Factsheet (''Sphenodon punctatus'')| work =Sanctuary Wildlife| publisher =Karori Sanctuary Wildlife Trust| url =http://www.sanctuary.org.nz/restoration/forest/tuatara/tuatara-facts.html| accessdate = 2007-06-02 }}</ref>
The name "tuatara" derives from the [[Māori language]], and means "peaks on the back".<ref name="KCC">{{cite web | title=The Tuatara| work =Kiwi Conservation Club: Fact Sheets| publisher =Royal Forest and Bird Protection Society of New Zealand Inc.| date = 2007 |url=http://www.kcc.org.nz/animals/tuatara.asp| accessdate=2007-06-02}}</ref> As with many other Māori loanwords, the plural form is now generally the same as the singular in formal New Zealand English usage. "Tuataras" remains common in less formal speech, particularly among older speakers.
==Taxonomy and evolution==
Tuatara, and their sister group [[Squamata]] (which includes lizards, snakes and [[amphisbaenia]]ns), belong to the superorder [[Lepidosauria]], the only surviving taxon within [[Lepidosauromorpha]]. Squamates and tuatara both show caudal autotomy (loss of the tail-tip when threatened), and have a transverse cloacal slit.<ref name=encyclo>Cree, Alison. 2002. ''Tuatara.'' In: Halliday, Tim and Adler, Kraig (eds.), ''The new encyclopedia of reptiles and amphibians'', Oxford University Press, Oxford, pp. 210-211. ISBN 0-19-852507-9 </ref> The origin of the tuatara probably lies close to the split between the Lepidosauromorpha and the [[Archosauromorpha]]. Though tuatara resemble lizards, the similarity is superficial, since the family has several characteristics unique among [[reptile]]s. The typical lizard shape is very common for the early [[amniotes]]; the oldest known fossil of a reptile, the ''[[Hylonomus]]'', resembles a modern lizard.<ref>{{cite web| title =''Hylonomus lyelli''| work = Symbols| publisher =Province of Nova Scotia| date =May, 2003| url =http://www.gov.ns.ca/legislature/HOUSE_OF_ASSEMBLY/Symbols/fossil.htm| accessdate =2007-05-24}}</ref>
[[Image:Tuatara cladogram.svg|thumb|left|[[Cladistics|Cladogram]] showing relationships of extant members of the Sauria.<ref>Fry B.G., Vidal N., Norman J.A., Vonk F.J., Scheib H., Ramjan R., Kuruppu S., Fung K., Hedges S.B., Richardson M.K., Hodgson W.C., Ignjatovic V., Summerhayes R. and Kochva E. (2005) "Early evolution of the venom system in lizards and snakes." ''Nature'' {{doi|10.1038/nature04328}} (online 17 November 2005).</ref> Numbered items are:<br>
1. Tuatara<br>
2. Lizards<br>
3. Snakes<br>
4. Crocodiles<br>
5. Birds<br>"Lizards" are [[polyphyly|polyphyletic]]. Branch lengths do not indicate divergence times.]]
Tuatara were originally classified as lizards in 1831 when the [[British Museum]] received a skull.<ref>{{Harvnb|Lutz|2005|p=42}}.</ref> The genus remained misclassified until 1867, when [[Albert C. L. G. Günther|Albert Günther]] of the British Museum noted features similar to birds, turtles and crocodiles. He proposed the order Rhynchocephalia (meaning "beak head") for the tuatara and its fossil relatives.<ref>{{Harvnb|Lutz|2005|p=43}}.</ref> Now, most authors prefer to use the more exclusive order name of Sphenodontia for the tuatara and its closest living relatives.<ref>{{cite web| title=Lepidosauromorpha: Lizards, snakes, Sphenodon, and their extinct relatives.| work = The Tree of Life Web Project| publisher = Tree of Life Web Project | date = 1995| url=http://tolweb.org/Lepidosauromorpha/14917| accessdate=2006-07-27}} </ref>
Many disparately related species were subsequently added to the Rhynchocephalia, resulting in what taxonomists call a "[[wastebasket taxon]]".<ref name="fraser">{{cite book | author=Fraser, Nicholas; Sues, Hans-Dieter; (eds) | title="Phylogeny" In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods | publisher=Cambridge University Press | year=1994 | id=ISBN 0-521-45242-2}}</ref> [[Samuel Wendell Williston|Williston]] proposed the Sphenodontia to include only tuatara and their closest fossil relatives in 1925.<ref name="fraser" /> ''Sphenodon'' is derived from the [[List of Greek words with English derivatives|Greek]] for "wedge" (''sphenos'') and "tooth" (''odon(t)'').<ref>{{cite web| title ="Sphenodon"| work =Dictionary.com Unabridged (v 1.1)| publisher =Random House, Inc| url =http://dictionary.reference.com/browse/sphenodon| accessdate = 2007-01-08}}</ref>
Tuatara have been referred to as [[living fossil]]s.<ref name="TerraNature">{{cite web |publisher=[[TerraNature]]| title=Tuatara| work =New Zealand Ecology: Living Fossils| publisher =TerraNature Trust| date = 2004| url=http://www.terranature.org/tuatara.htm | accessdate=2006-11-10}}</ref> This means that they have remained mostly unchanged throughout their entire history, which is approximately 220 million years.<ref name="dallas">{{cite web | last=Russell| first=Matt | title= Tuatara, Relics of a Lost Age | work = Cold Blooded News| publisher= Colorado Herpetological Society| date=August, 1998 | url=http://webspinners.com/coloherp/cb-news/archive/nature/tuatara.php | accessdate=2006-05-19}}</ref> However, [[Taxonomy|taxonomic]] work<ref>{{cite book | author=Wu, Xiao-Chun | title="Late Triassic-Early Jurassic sphenodontians from China and the phylogeny of the Sphenodontia" in Nicholas Fraser & Hans-Dieter Sues (eds) In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods | publisher=Cambridge University Press | year=1994 | id=ISBN 0-521-45242-2}}</ref> on Sphenodontia has shown that this group has undergone a variety of changes throughout the [[Mesozoic]], and a recent molecular study showed that their rate of molecular evolution is faster than of any other animal so far examined.<ref>{{cite web|url=http://www.massey.ac.nz/massey/about-us/news/article.cfm?mnarticle=tuatara-evolving-faster-than-any-other-species-01-03-2008|title=Tuatara evolving faster than any other species|publisher=[[Massey University]]}}</ref><ref>{{cite web|url=http://www.livescience.com/animals/080326-fastest-tuatara.html|title=Fastest Evolving Creature is 'Living Dinosaur'|publisher=LiveScience|date=[[26 March]] [[2008]]}}</ref> Many of the niches occupied by [[lizards]] today were then held by sphenodontians. There was even a successful group of aquatic sphenodontians known as [[Pleurosaurus|pleurosaurs]], which differed markedly from living tuatara. Tuatara show cold weather adaptations that allow them to thrive on the islands of New Zealand; these adaptations may be unique to tuatara since their sphenodontian ancestors lived in the much warmer climates of the [[Mesozoic]].
There are two extant species: ''Sphenodon punctatus'' and the much rarer ''Sphenodon guntheri'', or Brothers Island tuatara, which is confined to [[The Brothers, New Zealand|North Brother Island]] in [[Cook Strait]].<ref name="BBC">
{{cite web | title=Tuatara - ''Sphenodon punctatus'' | work =Science and Nature: Animals | publisher = bbc.co.uk| url=http://www.bbc.co.uk/nature/wildfacts/factfiles/3052.shtml | accessdate=2006-02-28 }}</ref> The species name ''punctatus'' is [[latin language|Latin]] for "spotted",<ref>{{cite book| last =Stearn| first =William T| title =Botanical Latin| publisher =Timber Press Inc| date =April 1, 2004| location =Portland, Oregon| pages =p. 476| url =http://books.google.com/books?id=w0hZvTFJUioC&pg=PA476&lpg=PA476&dq=botanical+epithets+punctatus&source=web&ots=9qBJXCKdot&sig=bk7NNo-DkKk_UeUiOCnUj8R-4CA| id = ISBN 0881926272 }}</ref> and ''guntheri'' refers to [[Albert Günther]]. ''S. punctatus'' was named when only one species was known, and its name is misleading, since both species can have spots. The Brother's Island tuatara (''S. guntheri'') has olive brown skin with yellowish patches, while the colour of the other species, (''S. punctatus''), ranges from olive green through grey to dark pink or brick red, often mottled, and always with white spots.<ref name="karori"/><ref name=encyclo /><ref name=lutz16>{{Harvnb|Lutz|2005|p=16}}.</ref> In addition, ''S. guntheri'' is considerably smaller.<ref name="NZRG">Gill, Brian & Whitaker, Tony. 1996. ''New Zealand Frogs and reptiles.'' David Bateman publishing, pp. 22-24. ISBN 1869532643</ref>
''Sphenodon punctatus'' is further divided into two subspecies: the Cook Strait tuatara (unnamed subspecies), which lives on other islands in and near Cook Strait, and the northern tuatara (''Sphenodon punctatus punctatus''), which lives on the [[Bay of Plenty]], and some islands further north.<ref name="DoC"/>
A third, extinct species of ''Sphenodon'' was identified in November 1885 by William Colenso, who was sent an incomplete [[sub-fossil]] specimen from a local coal mine. Colenso named the new species ''S. diversum''.<ref name="colenso1885">{{cite journal | author=Colenso, W. | year=1885 | title=Notes on the Bones of a Species of ''Sphenodon'', (''S. diversum'', Col.,) apparently distinct from the Species already known. | journal=Transactions and Proceedings of the Royal Society of New Zealand | volume=18 | pages=118–128 | url=http://rsnz.natlib.govt.nz/volume/rsnz_18/rsnz_18_00_000850.pdf }}</ref>
==Description==
[[Image:Tuatara scale.png|thumb|right|100px|Size comparison of male ''S. punctatus'' and human.]]
The tuatara is considered the most unspecialised living [[amniote]]; the brain and mode of locomotion resemble that of amphibians and the heart is more primitive than any other reptile.<ref name="dallas"/>
Both species are [[sexual dimorphism|sexually dimorphic]], males being larger.<ref name=encyclo /> Adult ''S. punctatus'' males measure 61 cm (24 in) in length and females 45 cm (18 in).<ref name=encyclo /> The San Diego Zoo even cites a length of up to 80 cm (31 in).<ref>{{cite web |publisher=[[San Diego Zoo]] |url=http://www.sandiegozoo.org/animalbytes/t-tuatara.html |title=San Diego Zoo's Animal Bytes: Tuatara |format= |work= |accessdate=2008-04-19}}</ref> Males weigh up to 1 kg (2.2 lb), and females up to 0.5 kg (1.1 lb).<ref name=encyclo /> Brother's Island tuatara are slightly smaller, weighing up to 660 g (1.3 lb).<ref name="NZRG">Gill, Brian & Whitaker, Tony. 1996. ''New Zealand Frogs and reptiles.'' David Bateman publishing, pp. 22-24. ISBN 1869532643</ref>
The tuatara's greenish brown colour matches its environment, and can change over its lifetime, since tuatara shed their skin at least once per year as adults,<ref name=lutz16>{{Harvnb|Lutz|2005|p=16}}.</ref> and three or four times a year as juveniles. Tuatara sexes differ in more than size. The spiny crest on a tuatara's back, made of triangular soft folds of skin, is larger in males, and can be stiffened for display. The male abdomen is narrower than the female's.<ref>{{cite web |url=http://www.animalcorner.co.uk/reptiles/rep_tuatara.html |title=Tuataras at Animal Corner |accessdate=2007-12-31 |format= |work=}}</ref>
[[Image:Tuatara skull side.PNG|thumb|200px|left|Skull of a tuatara, showing the complete temporal arches, and individual bones:<br>
1 = premaxilla<br>
2 = nasal<br>
3 = prefrontal<br>
4 = frontal<br>
5 = maxilla<br>
6 = postfrontal<br>
7 = dental<br>
8 = postorbital<br>
9 = jugal<br>
10 = parietal<br>
11 = squamosal<br>
12 = quadrate]]
===Skull===
In the course of evolution, the skull has been modified in most diapsids from the original version evident in the fossil record. However, all the original features are preserved in that of the tuatara; it has two openings (''temporal fenestra'') on each side of the skull, with complete arches. In addition, the upper jaw is firmly attached to the skull.<ref name=encyclo /> This makes for a very rigid, inflexible construction. [[Testudines]] ([[turtle]] and [[tortoise]]) skulls with their single temporal fenestra are widely considered to be the most primitive among amniotes, though there is evidence they may have lost the temporal holes rather than never having had them.<ref name=encyclo /><ref name="rieppel&debraga1996">Rieppel, O., and DeBraga, M. (1996). "Turtles as diapsid reptiles." ''Nature'', '''384''': 453-455.</ref><ref name="zardoya&meyer1998">Zardoya, R., and Meyer, A. (1998). "Complete mitochondrial genome suggests diapsid affinities of turtles." ''Proceedings of the National Academy of Sciences of the United States of America'', '''95'''(24): 14226-14231.</ref>
The tip of the upper jaw is beak-like and separated from the remainder of the jaw by a notch. There is a single row of teeth in the lower jaw and a double row in the upper, with the bottom row fitting perfectly between the two upper rows when the mouth is closed.<ref name=encyclo /> This tooth arrangement is not seen in any other reptile; although most [[snake]]s have a double row of teeth in their upper jaw, their arrangement and function is different from the tuatara's. The jaws, joined by [[ligament]], chew with backwards and forwards movements combined with a shearing up and down action. The force of the bite is suitable for shearing [[chitin]] and bone.<ref name=encyclo /> The tuatara's teeth are not replaced, since they are not separate structures like real teeth, but sharp projections of the jaw bone.<ref name=lutzp27>{{Harvnb|Lutz|2005|p=27}}.</ref> As their teeth wear down, older tuatara have to switch to softer prey such as [[earthworm]]s, [[larva]]e, and [[slug]]s, and eventually have to chew their food between smooth jaw bones.<ref>{{cite web| last =Mlot| first =Christine| title =Return of the Tuatara:A relic from the age of dinosaurs gets a human assist| work =Science News| publisher =Science News| date =1997-11-08| url =http://www.sciencenews.org/pages/pdfs/data/1997/152-19/15219-21.pdf| accessdate =2007-05-24}}</ref>
===Sensory organs===
Both eyes can [[Accommodation (eye)|focus]] independently, and are specialized with a "duplex retina" that contains two types of visual cells for both day and night vision, and a [[tapetum lucidum]] which reflects on to the retina to enhance vision in the dark. There is also a third eyelid on each eye, the [[nictitating membrane]].
The tuatara has a third eye on the top of its head called the [[parietal eye]]. It has its own lens, cornea, [[retina]] with rod-like structures and degenerated nerve connection to the brain, suggesting it evolved from a real eye. The parietal eye is only visible in hatchlings, which have a translucent patch at the top centre of the skull. After four to six months it becomes covered with opaque scales and pigment.<ref name=encyclo /> Its purpose is unknown, but it may be useful in absorbing [[ultraviolet]] rays to manufacture [[vitamin D]],<ref name="KCC"/> as well as to determine light/dark cycles, and help with [[thermoregulation]].<ref name=encyclo /> Of all extant tetrapods, the parietal eye is most pronounced in the tuatara. The parietal eye is part of the pineal complex, another part of which is the [[pineal gland]], which in tuatara secretes melatonin at night.<ref name=encyclo /> It has been shown that some salamanders use their pineal body to perceive polarised light, and thus determine the position of the sun, even under cloud cover, aiding navigation.<ref>Halliday, Tim R. 2002. ''Salamanders and newts: Finding breeding ponds.'' In: Halliday, Tim and Adler, Kraig (eds.), ''The new encyclopedia of reptiles and amphibians'', Oxford University Press, Oxford, p. 52. ISBN 0-19-852507-9 </ref>
Together with [[turtle]]s, the tuatara has the most primitive hearing organs among the amniotes. There is no [[eardrum]] and no earhole,<ref name=lutzp27>{{Harvnb|Lutz|2005|p=27}}.</ref> and the [[middle ear]] cavity is filled with loose tissue, mostly [[adipose tissue]]. The [[stapes]] comes into contact with the [[Quadrate bone|quadrate]] (which is immovable) as well as the [[hyoid bone|hyoid]] and [[squamosal]]. The [[hair cell]]s are unspecialized, innervated by both [[Afferent nerve|afferent]] and [[efferent nerve]] fibres, and respond only to low frequencies. Even though the hearing organs are poorly developed and primitive with no visible external ears, they can still show a frequency response from 100-800 [[Hertz|Hz]], with peak sensitivity of 40 [[Decibel|dB]] at 200 Hz.<ref>{{cite web | last=Kaplan | first=Melissa | title= Reptile Hearing | publisher=Melissa Kaplan's Herp Care Collection| date=[[2003-09-06]] | url=http://www.anapsid.org/reptilehearing.html | accessdate=2006-07-24}}</ref>
===Spine and ribs===
The tuatara [[Vertebral column|spine]] is made up of hour-glass shaped amphicoelous [[vertebra]]e, concave both before and behind.<ref name=lutzp27>{{Harvnb|Lutz|2005|p=27}}.</ref> This is the usual condition of fish vertebrae and some amphibians, but is unique to tuatara within the [[amniotes]].
The tuatara has [[gastralium|gastralia]], rib-like bones also called gastric or abdominal ribs,<ref>{{cite web | url=http://www.aquarium-berlin.de/en/experience/animal-highlights/tuatara.html | accessdate=2007-09-11 | title=Zoo Berlin: Tuatara}}</ref> the presumed ancestral trait of diapsids. They are found in some [[lizard]]s, where they are mostly made of cartilage, as well as crocodiles and the tuatara, and are not attached to the spine or thoracic ribs. The true ribs are small projections, with small, hooked bones, called uncinate processes, found on the rear of each rib.<ref name=lutzp27>{{Harvnb|Lutz|2005|p=27}}.</ref> This feature is also present in birds. The tuatara is the only living [[tetrapod]] with well developed gastralia and uncinate processes.
In the early tetrapods, the gastralia and ribs with uncinate processes, together with bony elements such as bony plates in the skin (osteoderms) and [[clavicle]]s (collar bone), would have formed a sort of exo-skeleton around the body, protecting the belly and helped to hold in the guts and inner organs. These anatomical details most likely evolved from structures involved in locomotion even before the vertebrates ventured onto land. The gastralia may have been involved in the breathing process in early amphibians and reptiles. The pelvis and shoulder girdles are arranged differently to those of lizards, as is the case with other parts of the internal anatomy and its scales.<ref>{{cite web |url=http://nzphoto.tripod.com/animal/tuatara.htm |title=Tuatara Reptile, New Zealand |accessdate=2007-12-31 |format= |work=}}</ref>
{{-}}
==Behaviour==
Adult tuatara are [[Landform|terrestrial]] and [[nocturnal]] reptiles, though they will often bask in the sun to warm their bodies. Hatchlings hide under logs and stones, and are [[Diurnal animal|diurnal]], likely because adults are cannibalistic. Tuatara thrive in temperatures much lower than those tolerated by most reptiles, and [[hibernation|hibernate]] during winter.<ref>{{cite web| title =Tuatara: Facts| publisher =Southland Museum| date =January 18, 2006| url =http://web.archive.org/web/20070609034405/http://www.southlandmuseum.com/tuatara_-_facts.htm| accessdate = 2007-06-02}}</ref> They can maintain normal activities at temperatures as low as {{convert|7|°C|°F|sigfig=1}}, while temperatures over {{convert|28|°C|°F|sigfig=2}} are generally fatal. The optimal body temperature for the tuatara is from 16 to 21 °C (60-70 °C), the lowest of any reptile.<ref name="UofM">{{cite web| last =Musico| first =Bruce| title =''Sphenodon punctatus''| work =Animal Diversity Web| publisher =University of Michigan Museum of Zoology| date =1999| url =http://animaldiversity.ummz.umich.edu/site/accounts/information/Sphenodon_punctatus.html| accessdate =2006-04-22 }}</ref> The body temperature of tuatara is lower than that of other reptiles ranging from 5.2–11.2 °C (41-52 °F) over a day, whereas most reptiles have body temperatures around {{convert|20|°C|°F|sigfig=2}}.<ref>{{cite journal | author = Thompson MB and Daugherty CH | year = 1998 | title = Metabolism of tuatara, ''Sphenodon punctatus'' | journal = Comparative biochemistry and physiology A | volume = 119 | pages = 519–522 | doi=10.1016/S1095-6433(97)00459-5}}</ref> The low body temperature results in a slower [[metabolism]].
Burrowing seabirds such as [[petrel]]s, [[prion (bird)|prion]]s and [[shearwater]]s share the tuatara's island habitat during the bird's nesting season. The tuatara use the [[bird]]'s burrows for shelter when available, or dig their own. The seabirds' [[guano]] helps to maintain invertebrate populations that tuatara predominantly prey on; including [[beetle]]s, [[cricket]]s and [[spider]]s. Their diet also consists of [[frog]]s, [[lizard]]s and bird's eggs and chicks. The eggs and young of seabirds that are seasonally available as food for tuatara may provide [[essential fatty acid|beneficial fatty acids]].<ref name=encyclo /> Tuatara will bite when approached, and do not let go easily.<ref name=lutz24>{{Harvnb|Lutz|2005|p=24}}.</ref> They can, however, be easily caught by lowering a tennis ball attached to a length of plastic into their burrow, and slowly retrieving the ball with the tuatara attached.<ref name=lutz24>{{Harvnb|Lutz|2005|p=24}}.</ref>
[[Image:Brueckenechse.jpg|thumb|right|190px|Tuatara juvenile (''Sphenodon punctatus'')]]
Tuatara reproduce very slowly, taking ten years to reach sexual maturity. Mating occurs in midsummer; females mate and lay [[Egg (biology)|egg]]s once every four years.<ref>{{cite journal| author = Cree et al| year = 1992 | title = Reproductive cycles of male and female tuatara (''Sphenodon punctatus'') on Stephens Island, New Zealand| journal = Journal of Zoology| volume = 226| pages = 199–217}}</ref> During courtship, a male makes his skin darker, raises his crests and parades toward the female. He slowly walks in circles around the female with stiffened legs. The female will either submit, and allow the male to mount her, or retreat to her burrow. <ref> {{cite journal | author=C. Gand, J.C. Gillingham and D.L. Clark | year = 1984 | title = Courtship, mating and male combat in Tuatara, ''Sphenodon punctatus'' | journal = Journal of Herpetology | volume = 18(2) | pages = 194–197 | doi=10.2307/1563749}}</ref> Males do not have a [[penis]]; they reproduce by the male lifting the tail of the female and placing his vent over hers. The [[sperm]] is then transferred into the female, much like the mating process in birds.<ref>{{Harvnb|Lutz|2005|p=19}}.</ref>
Tuatara eggs have a soft, parchment-like shell. It takes the females between one and three years to provide eggs with yolk, and up to seven months to form the shell. It then takes between 12 and 15 months from copulation to hatching. This means reproduction occurs at 2 to 5 year intervals, the slowest in any reptile.<ref name=encyclo /> The sex of a hatchling depends on the temperature of the egg, with warmer eggs tending to produce male tuatara, and cooler eggs producing females. Eggs incubated at {{convert|21|°C|°F|sigfig=2}} have an equal chance of being male or female. However, at {{convert|22|°C|°F|sigfig=2}}, 80% are likely to be males, and at {{convert|20|°C|°F|sigfig=2}}, 80% are likely to be females; at {{convert|18|°C|°F|sigfig=2}} all hatchlings will be females.<ref name="KCC" /> There is some evidence that sex determination in tuatara is determined by both genetic and environmental factors.<ref>Cree, A., Thompson, M. B. & Daugherty, C. H. 1995. Tuatara sex determination. ''Nature'' '''375''', 543. {{doi|10.1038/375543a0}}</ref>
Tuatara probably have the slowest growth rates of any reptile,<ref name=encyclo /> continuing to grow larger for the first 35 years of their lives.<ref name="KCC"/> The average lifespan is about 60 years, but they can live to be over 100 years old.<ref name="KCC"/>
==Conservation==
[[Image:North Island Map tuatara.PNG|thumb|left|Current distribution of tuatara (in black).<ref>Daugherty, C. H., A. Cree, J. M. Hay & M. B. Thompson. 1990. Neglected taxonomy and continuing extinctions of tuatara ''(Sphenodon)''. ''Nature'' '''347''', 177-179. {{doi|10.1038/347177a0}}</ref><ref name=recovery>{{cite web| last =Gaze| first =Peter| title =Tuatara recovery plan 2001-2011| work =Threatened Species Recovery Plan 47| publisher =Biodiversity Recovery Unit, Department of Conservation, Government of New Zealand| date =2001| url =http://www.doc.govt.nz/upload/Conservation/PDF/Tuatara-Recovery-Plan.pdf| accessdate = 2007-06-02}} ISBN 0478221312</ref><ref>{{cite web | url=http://www.tiritirimatangi.org.nz/Articles/NZ%20Herald%20Articles%20-%20Tuatara%20Release.pdf | date=[[2003-10-25]] | author=Beston, Anne | title=New Zealand Herald: Tuatara Release | accessdate = 2007-09-11}}</ref> Circles represent the North Island tuatara, squares the Brothers Island tuatara. Symbols may represent up to seven islands.]]
===Distribution and threats===
Tuatara were long confined to 32 offshore islands free of mammals.<ref name="DoC"/> The islands are difficult to get to,<ref>{{Harvnb|Lutz|2005|pp=59-60}}.</ref> and are colonised by few animal species, indicating that some animals absent from these islands may have caused tuatara to disappear from the mainland. However, kiore ([[Polynesian rat]]s) had recently established on several of the islands, and tuatara were persisting, but not breeding, on these islands.<ref>Crook, I. G. 1973. The tuatara, ''Sphenodon punctatus'' Gray, on islands with and without populations of the Polynesian rat, ''Rattus exulans'' (Peale). Proceedings of the New Zealand Ecological Society 20:115-120.</ref><ref name=cree_etal1995>Cree, A., Daugherty, C.H. and Hay, J.M. 1995. Reproduction of a rare New Zealand reptile, the tuatara Sphenodon punctatus, on rat-free and rat-inhabited islands. Conservation Biology 9, 373-383.{{doi|10.1046/j.1523-1739.1995.9020373.x}}</ref> Additionally, tuatara were much rarer on the rat-inhabited islands.<ref name=cree_etal1995 />
===Eradication of rats===
Tuatara were removed from Stanley, Red Mercury and Cuvier Islands in 1990 and 1991, and maintained in captivity to allow Polynesian rats to be eradicated on those islands. All three populations bred in captivity, and after successful eradication, all individuals including the new juveniles were returned to their islands of origin. In the 1991/92 season, Little Barrier Island was found to hold only eight tuatara, which were taken into ''[[in situ conservation|in situ]]'' captivity, where females produced 42 eggs, which were incubated at Victoria University. The resulting offspring were subsequently held in an enclosure on the island. The 2001-2011 Recovery Plan, published in 2001, states that eradication of rats from this island is pending.<ref name=recovery />
Pacific rats were eradicated on Middle Chain Island in 1992, Whatupuke in 1993, Lady Alice Island in 1994, and Coppermine Island in 1997. Following this program, juveniles have once again been seen on the latter three islands. In contrast, rats persist on Hen Island of the same group, and no juvenile tuatara had been seen there as of 2001. Middle Chain Island holds no tuatara, but it is considered possible for rats to swim between Middle Chain and other islands that do hold tuatara, and the rats were eradicated to prevent this.<ref name=recovery />
Another rodent eradication was carried out on the Rangitoto Islands east of D’Urville Island, to prepare for the release of 432 Cook Strait tuatara juveniles in 2004, which were being raised at Victoria University as of 2001.<ref name=recovery /><!--can we find out whether this plan was followed through?-->
===Introductions===
[[Image:Tuatara karori head.jpg|thumb|right|Tuatara at the [[Karori Wildlife Sanctuary]] are given coloured markings on the head for identification.]]
====Brothers Island tuatara====
''Sphenodon guntheri'' is present naturally on one small island with a population of approximately 400. In 1995, 50 juvenile and 18 adult Brothers Island tuatara were moved to Titi Island in Cook Strait, and their establishment monitored. Two years later, more than half of the animals had been re-sighted and all but one had gained weight. In 1998, 34 juveniles from captive breeding and 20 wild caught adults were similarly transferred to Matiu Island, a more publicly accessible location. The captive juveniles were from induced layings from wild females.<ref name=recovery />
In late October 2007, it was announced that 50 tuatara collected as eggs from North Brother Island and hatched at Victoria University were being released onto Long Island in Cook Strait. The animals had been cared for at Wellington Zoo for the last five years and have been kept in secret in a specially built enclosure at the zoo, off display.<ref>{{cite press release | title = Rare tuatara raised at Wellington Zoo | publisher = [[Wellington Zoo]] | date = 2007-10-29 | url = http://www.scoop.co.nz/stories/SC0710/S00061.htm |accessdate = 2008-04-19}}</ref>
====Northern tuatara====
''Sphenodon punctatus'' naturally occurs on 29 islands and its population is estimated to be over 60,000 individuals.<ref name=encyclo />
In 1996, 32 adult northern tuatara were moved from Moutoki Island to Moutohora. The carrying capacity of Moutohora is estimated at 8500 individuals, and the island could allow public viewing of wild tuatara.<ref name=recovery />
A mainland release of ''S. punctatus'' occurred in 2005 in the heavily fenced and monitored [[Karori Wildlife Sanctuary]].<ref name="karori"/> The second mainland release took place in October 2007, when a further 130 were transferred from Stephens Island to the Karori Sanctuary.<ref>{{cite news|url=http://www.stuff.co.nz/stuff/4243952a7693.html|title=130 Tuatara Find Sanctuary|publisher=[[The Dominion Post]]|date=2007-10-20|accessdate=2008-04-19}}</ref>
===Captive breeding===
There are several tuatara breeding programmes within New Zealand. [[southland museum and art gallery|Southland Museum and Art Gallery]] in [[Invercargill]], was the first to have a tuatara breeding programme; they breed ''Sphenodon punctatus''. [[Hamilton Zoo]] and [[Wellington Zoo]] also breed tuatara for release into the wild. The [[Victoria University of Wellington]] maintains a research programme into the captive breeding of tuatara, and the [[Mt Bruce Wildlife Centre|Pukaha Mount Bruce Wildlife Centre]] keeps a pair and a juvenile. The WildNZ Trust has a tuatara breeding enclosure at [[Ruawai]].
==Cultural significance==
Tuatara feature in a number of indigenous legends, and are held as ''ariki'' (God forms). Tuatara are regarded as the messengers of [[Whiro]], the [[deity|god]] of death and disaster, and Māori women are forbidden to eat them.<ref>{{cite web| last =Williams| first =David| title =Chapter 6: Traditional Kaitiakitanga Rights and Responsibilities| work =Wai 262 Report: Matauranga Maori and Taonga| publisher =Waitangi Tribunal| date =2001| url =http://www.waitangi-tribunal.govt.nz/doclibrary/public/wai262/matauranga_maori/Chapt06.pdf| accessdate = 2007-06-02}}</ref> Tuatara also indicate ''tapu'' (the borders of what is sacred and restricted),<ref name=ramdstad>Kristina M. Ramstad, N. J. Nelson, G. Paine, D. Beech, A. Paul, P. Paul, F. W. Allendorf, C. H. Daugherty (2007) Species and Cultural Conservation in New Zealand: Maori Traditional Ecological Knowledge of Tuatara. ''Conservation Biology'' 21 (2), 455–464. {{doi|10.1111/j.1523-1739.2006.00620.x}}</ref> beyond which there is ''mana'', meaning there could be serious consequences if that boundary is crossed.<ref name=ramdstad /> Māori women would sometimes tattoo images of lizards, some of which may represent tuatara, near their genitals.<ref name=ramdstad /> Today, tuatara are regarded as a ''[[taonga]]'' (special treasure).<ref>{{Harvnb|Lutz|2005|p=64}}.</ref>
The tuatara was featured on one side of the [[Coins of the New Zealand dollar#Past Coinage|New Zealand 5 cent coin]], which was phased out in October 2006. ''Tuatara'' was also the name of the Journal of the Biological Society of Victoria University College and subsequently [[Victoria University of Wellington]], published from 1947 until 1993.<ref>{{cite web |publisher=New Zealand Electronic Text Centre |url=http://www.nzetc.org/tm/scholarly/tei-corpus-tuatara.html |title=Tuatara : Journal of the Biological Society |format= |work= |accessdate=2008-04-19}}</ref>
==References== <!-- MusTexasTechUnivOccasPap178:1 -->
{{reflist|2}}
==Bibliography==
*{{Harvard reference| Surname = Lutz| Given = Dick| Year = 2005| Title = Tuatara: A Living Fossil| Publisher = Salem, Oregon: DIMI PRESS| ID = ISBN 0-931625-43-2}}
*{{cite book | last=McKintyre | first=Mary | year=1997 | title=Conservation of the Tuatara | publisher=Victoria University Press | id=ISBN 0-86473-303-8 }}
*{{Harvard reference| Surname = Newman| Given = D. G.| Year = 1987| Title = Tuatara. Endangered New Zealand Wildlife Series| Publisher = Dunedin, New Zealand: John McIndoe| ID = ISBN 0868680982}}
*{{cite book | last=Parkinson | first=Brian | year=2000 | title=The Tuatara | publisher=Reed Children’s Books | id=ISBN 1-86948-831-8}}
==External links==
{{commons|Sphenodon punctatus}}
{{wikispecies|Sphenodon}}
*{{cite web |url = http://www.doc.govt.nz/upload/documents/science-and-technical/TSOP21.pdf | title = Tuatara captive management plan and husbandry manual | B. Blanchard et al. | 2000 | publisher = Department of Conservation, Wellington, New Zealand | format = PDF | accessdate = 2007-11-26}}
*{{cite web | url=http://digimorph.org/specimens/Sphenodon_punctatus/adult/ | title=Digimorph - ''Sphenodon punctatus'' (tuatara) - 3D visualisations from X-ray CT scans | accessdate=2006-05-08}}
*{{cite web | title=ARKive - images and movies of the Brothers Island tuatara ''(Sphenodon guntheri)'' | url=http://www.arkive.org/species/GES/reptiles/Sphenodon_guntheri/ | accessdate=2007-06-03}}
*{{cite web | title=Evolution of a third eye in some animals? ''MadSci Network'' | url=http://www.madsci.org/posts/archives/2005-07/1121008231.Zo.r.html | accessdate=2007-08-09}}
*{{cite web | title=The Lonely Eye | url=http://bjo.bmjjournals.com/cgi/content/full/89/3/256 | accessdate=2006-10-11}}
==Institutions that keep tuatara==
{{col-begin}}
{{col-2}}
'''New Zealand'''
*[http://www.aucklandzoo.co.nz/conservation/index.php#proj Auckland Zoo]
*[http://www.hamiltonzoo.co.nz/index.asp?PageID=2145828546 Hamilton Zoo Tuatara breeding]
*[http://www.natureland.co.nz/animals.asp Natureland Zoo, Nelson, NZ]
*[http://www.mtbruce.org.nz/tuatara_more.htm Pukaha Mount Bruce]
*[http://www.kiwibird.co.nz/kiwi/gallery/index.cfm/?pluginAction=image&slideshowID=1&imageID=35 Kiwi Birdlife Park Queenstown]
*[http://web.archive.org/web/20070617025329/http://www.southlandmuseum.com/tuatara_-_breeding.htm Southland Museum and Art Gallery]
*[http://www.kcc.org.nz/animals/tuatara/conservation.asp Victoria University of Wellington]
*[http://www.wellingtonzoo.com/animals/animals/reptiles/tuatara.html Wellington Zoo]
*[http://www.wildnz.org/?p=projects WildNZ Trust Projects at Ruawai]
{{col-2}}
'''Australia'''
*[http://www.aussiepythons.com/gallery2.php?g2_itemId=56542 Taronga Zoo]
'''Europe'''
*[http://www.chesterzoo.org/AnimalsandPlants/Reptiles/Tuatara.aspx Chester Zoo]
*[http://www.aquarium-berlin.de/en/experience/animal-highlights/tuatara.html Zoo Aquarium Berlin]
'''United States'''
*[http://www.dallaszooed.com/animalfacts/animalfacts.php?id=110&name=TUV&ci=5&li=8 Dallas Zoo]
*[http://www.stlzoo.org/animals/abouttheanimals/reptiles/tuataras/tuatara.htm Saint Louis Zoo]
*[http://www.sandiegozoo.org/animalbytes/t-tuatara.html San Diego Zoo] ''(S. guntheri)''
*[http://www.toledoblade.com/apps/pbcs.dll/article?AID=/20060310/NEWS38/%20603100383/-1/NEWS Toledo Zoo]
{{col-end}}
[[Category:Sphenodontia]]
[[Category:Living fossils]]
[[Category:Reptiles of New Zealand]]
[[ca:Tuatara]]
[[cs:Hatérie novozélandská]]
[[de:Brückenechsen]]
[[es:Sphenodon]]
[[fr:Sphénodon]]
[[ko:투아타라]]
[[hr:Premosnici]]
[[it:Sphenodon]]
[[he:ספנודון]]
[[lt:Tuataros]]
[[li:Brögkherdisse]]
[[ml:ടുവാടര]]
[[nl:Brughagedissen]]
[[ja:ムカシトカゲ]]
[[pl:Hatteria]]
[[pt:Tuatara]]
[[ru:Гаттерия]]
[[simple:Tuatara]]
[[fi:Tuatara]]
[[tr:Tuatara]]
[[zh:喙頭蜥]]