AnimalTracks.wiki

What the sources say

TuataraSphenodon punctatus

Every figure, record and mechanism on the Tuatara profile was written from a source, and this is the working table behind it: 64 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

Profile updated

Source
01

New Zealand Department of Conservation

Tuatara. New Zealand Department of Conservation.

The page saysusually shared with colonies of breeding seabirds
The source saysThe islands are usually occupied by colonies of breeding seabirds.
The page saysMostly beetles, wētā, worms, millipedes and spiders, with the rest made up of lizards, seabird eggs and chicks
The source saysTheir diet consists primarily of invertebrates, such as: beetles wētā worms millipedes and spiders. The remainder of what they eat is made up of lizards, seabird eggs and chicks.
The page saysAdult males are about half a metre long and weigh up to 1.5 kilograms when fully grown
The source saysAdult males are about 0.5 metres in length, and weigh up to 1.5 kg when fully grown.
The page saysa crest of spines along the neck and down the back that a male can raise to attract females or when fighting other males
The source saysThe male has a distinctive crest of spines running along the neck and down the back. He can erect these spines to attract females or when fighting with other males.
The page saysA tuatara keeps growing until it is about 35 years old
The source saysThey keep growing until they are about 35 years old.
The page saysits average life span is about 60 years, though it can live up to 100
The source saysA tuatara's average life span is about 60 years, but they can live up to 100 years.
The page saysThe diet is mostly invertebrates such as beetles, wētā, worms, millipedes and spiders, and the rest is lizards, seabird eggs and chicks
The source saysTheir diet consists primarily of invertebrates, such as: beetles wētā worms millipedes and spiders. The remainder of what they eat is made up of lizards, seabird eggs and chicks.
The page saysIn the wild, tuatara now survive on only 32 islands
The source saysTuatara once lived throughout mainland New Zealand but now only survive in the wild on 32 islands.Note: current DOC web page; the 2020 genome paper and 2017 abstract also give 32 islands
The page saysRats are considered their most serious threat
The source saysRats are considered the most serious threat to the survival of tuatara
The page saysthere were probably few, if any, tuatara left on the North and South Islands by the time European settlers arrived
The source saysThere were probably few, if any, tuatara left on the North and South Islands by the time European settlers arrived in New Zealand.
The page saysthat was dropped in 2009
The source saysA second species Sphenodon guntheri was recognised in 1989 but discontinued in 2009 when research concluded tuatara is best described as one species.
The page saysputs the average at about 60 years, with a maximum of up to 100
The source saysA tuatara's average life span is about 60 years, but they can live up to 100 years.
The page saystuatara have one of the slowest growth rates of any reptile
The source saysTuatara have one of the slowest growth rates of any reptile.
The page sayskeeps growing until it is about 35 years old
The source saysThey keep growing until they are about 35 years old.
The page saysone of the slowest growth rates of any reptile.
The source saysTuatara have one of the slowest growth rates of any reptile.

Source
02

San Diego Zoo Wildlife Alliance

Tuatara. San Diego Zoo Wildlife Alliance.

The page saysa nocturnal New Zealand islander
The source saysunlike lizards, tuataras are nocturnal
The page saysa light-sensitive third eye it does not see with
The source saysThe unique eye is sensitive to light
The page saysA light-sensitive third eye with a retina and lens
The source saysThe "eye" has a retina, lens, and nerve endings, yet it is not used for seeing.
The page saysIt looks like a lizard, but it is not one
The source saysAlthough it looks like a lizard, it is really quite different.Note: not-a-lizard also follows from the genome paper's divergence of the tuatara lineage from all squamates
The page saysIn managed care, the San Diego Zoo gives a life span of up to 91 years
The source saysUp to 91 years in managed care
The page saysOn top of the head, a tuatara has a third eye with a retina, lens and nerve endings
The source saystheir most curious body part is a "third eye" on the top of the head. The "eye" has a retina, lens, and nerve endings
The page saysIt isn't used for seeing.
The source saysyet it is not used for seeing
The page saysIn young tuatara it shows through the skin, but within a few months scales and pigment cover it, making it hard to spot
The source saysIt is visible under young tuataras’ skin but becomes covered with scales and pigment in a few months, making it hard to see.
The page saysThe eye is sensitive to light and may help the tuatara judge the time of day or the season
The source saysThe unique eye is sensitive to light and may help the tuatara judge the time of day or season.
The page saysA tuatara's upper jaw carries two rows of teeth, and the one row on the lower jaw fits between them when the mouth is closed
The source saysThere are two rows of teeth on the upper jaw and one row on the lower jaw that fits between the upper rows of teeth when the mouth is closed.
The page saysLost or broken teeth are not replaced, and older tuatara have to eat softer food as their teeth wear down
The source saysThese small teeth are not replaced when lost or broken, and older tuataras have to eat softer food items as their teeth wear down.
The page saysThe Brothers Island tuatara was once treated as a second species, *Sphenodon guntheri*
The source saysit was initially decided that the Brothers Island tuatara was a separate species ( Sphenodon guntheri )
The page saysit contains a retina and a lens, but the tuatara does not use it for seeing
The source saysThe "eye" has a retina, lens, and nerve endings, yet it is not used for seeing.
The page saysIt does react to light, which may help the animal tell what time of day or season it is
The source saysThe unique eye is sensitive to light and may help the tuatara judge the time of day or season.
The page saysTwo Rows of Teeth, One Shearing Bite
The source saysThere are two rows of teeth on the upper jawNote: heading; shearing bite is claimed from the 1982 mastication abstract

Source
03

Gemmell et al. 2020

Gemmell et al. (2020). The tuatara genome reveals ancient features of amniote evolution. Nature.

The page saysThe sole survivor of an ancient reptile order
The source saysthe only living member of the reptilian order Rhynchocephalia (Sphenodontia)
The page saysthe lowest optimal body temperature of any reptile, 16 to 21 degrees Celsius
The source saysnotable for having the lowest optimal body temperature of any reptile (16–21 °C)
The page saysthe only living member of an entire reptile order, Rhynchocephalia
The source saysthe only living member of the reptilian order Rhynchocephalia (Sphenodontia)
The page saysthe tuatara lineage split from the branch that led to every living lizard and snake around 250 million years ago
The source saysthe divergence of the tuatara lineage from all squamates (lizards and snakes) during the early part of the Triassic period at about 250 million years ago
The page sayswas widespread across Gondwana
The source saysonce widespread across Gondwana
The page saysits last fossils outside New Zealand dating to about 70 million years ago
The source saysthe most recent fossil record outside of New Zealand is from Argentina in the Late Cretaceous epoch (about 70 Ma)
The page saysA 2020 genome study put the global population at around 100,000
The source saysThe current global population is estimated to be around 100,000 individuals.Note: 2020 is the reference's publication year (Gemmell et al. 2020); dated to the paper so the figure does not read as a 2026 count
The page saysLizards and snakes make up the squamates
The source saysall squamates (lizards and snakes)
The page saysdates the tuatara lineage's split from them to about 250 million years ago, early in the Triassic
The source saysthe divergence of the tuatara lineage from all squamates (lizards and snakes) during the early part of the Triassic period at about 250 million years ago
The page saysThe tuatara belongs to a separate order, Rhynchocephalia, and is its only living member
The source saysthe only living member of the reptilian order Rhynchocephalia (Sphenodontia)
The page saysa 2020 study of the tuatara genome
The source saysHere we analyse the genome of the tuataraNote: 2020 is the reference's publication year (Gemmell et al. 2020)

Source
04

Animal Diversity Web, University of Michigan

Sphenodon punctatus. Animal Diversity Web, University of Michigan.

The page saysIslands off the coast of New Zealand, generally cliff-bound and windswept
The source saysThe islands are generally cliff-bound, frequently exposed to strong winds
The page saysOn windswept islands off New Zealand
The source saysfrequently exposed to strong winds
The page saysThe tuatara has been falsely called a living fossil.
The source saysThe tuatara has been falsely called a living fossil.
The page saysIts teeth are fused to the jawbone
The source saysthe tuatara's teeth are fused to the jaw bone (acrodont tooth structure)
The page saysNobody has pinned it down
The source saysthe function has not been clearly recognized
The page saysKnown as the parietal eye
The source saysposess a "parietal eye" on the top of their head

Source
05

Meloro & Jones 2012

Meloro & Jones (2012). Tooth and cranial disparity in the fossil relatives of Sphenodon (Rhynchocephalia) dispute the persistent 'living fossil' label. Journal of Evolutionary Biology.

The page saysRhynchocephalia once held a much greater diversity of forms
The source saysthe group to which it belongs included a much greater diversity of forms in the Mesozoic
The page saysis not the product of evolutionary stasis
The source saysthe tuatara is not the product of evolutionary stasis but that it represents the only survivor of a diverse Mesozoic radiation whose subsequent decline remains to be explained
The page saysthe only survivor of a diverse Mesozoic radiation whose decline remains unexplained
The source saysrepresents the only survivor of a diverse Mesozoic radiation whose subsequent decline remains to be explained

Source
06

Herrera-Flores, Stubbs & Benton 2017

Herrera-Flores, Stubbs & Benton (2017). Macroevolutionary patterns in Rhynchocephalia: is the tuatara (Sphenodon punctatus) a living fossil? Palaeontology.

The page saysThe label has often been applied because of the tuatara's apparent close resemblance to its Mesozoic forebears
The source sayshas often been noted as a classic ‘living fossil’ because of its apparently close resemblance to its Mesozoic forebears
The page saysA 2017 study that put the label to a formal test came out in its favour
The source saysWe provide a testable definition for ‘living fossils’ based on a slow rate of lineage evolution and a morphology close to the centroid of clade morphospace.Note: 2017 is the reference's publication year (Herrera-Flores, Stubbs & Benton 2017)
The page saysthe living tuatara did evolve unusually slowly, and its anatomy sits near the centre of the range of forms seen across all Rhynchocephalia
The source saysthe extant tuatara underwent unusually slow lineage evolution, and is morphologically conservative, being located near the centre of the morphospace for all Rhynchocephalia
The page saysThe label has been disputed because the tuatara's Mesozoic relatives were widely diverse and because the living tuatara has adaptations of its own
The source saysThis designation has been disputed because of the wide diversity of Mesozoic forms and because of derived adaptations in living Sphenodon.
The page saysdefined a living fossil by a slow rate of lineage evolution and a form near the middle of its group's range
The source saysWe provide a testable definition for ‘living fossils’ based on a slow rate of lineage evolution and a morphology close to the centroid of clade morphospace.
The page saysfound the tuatara meets both tests
The source saysthe extant tuatara underwent unusually slow lineage evolution, and is morphologically conservative, being located near the centre of the morphospace for all Rhynchocephalia
The page saysA 2017 study defined a living fossil
The source saysWe provide a testable definition for ‘living fossils’Note: 2017 is the reference's publication year (Herrera-Flores, Stubbs & Benton 2017)
The page saystags: living-fossil
The source saysthe extant tuatara underwent unusually slow lineage evolution, and is morphologically conservative, being located near the centre of the morphospace for all Rhynchocephalia

Source
07

Hay et al. 2009

Hay et al. (2009). Genetic diversity and taxonomy: a reassessment of species designation in tuatara (Sphenodon: Reptilia). Conservation Genetics.

The page saysa genetic study concluded that tuatara is best described as a single species with distinctive geographic variants
The source sayswe conclude that, contrary to current taxonomy, Sphenodon is best described as a single species that contains distinctive and important geographic variants

Source
08

Gorniak, Rosenberg & Gans 1982

Gorniak, Rosenberg & Gans (1982). Mastication in the tuatara, Sphenodon punctatus (reptilia: Rhynchocephalia): Structure and activity of the motor system. Journal of Morphology.

The page saysa sliding jaw that makes a shearing bite
The source saysallows the animal to use its short teeth in an effective shearing bite that cuts fragments off large prey
The page saysAfter a closing, crushing bite
The source saysFood reduction consists of a closing, crushing bite followed by a propalineal sliding of the dentary row between the maxillary and palatine ones.Note: sequence is the source's own: 'a closing, crushing bite followed by a propalineal sliding'
The page saysthe lower tooth row slides forward between the upper rows in a propalineal movement
The source saysIt is followed by a propalineal anterior displacement
The page saysgiving a shearing bite that cuts fragments off large prey
The source saysallows the animal to use its short teeth in an effective shearing bite that cuts fragments off large prey

Source
09

Hitchmough 2019

Hitchmough (2019). Sphenodon punctatus. The IUCN Red List of Threatened Species 2019: e.T131735762A120191347.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: conservationStatus in stats; category read through GBIF's copy of the Red List, per source pack; iucnredlist.org refuses scripts so this is the checked category, not the assessment text

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.