Tuatara

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

Tuatara Temporal range: Early Miocene – present, 19–0  Ma PreꞒ Ꞓ O S D C P T J K Pg N [1]
Northern tuatara (Sphenodon punctatus punctatus)
Conservation status
Least Concern  (IUCN 3.1) [2] [3]
Relict (NZ TCS) [4]
Scientific 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 ^[a] is the only surviving member of its order, which was highly diverse during the Mesozoic era. ^[13] Rhynchocephalians first appeared in the fossil record during the Triassic, around 240 million years ago, ^[14] and reached worldwide distribution and peak diversity during the Jurassic, when they represented the world's dominant group of small reptiles. Rhynchocephalians declined 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) ^[10] 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] . 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 the idea that the species has survived unchanged since that time. ^{[15] [13]}

The species has between 5 and 6 billion base pairs of DNA sequence, nearly twice that of humans. ^[16]

The tuatara has been protected by law since 1895. ^{[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]

Taxonomy and evolution

Relationships of the tuatara to other living reptiles and birds, after Simões et al. 2022 ^[23]

Reptilia	Lepidosauria Squamata (lizards and snakes) Rhynchocephalia (tuatara) Archelosauria Testudines (turtles, including tortoises) Archosauria Crocodilia (crocodilians) Aves (birds)

Tuatara, along with other now-extinct members of the order Rhynchocephalia, belong to the superorder Lepidosauria, as do the order Squamata, which includes lizards and snakes. Squamates and tuatara both show caudal autotomy (loss of the tail-tip when threatened), and have transverse cloacal slits. ^[24]

Tuatara were originally classified as lizards in 1831 when the British Museum received a skull. John Edward Gray used the name Sphenodon to describe the skull; this remains the current scientific name for the genus. ^{[25] [26]} Sphenodon is derived from the Greek for "wedge" (σφήν, σφηνός/sphenos) and "tooth" (ὀδούς, ὀδόντος/odontos). ^[27] In 1842, Grey described a member of the species as Hatteria punctata, not realising that it and the skull he received in 1831 were both tuatara. ^{[28] [29]}

The genus remained misclassified as a lizard until 1867, when A.C.L.G. 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. ^[30] Since 1869, Sphenodon punctatus (or the variation Sphenodon punctatum in some earlier sources) has been used as the scientific name for the species. ^[29]

At one point, many disparate species were incorrectly referred to the Rhynchocephalia, resulting in what taxonomists call a "wastebasket taxon". ^[31] Williston in 1925 proposed the Sphenodontia to include only tuatara and their closest fossil relatives. ^[31] However, Rhynchocephalia is the older name ^[30] and in widespread use today. Many scholars use Sphenodontia as a subset of Rhynchocephalia, including almost all members of Rhynchocephalia, apart from the most primitive representatives of the group. ^[32]

The earliest rhynchocephalian, Wirtembergia , is known from the Middle Triassic of Germany, around 240 million years ago. ^[32] During the Late Triassic, rhynchocephalians greatly diversified, ^[13] going on to become the world's dominant group of small reptiles during the Jurassic period, ^[33] when the group was represented by a diversity of forms, including the aquatic pleurosaurs and the herbivorous eilenodontines. ^[33] The earliest members of Sphenodontinae, the clade which includes the tuatara, are known from the Early Jurassic of North America. The earliest representatives of this group are already very similar to the modern tuatara. ^[34] Rhynchocephalians declined during the Cretaceous period, ^[35] possibly due to competition with mammals and lizards, ^[36] with their youngest record outside of New Zealand being of Kawasphenodon , known from the Paleocene of Patagonia in South America. ^[37]

A species of sphenodontine is known from the Miocene Saint Bathans fauna from Otago in the South Island of New Zealand. Whether it is referable to Sphenodon proper is not entirely clear, but it is likely to be closely related to tuatara. The ancestors of the tuatara were likely already present in New Zealand prior to its separation from Antarctica around 82–60 million years ago. ^[36]

Cladogram of the position of the tuatara within Sphenodontia, after Simoes et al., 2022: ^[38]

Sphenodontia

† Diphydontosaurus Eusphenodontia † Planocephalosaurus † Clevosaurus Neosphenodontia † Homoeosaurus Pleurosauridae † Palaeopleurosaurus † Derasmosaurus † Pleurosaurus † Leptosaurus † Kallimodon Sapheosauridae † Piocormus † Oenosaurus † Sapheosaurus Sphenodontidae Eilenodontinae † Sphenotitan † Eilenodon † Toxolophosaurus † Priosphenodon Sphenodontinae † Navajosphenodon † Cynosphenodon † Sphenofontis † Kawasphenodon Sphenodon (tuatara)

Species

While there is currently considered to be only one living species of tuatara, two species were previously identified: Sphenodon punctatus, or northern tuatara, and the much rarer Sphenodon guntheri, or Brothers Island tuatara, which is confined to North Brother Island in the Cook Strait. ^[39] The specific name punctatus is Latin for "spotted", ^[40] and guntheri refers to German-born British herpetologist Albert Günther. ^[41] A 2009 paper re-examined the genetic bases used to distinguish the two supposed species of tuatara, and concluded they represent only geographic variants, and only one species should be recognized. ^[12] Consequently, the northern tuatara was re-classified as Sphenodon punctatus punctatus and the Brothers Island tuatara as Sphenodon punctatus guntheri. The Brothers Island tuatara has olive brown skin with yellowish patches, while the colour of the northern tuatara ranges from olive green through grey to dark pink or brick red, often mottled, and always with white spots. ^{[20] [24] [42]} In addition, the Brothers Island tuatara is considerably smaller. ^[43] However. ondividuals from Brothers Island could not be distinguished from other modern and fossil samples on the basis of jaw morphology. ^[44]

An extinct species of Sphenodon was identified in November 1885 by William Colenso, who was sent an incomplete subfossil specimen from a local coal mine. Colenso named the new species S. diversum. ^[45] Fawcett and Smith (1970) consider it a synonym to the subspecies, based on a lack of distinction. ^[46]

Description

Size comparison of male S. punctatus and human

Skeleton of the tuatara

Tuatara are the largest reptiles in New Zealand. ^[47] Adult S. punctatus males measure 61 cm (24 in) in length and females 45 cm (18 in). ^[24] Tuatara are sexually dimorphic, males being larger. ^[24] The San Diego Zoo even cites a length of up to 80 cm (31 in). ^[48] Males weigh up to 1 kg (2.2 lb), and females up to 0.5 kg (1.1 lb). ^[24] Brothers Island tuatara are slightly smaller, weighing up to 660 g (1.3 lb). ^[43]

Their lungs have a single chamber with no bronchi. ^[49]

The tuatara's greenish brown colour matches its environment, and can change over its lifetime. Tuatara shed their skin at least once per year as adults, ^[42] 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. ^[50]

Skull

Skull diagram in top down and side-on views

Unlike the vast majority of lizards, the tuatara has a complete lower temporal bar closing the lower temporal fenestra (an opening of the skull behind the eye socket), caused by the fusion of the quadrate/quadratojugal (which are fused into a single element in adult tuatara) and the jugal bones of the skull. This is similar to the condition found in primitive diapsid reptiles. However, because more primitive rhynchocephalians have an open lower temporal fenestra with an incomplete temporal bar, this is thought to be derived characteristic of the tuatara and other members of the clade Sphenodontinae, rather than a primitive trait retained from early diapsids. The complete bar is thought to stabilise the skull during biting. ^[51]

The tip of the upper jaw is chisel- or beak-like and separated from the remainder of the jaw by a notch, ^[30] this structure is formed from fused premaxillary teeth, and is also found in many other advanced rhynchocephalians. ^[52] The teeth of the tuatara, and almost all other rhynchocephalians, are described as acrodont, as they are attached to the apex of the jaw bone. This contrast with the pleurodont condition found in the vast majority of lizards, where the teeth are attached to the inward-facing surface of the jaw. The teeth of the tuatara are extensively fused to the jawbone, making the boundary between the tooth and jaw difficult to discern, and the teeth lack roots and are not replaced during the lifetime of the animal, unlike those of pleurodont lizards. ^[53] It is a common misconception that tuatara lack teeth and instead have sharp projections on the jaw bone; ^[54] histology shows that they have true teeth with enamel and dentine with pulp cavities. ^[55] As their teeth wear down, older tuatara have to switch to softer prey, such as earthworms, larvae, and slugs, and eventually have to chew their food between smooth jaw bones. ^[56]

The tuatara possesses palatal dentition (teeth growing from the bones of the roof of the mouth), which is ancestrally present in reptiles (and tetrapods generally). ^[57] While many of the original palatal teeth present in reptiles have been lost, ^[57] as in all other known rhynchocephalians, the row of teeth growing from the palatine bones in the tuatara have been enlarged, and as in other members of Sphenodontinae the palatine teeth are orientated parallel to the teeth in the maxilla; during biting the teeth of the lower jaw slot between the two upper tooth rows. ^[58] The structure of the jaw joint allows the lower jaw to slide forwards after it has closed between the two upper rows of teeth. ^[59] This mechanism allows the jaws to shear through chitin and bone. ^[24]

The brain of Sphenodon fills only half of the volume of its endocranium. ^[60] This proportion has been used by paleontologists trying to estimate the volume of dinosaur brains based on fossils. ^[60] However, the proportion of the tuatara endocranium occupied by its brain may not be a very good guide to the same proportion in Mesozoic dinosaurs since modern birds are surviving dinosaurs but have brains which occupy a much greater relative volume in the endocranium. ^[60]

• 
  Skull of the tuatara in oblique view
• 
  Skull of the tuatara in oblique view, with sclerotic rings in eye sockets
• 
  Skull of tuatara from above
• 
  Skull of tuatara from above
• 
  Tuatara skull in various views with palatine tooth row visible on underside of the skull

Sensory organs

Close-up of a tuatara's head

Eyes

The eyes can focus independently, and are specialised with three types of photoreceptive cells, all with fine structural characteristics of retinal cone cells ^[61] used for both day and night vision, and a tapetum lucidum which reflects onto the retina to enhance vision in the dark. There is also a third eyelid on each eye, the nictitating membrane. Five visual opsin genes are present, suggesting good colour vision, possibly even at low light levels. ^[62]

Parietal eye (third eye)

Like some other living vertebrates, including some lizards, the tuatara has a third eye on the top of its head called the parietal eye (also called a pineal or third eye) formed by the parapineal organ, with an accompanying opening in the skull roof called the pineal or parietal foramen, enclosed by the parietal bones. ^[63] It has its own lens, a parietal plug which resembles a cornea, ^[64] retina with rod-like structures, and degenerated nerve connection to the brain. The parietal eye is visible only 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. ^[24] While capable of detecting light, it is probably not capable of detecting movement or forming an image. ^[65] It likely serves to regulate the circadian rhythm and possibly detect seasonal changes, and help with thermoregulation. ^{[24] [63]}

Of all extant tetrapods, the parietal eye is most pronounced in the tuatara. It is part of the pineal complex, another part of which is the pineal gland, which in tuatara secretes melatonin at night. ^[24] Some salamanders have been shown to use their pineal bodies to perceive polarised light, and thus determine the position of the sun, even under cloud cover, aiding navigation. ^[66]

Hearing

Together with turtles, the tuatara has the most primitive hearing organs among the amniotes. There is no tympanum (eardrum) and no earhole, ^[54] and the middle ear cavity is filled with loose tissue, mostly adipose (fatty) tissue. The stapes comes into contact with the quadrate (which is immovable), as well as the hyoid and squamosal. The hair cells are unspecialised, innervated by both afferent and efferent nerve fibres, and respond only to low frequencies. Though the hearing organs are poorly developed and primitive with no visible external ears, they can still show a frequency response from 100 to 800  Hz, with peak sensitivity of 40  dB at 200 Hz. ^[67]

Odorant receptors

Animals that depend on the sense of smell to capture prey, escape from predators or simply interact with the environment they inhabit, usually have many odorant receptors. These receptors are expressed in the dendritic membranes of the neurons for the detection of odours. The tuatara has around 472 receptors, a number more similar to what birds have than to the large number of receptors that turtles and crocodiles may have. ^[62]

Spine and ribs

The tuatara spine is made up of hourglass-shaped amphicoelous vertebrae, concave both before and behind. ^[54] This is the usual condition of fish vertebrae and some amphibians, but is unique to tuatara within the amniotes. The vertebral bodies have a tiny hole through which a constricted remnant of the notochord passes; this was typical in early fossil reptiles, but lost in most other amniotes. ^[68]

The tuatara has gastralia, rib-like bones also called gastric or abdominal ribs, ^[69] the presumed ancestral trait of diapsids. They are found in some lizards, 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. ^[54] 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 clavicles (collar bone), would have formed a sort of exoskeleton around the body, protecting the belly and helping 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 from those of lizards, as is the case with other parts of the internal anatomy and its scales. ^[70]

Tail and back

The spiny plates on the back and tail of the tuatara resemble those of a crocodile more than a lizard, but the tuatara shares with lizards the ability to break off its tail when caught by a predator, and then regenerate it. The regrowth takes a long time and differs from that of lizards. Well illustrated reports on tail regeneration in tuatara have been published by Alibardi and Meyer-Rochow. ^{[71] [72]} The cloacal glands of tuatara have a unique organic compound named tuataric acid.

Age determination

Currently, there are two means of determining the age of tuatara. Using microscopic inspection, hematoxylinophilic rings can be identified and counted in both the phalanges and the femur. Phalangeal hematoxylinophilic rings can be used for tuatara up to ages 12–14 years, as they cease to form around this age. Femoral rings follow a similar trend, however they are useful for tuatara up to ages 25–35 years. Around that age, femoral rings cease to form. ^[73] Further research on age determination methods for tuatara is required, as tuatara have lifespans much longer than 35 years (ages up to 60 ^[9] are common, and captive tuatara have lived to over 100 years). ^{[74] [75] [76]} One possibility could be via examination of tooth wear, as tuatara have fused sets of teeth.

Physiology

A tuatara basking at the West Coast Wildlife Centre, at Franz Josef on the West Coast

Adult tuatara are 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, likely because adults are cannibalistic. Juveniles are typically active at night, but can be found active during the day. The juveniles' movement pattern is attributed to genetic hardwire of conspecifics for predator avoidance and thermal restrictions. ^[77] Tuatara thrive in temperatures much lower than those tolerated by most reptiles, and hibernate during winter. ^[78] They remain active at temperatures as low as 5 °C (41 °F), ^[79] while temperatures over 28 °C (82 °F) are generally fatal. The optimal body temperature for the tuatara is from 16 to 21 °C (61 to 70 °F), the lowest of any reptile. ^[80] The body temperature of tuatara is lower than that of other reptiles, ranging from 5.2–11.2 °C (41.4–52.2 °F) over a day, whereas most reptiles have body temperatures around 20 °C (68 °F). ^[81] The low body temperature results in a slower metabolism.

Ecology

Burrowing seabirds such as petrels, prions, and shearwaters share the tuatara's island habitat during the birds' nesting seasons. The tuatara use the birds' burrows for shelter when available, or dig their own. The seabirds' guano helps to maintain invertebrate populations on which tuatara predominantly prey, including beetles, crickets, spiders, wētās, earthworms, and snails. ^[82] Their diets also consist of frogs, lizards, and bird's eggs and chicks. ^[44] Young tuatara are also occasionally cannibalized. ^[82] The diet of the tuatara varies seasonally, and they consume mainly fairy prions and their eggs in the summer. ^[83] In total darkness no feeding attempt was observed ^[84] , and the lowest light intensity at which an attempt to snatch a beetle was observed occurred under 0.0125  lux. ^[85] The eggs and young of seabirds that are seasonally available as food for tuatara may provide beneficial fatty acids. ^[24] Tuatara of both sexes defend territories, and will threaten and eventually bite intruders. The bite can cause serious injury. ^[86] Tuatara will bite when approached, and will not let go easily. ^[87] Female tuatara rarely exhibit parental behaviour by guarding nests on islands with high rodent populations. ^[88]

Tuataras are parasitised by the tuatara tick (Archaeocroton sphenodonti), a tick that directly depends on tuataras. ^[89] These ticks tend to be more prevalent on larger males, as they have larger home ranges than smaller and female tuatara and interact with other tuatara more in territorial displays. ^[90]

Reproduction

A male tuatara named Henry, living at the Southland Museum and Art Gallery, is still reproductively active at 111 years of age. ^[74]

Tuatara juvenile (Sphenodon punctatus)

Tuatara reproduce very slowly, taking 10 to 20 years to reach sexual maturity. ^[91] Though their reproduction rate is slow, tuatara have the fastest swimming sperm by two to four times compared to all reptiles studied earlier. ^[92] Mating occurs in midsummer; females mate and lay eggs once every four years. ^[93] 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 allow the male to mount her, or retreat to her burrow. ^[94] Males do not have a penis; they have rudimentary hemipenes; meaning that intromittent organs are used to deliver sperm to the female during copulation. They reproduce by the male lifting the tail of the female and placing his vent over hers. This process is sometimes referred to as a "cloacal kiss". The sperm is then transferred into the female, much like the mating process in birds. ^[95] Along with birds, the tuatara is one of the few members of Amniota to have lost the ancestral penis. ^[96]

Tuatara eggs have a soft, parchment-like 0.2 mm thick shell that consists of calcite crystals embedded in a matrix of fibrous layers. ^[97] 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 two- to five-year intervals, the slowest in any reptile. ^[24] Survival of embryos has also been linked to having more success in moist conditions. ^[98] Wild tuatara are known to be still reproducing at about 60 years of age; "Henry", a male tuatara at Southland Museum in Invercargill, New Zealand, became a father (possibly for the first time) on 23 January 2009, at age 111, with an 80 year-old female. ^{[75] [76] [74]}

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 21 °C (70 °F) have an equal chance of being male or female. However, at 22 °C (72 °F), 80% are likely to be males, and at 20 °C (68 °F), 80% are likely to be females; at 18 °C (64 °F) all hatchlings will be females. ^[9] Some evidence indicates sex determination in tuatara is determined by both genetic and environmental factors. ^[99]

Tuatara probably have the slowest growth rates of any reptile, ^[24] continuing to grow larger for the first 35 years of their lives. ^[9] The average lifespan is about 60 years, but they can live to be well over 100 years old; ^[9] tuatara could be the reptile with the second longest lifespan after tortoises.^{[ citation needed ]} Some experts believe that captive tuatara could live as long as 200 years. ^[100] This may be related to genes that offer protection against reactive oxygen species.^{[ further explanation needed ]} The tuatara genome has 26 genes that encode selenoproteins and 4  selenocysteine-specific tRNA genes. In humans, selenoproteins have a function of antioxidation, redox regulation and synthesis of thyroid hormones. It is not fully demonstrated, but these genes may be related to the longevity of this animal or may have emerged as a result of the low levels of selenium and other trace elements in the New Zealand terrestrial systems. ^[62]

Genomic characteristics

The most abundant LINE element in the tuatara is L2 (10%). Most of them are interspersed and can remain active. The longest L2 element found is 4 kb long and 83% of the sequences had ORF2p completely intact. The CR1 element is the second most repeated (4%). Phylogenetic analysis shows that these sequences are very different from those found in other nearby species such as lizards. Finally, less than 1% are elements belonging to L1, a low percentage since these elements tend to predominate in placental mammals. ^[62] Usually, the predominant LINE elements are the CR1, contrary to what has been seen in the tuatara. This suggests that perhaps the genome repeats of sauropsids were very different compared to mammals, birds and lizards. ^[62]

The genes of the major histocompatibility complex (MHC) are known to play roles in disease resistance, mate choice, and kin recognition in various vertebrate species. Among known vertebrate genomes, MHCs are considered one of the most polymorphic. ^{[101] [102]} In the tuatara, 56 MHC genes have been identified; some of which are similar to MHCs of amphibians and mammals. Most MHCs that were annotated in the tuatara genome are highly conserved, however there is large genomic rearrangement observed in distant lepidosaur lineages. ^[62]

Many of the elements that have been analyzed are present in all amniotes, most are mammalian interspersed repeats or MIR, specifically the diversity of MIR subfamilies is the highest that has been studied so far in an amniote. 16 families of SINEs that were recently active have also been identified. ^[62]

The tuatara has 24 unique families of DNA transposons, and at least 30 subfamilies were recently active. This diversity is greater than what has been found in other amniotes and in addition, thousands of identical copies of these transposons have been analyzed, suggesting to researchers that there is recent activity. ^[62]

The genome is the second largest known to reptiles. Only the Greek tortoise genome is larger. ^[103] Around 7,500  LTRs have been identified, including 450  endogenous retroviruses (ERVs). Studies in other Sauropsida have recognized a similar number but nevertheless, in the genome of the tuatara it has been found a very old clade of retrovirus known as Spumavirus. ^[62]

More than 8,000  non-coding RNA-related elements have been identified in the tuatara genome, of which the vast majority, about 6,900, are derived from recently active transposable elements. The rest are related to ribosomal, spliceosomal and signal recognition particle RNA. ^[62]

The mitochondrial genome of the genus Sphenodon is approximately 18,000 bp in size and consists of 13 protein-coding genes, 2  ribosomal RNA and 22  transfer RNA genes. ^[62]

DNA methylation is a very common modification in animals and the distribution of CpG sites within genomes affects this methylation. Specifically, 81% of these CpG sites have been found to be methylated in the tuatara genome. Recent publications propose that this high level of methylation may be due to the amount of repeating elements that exist in the genome of this animal. This pattern is closer to what occurs in organisms such as zebrafish, about 78%, while in humans it is only 70%. ^[62]

Conservation

Tuatara are absolutely protected under New Zealand's Wildlife Act 1953. ^[104] The species is also listed under Appendix I of the Convention on International Trade in Endangered Species (CITES) meaning commercial international trade in wild sourced specimens is prohibited and all other international trade (including in parts and derivatives) is regulated by the CITES permit system. ^[105]

Tuatara sighted on the South Island mainland, in November 2024.

Distribution and threats

Tuatara were once widespread on New Zealand's main North and South Islands, where subfossil remains have been found in sand dunes, caves, and Māori middens. ^[106] Wiped out from the main islands before European settlement, they were long confined to 32 offshore islands free of mammals. ^[19] The islands are difficult to get to, ^[107] 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 rats) had recently become established on several of the islands, and tuatara were persisting, but not breeding, on these islands. ^{[108] [109]} Additionally, tuatara were much rarer on the rat-inhabited islands. ^[109] Prior to conservation work, 25% of the distinct tuatara populations had become extinct in the past century. ^[5]

The recent discovery of a tuatara hatchling on the mainland indicates that attempts to re-establish a breeding population on the New Zealand mainland have had some success. ^[110] The total population of tuatara is estimated to be between 60,000 ^[24] and 100,000. ^[111]

Climate change

Tuatara have temperature-dependent sex determination meaning that the temperature of the egg determines the sex of the animal. For tuatara, lower egg incubation temperatures lead to females while higher temperatures lead to males. Since global temperatures are increasing, climate change may be skewing the male to female ratio of tuatara. Current solutions to this potential future threat are the selective removal of adults and the incubation of eggs. ^{[112] [113]}

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 of the rats, 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 captivity, where females produced 42 eggs, which were incubated at Victoria University. The resulting offspring were subsequently held in an enclosure on the island, then released into the wild in 2006 after rats were eradicated there. ^[114]

In the Hen and Chicken Islands, Polynesian rats were eradicated on 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 have been seen there as of 2001. In the Alderman Islands, 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 in 1992 to prevent this. ^[6] 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. ^[6]

Brothers Island tuatara

Sphenodon punctatus 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 seen again and of those all but one had gained weight. In 1998, 34 juveniles from captive breeding and 20 wild-caught adults were similarly transferred to Matiu/Somes Island, a more publicly accessible location in Wellington Harbour. The captive juveniles were from induced layings from wild females. ^[6]

In late October 2007, 50 tuatara collected as eggs from North Brother Island and hatched at Victoria University were being released onto Long Island in the outer Marlborough Sounds. The animals had been cared for at Wellington Zoo for the previous five years and had been kept in secret in a specially built enclosure at the zoo, off display. ^[115]

There is another out of country population of Brothers Island tuatara that was given to the San Diego Zoological Society and is housed off-display at the San Diego Zoo facility in Balboa. ^[116] No successful reproductive efforts have been reported yet.

Northern tuatara

S. punctatus punctatus naturally occurs on 29 islands, and its population is estimated to be over 60,000 individuals. ^[24] In 1996, 32 adult northern tuatara were moved from Moutoki Island to Moutohora. The carrying capacity of Moutohora is estimated at 8,500 individuals, and the island could allow public viewing of wild tuatara. ^[6] In 2003, 60 northern tuatara were introduced to Tiritiri Matangi Island from Middle Island in the Mercury group. They are occasionally seen sunbathing by visitors to the island. ^{[117] [118]}

Tuatara at the Karori Sanctuary are given coloured markings on the head for identification.

A mainland release of S.p. punctatus occurred in 2005 in the heavily fenced and monitored Karori Sanctuary. ^[20] The second mainland release took place in October 2007, when a further 130 were transferred from Stephens Island to the Karori Sanctuary. ^[119] In early 2009, the first recorded wild-born offspring were observed. ^[120]

Captive breeding

The first successful breeding of tuatara in captivity is believed to have achieved by Sir Algernon Thomas at either his University offices or residence in Symonds Street in the late 1880s or his new home, Trewithiel, in Mount Eden in the early 1890s.^{[ citation needed ]}

Several tuatara breeding programmes are active in New Zealand. Southland Museum and Art Gallery in Invercargill was the first institution to have a tuatara breeding programme; starting in 1986 they bred S. punctatus and have focused on S. guntheri more recently. ^[121]

Hamilton Zoo, Auckland Zoo and Wellington Zoo also breed tuatara for release into the wild. At Auckland Zoo in the 1990s it was discovered that tuatara have temperature-dependent sex determination. The Victoria University of Wellington maintains a research programme into the captive breeding of tuatara, and the Pūkaha / Mount Bruce National Wildlife Centre keeps a pair and a juvenile.^{[ citation needed ]}

The WildNZ Trust has a tuatara breeding enclosure at Ruawai. One notable captive breeding success story took place in January 2009, when all 11 eggs belonging to 110 year-old tuatara Henry and 80 year-old tuatara Mildred hatched. This story is especially remarkable as Henry required surgery to remove a cancerous tumour in order to successfully breed. ^[100]

In January 2016, Chester Zoo, England, announced that they succeeded in breeding the tuatara in captivity for the first time outside its homeland. ^[122]

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 god of death and disaster, and Māori women are forbidden to eat them. ^[123] Tuatara also indicate tapu (the borders of what is sacred and restricted), ^[124] beyond which there is mana, meaning there could be serious consequences if that boundary is crossed. ^[124] Māori women would sometimes tattoo images of lizards, some of which may represent tuatara, near their genitals. ^[124] Today, tuatara are regarded as a taonga (special treasure) along with being viewed as the kaitiaki (guardian) of knowledge. ^{[125] [126]}

The tuatara was featured on one side of the New Zealand five-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. It has now been digitised by the New Zealand Electronic Text Centre, also at Victoria. ^[127]

In popular culture

• A tuatara named "Tua" is prominently featured in the 2017 novel Turtles All the Way Down by John Green. ^[128]
• There is a brand of New Zealand craft beer named after the Tuatara which particularly references the third eye in its advertising. ^[129]
• In the season one finale of Abbott Elementary ^[130] an old tuatara named Duster is used to represent themes of ageing and transition.
• In the 2023 animated movie Leo , the main character is a tuatara named Leo.

Notes

1. A second species, the Brothers Island tuatara S. guntheri(Buller, 1877), was recognised in 1989, ^[10] but since 2009 it has been reclassified as a subspecies, S.p. guntheri. ^{[11] [12]}

See also

• Reptilesportal
• Evolutionary biologyportal
• New Zealandportal

References

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. Cree, A., Daugherty, C.H., Hay, J.M. (1 September 1990). "Neglected taxonomy and continuing extinctions of tuatara (Sphenodon)". Nature. 347 (6289): 177–179. Bibcode:1990Natur.347..177D. doi:10.1038/347177a0. S2CID   4342765.
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. "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.
10. "Reptiles:Tuatara". Animal Bytes. Zoological Society of San Diego. 2007. Archived from the original on 30 November 2012. Retrieved 1 June 2007.
11. Cree, A. (2014). Tuatara: Biology and conservation of a venerable survivor. Canterbury University Press. ISBN   978-1-927145-44-9.
12. 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.
13. 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 .
14. 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.
15. 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.
16. Elder, V. (26 November 2012). "Tuatara genome mapping". Otago Daily Times. Retrieved 10 June 2018.
17. Newman 1987
18. 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.
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. "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.
23. Simões TR, Kammerer CF, Caldwell MW, Pierce SE (19 August 2022). "Successive climate crises in the deep past drove the early evolution and radiation of reptiles". Science Advances. 8 (33): eabq1898. Bibcode:2022SciA....8.1898S. doi:10.1126/sciadv.abq1898. ISSN   2375-2548. PMC   9390993 . PMID   35984885.
24. Cree, A. (2002). "Tuatara". In Halliday, T., Alder, K. (eds.). The New Encyclopedia of Reptiles and Amphibians. Oxford, UK: Oxford University Press. pp. 210–211. ISBN   0-19-852507-9.
25. Gray, John Edward, The zoological miscellany : to be continued occasionally, London: Published by Treuttel, Wurtz and Co., G.B. Sowerby, W. Wood, pp. 13–14, doi:10.5962/BHL.TITLE.113722, OCLC   2319292, OL   25908786M, Wikidata   Q51389982
26. Lutz 2005 , p. 42
27. "Sphenodon". Dictionary.com Unabridged (v 1.1 ed.). Random House. Retrieved 8 January 2007.
28. Gray, John Edward, The zoological miscellany : to be continued occasionally, London: Published by Treuttel, Wurtz and Co., G.B. Sowerby, W. Wood, p. 72, doi:10.5962/BHL.TITLE.113722, OCLC   2319292, OL   25908786M, Wikidata   Q51389982
29. Gray, J. E. (February 1869). "Sphenodon, Hatteria, and Rhynchocephalus". Annals and Magazine of Natural History. 3 (14): 167–168. doi:10.1080/00222936908695904. ISSN   0374-5481. Wikidata   Q56103814.
30. Günther, A. (1867). "Contribution to the anatomy of Hatteria (Rhynchocephalus, Owen)". Philosophical Transactions of the Royal Society. 157: 595–629. Bibcode:1867RSPT..157..595G. doi: 10.1098/rstl.1867.0019 . JSTOR   108983.
31. Fraser, N., Sues, H.D., eds. (1994). "Phylogeny" in the Shadow of the Dinosaurs: Early Mesozoic Tetrapods. Cambridge University Press. ISBN   978-0-521-45242-7.
32. Sues HD, Schoch RR (7 November 2023). "The oldest known rhynchocephalian reptile from the Middle Triassic (Ladinian) of Germany and its phylogenetic position among Lepidosauromorpha". The Anatomical Record. 307 (4): 776–790. doi:10.1002/ar.25339. ISSN   1932-8486. PMID   37937325.
33. Brownstein CD, Meyer DL, Fabbri M, Bhullar BA, Gauthier JA (29 November 2022). "Evolutionary origins of the prolonged extant squamate radiation". Nature Communications. 13 (1): 7087. Bibcode:2022NatCo..13.7087B. doi:10.1038/s41467-022-34217-5. ISSN   2041-1723. PMC   9708687 . PMID   36446761.
34. Simões TR, Kinney-Broderick G, Pierce SE (3 March 2022). "An exceptionally preserved Sphenodon-like sphenodontian reveals deep time conservation of the tuatara skeleton and ontogeny". Communications Biology. 5 (1): 195. doi: 10.1038/s42003-022-03144-y . ISSN   2399-3642. PMC   8894340 . PMID   35241764.
35. Cleary TJ, Benson RB, Evans SE, Barrett PM (March 2018). "Lepidosaurian diversity in the Mesozoic–Palaeogene: the potential roles of sampling biases and environmental drivers". Royal Society Open Science. 5 (3): 171830. Bibcode:2018RSOS....571830C. doi:10.1098/rsos.171830. ISSN   2054-5703. PMC   5882712 . PMID   29657788.
36. Jones ME, Tennyson AJ, Worthy JP, Evans SE, Worthy TH (April 2009). "A sphenodontine (Rhynchocephalia) from the Miocene of New Zealand and palaeobiogeography of the tuatara (Sphenodon)". Proceedings. Biological Sciences. 276 (1660): 1385–90. doi:10.1098/rspb.2008.1785. PMC   2660973 . PMID   19203920.
37. Apesteguía S, Gómez RO, Rougier GW (October 2014). "The youngest South American rhynchocephalian, a survivor of the K/Pg extinction". Proceedings of the Royal Society B: Biological Sciences. 281 (1792): 20140811. doi:10.1098/rspb.2014.0811. PMC   4150314 . PMID   25143041.
38. Simões TR, Kinney-Broderick G, Pierce SE (3 March 2022). "An exceptionally preserved Sphenodon-like sphenodontian reveals deep time conservation of the tuatara skeleton and ontogeny". Communications Biology. 5 (1): 195. doi: 10.1038/s42003-022-03144-y . ISSN   2399-3642. PMC   8894340 . PMID   35241764.
39. "Tuatara – Sphenodon punctatus". Science and Nature: Animals. BBC (bbc.co.uk). Archived from the original on 28 August 2005. Retrieved 28 February 2006.
40. Stearn, W.T. (1 April 2004). Botanical Latin. Portland, OR: Timber Press. p. 476. ISBN   978-0-88192-627-9 – via Google Books.
41. Beolens, Bo, Watkins, Michael, Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore, Maryland: Johns Hopkins University Press. ISBN   978-1-4214-0135-5. xiii + 296 pp. (Sphenodon guntheri, p. 110).
42. Lutz 2005 , p. 16
43. Gill, B., Whitaker, T. (1996). New Zealand Frogs and Reptiles. David Bateman Publishing. pp. 22–24. ISBN   1-86953-264-3.
44. Vaux, F., Morgan-Richards, M., Daly, E.E., Trewick, S.A. (2019). "Tuatara and a new morphometric dataset for Rhynchocephalia: Comments on Herrera-Flores et al.". Palaeontology. 62 (2): 321–334. Bibcode:2019Palgy..62..321V. doi:10.1111/pala.12402. S2CID   134902015.
45. Colenso, W. (1885). "Notes on the bones of a species of Sphenodon, (S. diversum, Col.,) apparently distinct from the species already known" (PDF). Transactions and Proceedings of the Royal Society of New Zealand. 18: 118–128.
46. Fawcett JD, Smith HM (1970). "An Overlooked Synonym of Sphenodon punctatus, the New Zealand Tuatara". Journal of Herpetology. 4 (1–2): 89–91. doi:10.2307/1562712. JSTOR   1562712.
47. "Tuatara". www.doc.govt.nz. Retrieved 12 December 2022.
48. "Tuatara". Animal Bytes. San Diego Zoo. Archived from the original on 30 November 2012. Retrieved 19 April 2008.
49. Jacobson, E.R. (11 April 2007). Infectious Diseases and Pathology of Reptiles. CRC Press. ISBN   978-1-4200-0403-8.
50. "Tuataras". Animal Corner. Archived from the original on 17 March 2015. Retrieved 31 December 2007.
51. Simões TR, Kinney-Broderick G, Pierce SE (3 March 2022). "An exceptionally preserved Sphenodon-like sphenodontian reveals deep time conservation of the tuatara skeleton and ontogeny". Communications Biology. 5 (1): 195. doi:10.1038/s42003-022-03144-y. ISSN   2399-3642. PMC   8894340 . PMID   35241764.
52. Herrera-Flores JA, Stubbs TL, Elsler A, Benton MJ (July 2018). "Taxonomic reassessment of Clevosaurus latidens Fraser, 1993 (Lepidosauria, Rhynchocephalia) and rhynchocephalian phylogeny based on parsimony and Bayesian inference". Journal of Paleontology. 92 (4): 734–742. Bibcode:2018JPal...92..734H. doi: 10.1017/jpa.2017.136 . hdl: 1983/59126b60-16d8-46d2-b657-954693a39d4e . ISSN   0022-3360.
53. Jenkins KM, Jones ME, Zikmund T, Boyde A, Daza JD (September 2017). "A Review of Tooth Implantation Among Rhynchocephalians (Lepidosauria)". Journal of Herpetology. 51 (3): 300–306. doi:10.1670/16-146. ISSN   0022-1511. S2CID   90519352.
54. Lutz 2005 , p. 27
55. Kieser JA, Tkatchenko T, Dean MC, Jones ME, Duncan W, Nelson NJ (2009). "Microstructure of dental hard tissues and bone in the Tuatara dentary, Sphenodon punctatus (Diapsida: Lepidosauria: Rhynchocephalia)". Frontiers of Oral Biology. 13: 80–85. doi:10.1159/000242396. ISBN   978-3-8055-9229-1. PMID   19828975.
56. Mlot, C. (8 November 1997). "Return of the Tuatara: A relic from the age of dinosaurs gets a human assist" (PDF). Science News. Retrieved 24 May 2007.
57. Matsumoto R, Evans SE (January 2017). "The palatal dentition of tetrapods and its functional significance". Journal of Anatomy . 230 (1): 47–65. doi:10.1111/joa.12534. PMC   5192890 . PMID   27542892.
58. Jones, M.E. (August 2008). "Skull shape and feeding strategy in Sphenodon and other Rhynchocephalia (Diapsida: Lepidosauria)". Journal of Morphology. 269 (8): 945–66. doi: 10.1002/jmor.10634 . PMID   18512698. S2CID   16357353.
59. Jones ME, O'higgins P, Fagan MJ, Evans SE, Curtis N (July 2012). "Shearing mechanics and the influence of a flexible symphysis during oral food processing in Sphenodon (Lepidosauria: Rhynchocephalia)". The Anatomical Record. 295 (7): 1075–91. doi: 10.1002/ar.22487 . PMID   22644955. S2CID   45065504.
60. Larsson HC (2001). "Endocranial anatomy of Carcharodontosaurus saharicus (Theropoda: Allosauroidea) and its implications for theropod brain evolution". In Tanke DH, Carpenter K, Skrepnick MW (eds.). Mesozoic Vertebrate Life. Bloomington & Indianapolis: Indiana University Press. pp. 19–33. ISBN   0-253-33907-3.
61. Meyer-Rochow VB, Wohlfahrt S, Ahnelt PK (2005). "Photoreceptor cell types in the retina of the tuatara (Sphenodon punctatus) have cone characteristics". Micron. 36 (5): 423–428. doi:10.1016/j.micron.2005.03.009. PMID   15896966.
62. Gemmell NJ, Rutherford K, Prost S, Tollis M, Winter D, Macey JR, et al. (August 2020). "The tuatara genome reveals ancient features of amniote evolution". Nature. 584 (7821): 403–409. doi: 10.1038/s41586-020-2561-9 . PMC   7116210 . PMID   32760000.
63. Smith KT, Bhullar BA, Köhler G, Habersetzer J (April 2018). "The Only Known Jawed Vertebrate with Four Eyes and the Bauplan of the Pineal Complex". Current Biology. 28 (7): 1101–1107.e2. Bibcode:2018CBio...28E1101S. doi: 10.1016/j.cub.2018.02.021 . ISSN   0960-9822. PMID   29614279.
64. Schwab, I.R., O'Connor, G.R. (March 2005). "The lonely eye". The British Journal of Ophthalmology. 89 (3): 256. doi:10.1136/bjo.2004.059105. PMC   1772576 . PMID   15751188.
65. Jones ME, Cree A (December 2012). "Tuatara". Current Biology. 22 (23): R986–R987. doi:10.1016/j.cub.2012.10.049.
66. Halliday, T.R. (2002). "Salamanders and newts: Finding breeding ponds". In Halliday, T., Adler, K. (eds.). The New Encyclopedia of Reptiles and Amphibians. Oxford, UK: Oxford University Press. p. 52. ISBN   0-19-852507-9.
67. Kaplan, Melissa (6 September 2003). "Reptile Hearing". Melissa Kaplan's herp care collection. Retrieved 24 July 2006.
68. Romer, A.S., Parsons, T.S. (1977). The Vertebrate Body (Fifth ed.). Philadelphia, PA: W.B. Saunders. p. 624. ISBN   978-0-7216-7668-5.
69. "Tuatara". Berlin Zoo Aquarium. Archived from the original on 14 August 2007. Retrieved 11 September 2007.
70. Wattie, T. "Tuatara Reptile, New Zealand". www.kiwizone.org. Archived from the original on 14 November 2007. Retrieved 31 December 2007.
71. Alibardi, L., Meyer-Rochow, V.B. (1990). "Ultrastructural survey of the spinal cord of young tuatara (Sphenodon punctatus) with emphasis on the glia". New Zealand Journal of Zoology. 17: 73–85. doi:10.1080/03014223.1990.10422586.
72. Alibardi, L., Meyer-Rochow, V.B. (1990). "Fine structure of regenerating caudal spinal cord in adult tuatara (Sphenodon punctatus)". Journal für Hirnforschung. 31 (5): 613–21. PMID   1707076.
73. Castanet, J., Newman, D.G., Girons, H.S. (1988). "Skeletochronological data on the growth, age, and population structure of the tuatara, Sphenodon punctatus, on Stephens and Lady Alice Islands, New Zealand". Herpetologica. 44 (1): 25–37. JSTOR   3892195.
74. "111 year-old reptile becomes a dad after tumor surgery". Discover Magazine . 26 January 2009. Archived from the original on 15 October 2012. Retrieved 31 January 2013.
75. "Tuatara becomes a father for the first time, aged 111". The New Zealand Herald . 26 January 2009. Retrieved 28 June 2009.
76. "Reptile becomes a father, at 111". BBC News . 26 January 2009. Retrieved 28 June 2009.
77. Terezow MG, Nelson NJ, Markwell TJ (January 2008). "Circadian emergence and movement of captive juvenile tuatara (Sphenodonspp.)". New Zealand Journal of Zoology. 35 (3): 205–216. doi: 10.1080/03014220809510116 . ISSN   0301-4223. S2CID   83781111.
78. "Tuatara: Facts". Southland Museum. 18 January 2006. Archived from the original on 9 June 2007. Retrieved 2 June 2007.
79. Schofield, E. (24 March 2009). "New arrivals thrill staff at sanctuary". Otago Daily Times. Otago, NZ. Retrieved 23 March 2009.
80. Musico, B. (1999). "Sphenodon punctatus". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 22 April 2006.
81. Thompson, M.B., Daugherty, C.H. (1998). "Metabolism of tuatara, Sphenodon punctatus". Comparative Biochemistry and Physiology A. 119 (2): 519–522. doi:10.1016/S1095-6433(97)00459-5.
82. "Sphenodon punctatus (Tuatara)". Animal Diversity Web .
83. Fraser J (1993). Diets of wild tuatara (Sphenodon punctatus) on Stephens Island (Thesis thesis). University of Otago.
84. Meyer-Rochow, V.B. (1988). "Behaviour of young tuatara (Sphenodon punctatus) in total darkness". Tuatara. 30: 36–38.
85. Meyer-Rochow VB, Teh KL (July 1991). "Visual Predation by Tuatara (Sphenodon Punctatus) on the Beach Beetle (Chaerodes Trachyscelides) as a Selective force in the Production of Distinct Colour Morphs". Tuatara: Journal of the Biological Society. 31 (1): 1–8 – via Victoria University of Wellington.
86. Daugherty, C., Keall, S. "Tuatara: Life History". Te Ara – the Encyclopedia of New Zealand.
87. Lutz 2005 , p. 24
88. Refsnider JM, Keall SN, Daugherty CH, Nelson NJ (2009). "Does Nest-Guarding in Female Tuatara (Sphenodon punctatus) Reduce Nest Destruction by Conspecific Females?". Journal of Herpetology. 43 (2): 294–299. doi:10.1670/08-120R1.1.
89. Godfrey SS, Bull CM, Nelson NJ (2008). "Seasonal and spatial dynamics of ectoparasite infestation of a threatened reptile, the tuatara (Sphenodon punctatus)". Medical and Veterinary Entomology. 22 (4): 374–385. doi:10.1111/j.1365-2915.2008.00751.x. PMID   19120965. S2CID   20718129.
90. Godfrey S, Moore J, Nelson N, Bull M (2010). "Social network structure and parasite infection patterns in a territorial reptile, the tuatara (Sphenodon punctatus)". International Journal for Parasitology. 40 (13): 1575–1585. doi:10.1016/j.ijpara.2010.06.002. PMID   20637210.
91. Angier, N. (22 November 2010). "Reptile's pet-store looks belie its Triassic appeal". The New York Times . Retrieved 21 December 2010.
92. Ormsby DK, Moore J, Nelson NJ, Lamar SK, Keall SN (3 August 2021). "Tuatara are ancient, slow and endangered. But their super speedy sperm could boost conservation efforts". The Conversation. Retrieved 12 December 2022.
93. Cree, A., Cockrem, J.F., Guillette, L.J. (1992). "Reproductive cycles of male and female tuatara (Sphenodon punctatus) on Stephens Island, New Zealand". Journal of Zoology. 226 (2): 199–217. doi:10.1111/j.1469-7998.1992.tb03834.x.
94. Gans, C., Gillingham, J.C., Clark, D.L. (1984). "Courtship, mating and male combat in Tuatara, Sphenodon punctatus". Journal of Herpetology. 18 (2): 194–197. doi:10.2307/1563749. JSTOR   1563749.
95. Lutz 2005 , p. 19
96. Brennan, P.L. (January 2016). "Evolution: One penis after all". Current Biology. 26 (1): R29-31. Bibcode:2016CBio...26..R29B. doi: 10.1016/j.cub.2015.11.024 . PMID   26766229.
97. Packard, M.J., Hirsch, K.F., Meyer-Rochow, V.B. (November 1982). "Structure of the shell from eggs of the tuatara, Sphenodon punctatus". Journal of Morphology. 174 (2): 197–205. doi:10.1002/jmor.1051740208. PMID   30096972. S2CID   51957289.
98. Thompson MB, Packard GC, Packard MJ, Rose B (February 1996). "Analysis of the nest environment of tuatara Sphenodon punctatus". Journal of Zoology. 238 (2): 239–251. doi:10.1111/j.1469-7998.1996.tb05392.x. ISSN   0952-8369.
99. Cree, A., Thompson, M.B., Daugherty, C.H. (1995). "Tuatara sex determination". Nature. 375 (6532): 543. Bibcode:1995Natur.375..543C. doi: 10.1038/375543a0 . S2CID   4339729.
100. "110 year-old 'living fossil' becomes a dad". CNN. 30 January 2009. Retrieved 28 June 2009.
101. Sommer, S. (October 2005). "The importance of immune gene variability (MHC) in evolutionary ecology and conservation". Frontiers in Zoology. 2 (1): 16. doi: 10.1186/1742-9994-2-16 . PMC   1282567 . PMID   16242022.
102. Rymešová D, Králová T, Promerová M, Bryja J, Tomášek O, Svobodová J, et al. (16 February 2017). "Mate choice for major histocompatibility complex complementarity in a strictly monogamous bird, the grey partridge (Perdix perdix)". Frontiers in Zoology. 14: 9. doi: 10.1186/s12983-017-0194-0 . PMC   5312559 . PMID   28239400.
103. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?
104. "Wildlife Act 1953". New Zealand Legislation. Parliamentary Counsel Office. Retrieved 18 January 2022.
105. "Appendices". CITES (cites.org). Convention on International Trade in Endangered Species . Retrieved 14 January 2022.
106. Towns, D.R., Daugherty, C.H., Cree, A. (2001). "Raising the prospects for a forgotten fauna: A review of 10 years of conservation effort for New Zealand reptiles". Biological Conservation. 99 (1): 3–16. Bibcode:2001BCons..99....3T. doi:10.1016/s0006-3207(00)00184-1. Archived from the original on 24 April 2014. Retrieved 11 March 2012.
107. Lutz 2005 , pp. 59–60
108. 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. JSTOR   24061518.
109. Cree, A., Daugherty, C.H., 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 (2): 373–383. Bibcode:1995ConBi...9..373C. doi:10.1046/j.1523-1739.1995.9020373.x.
110. "Rare reptile hatchling found in New Zealand". The Guardian . 20 March 2009.
111. Daugherty, C., Keall, S. "Tuatara islands". Te Ara – the Encyclopedia of New Zealand.
112. "A Threat to New Zealand's Tuatara Heats Up". American Scientist. 6 February 2017. Retrieved 12 December 2022.
113. Hoare JM, Pledger S, Keall SN, Nelson NJ, Mitchell NJ, Daugherty CH (November 2006). "Conservation implications of a long-term decline in body condition of the Brothers Island tuatara ( Sphenodon guntheri )". Animal Conservation. 9 (4): 456–462. Bibcode:2006AnCon...9..456H. doi:10.1111/j.1469-1795.2006.00061.x. S2CID   86412390.
114. Fauna on Little Barrier Island. Department of Conservation (Report). Government of New Zealand. Archived from the original on 29 March 2014. Retrieved 3 February 2013.
115. "Rare tuatara raised at Wellington Zoo" (Press release). Wellington Zoo. 29 October 2007. Retrieved 19 April 2008.
116. "Tuatara". At the Zoo. Reptiles. San Diego Zoo Wildlife Alliance. Retrieved 11 May 2014.
117. "Translocated reptiles" (PDF). Tiritiri Matangi: An education resource for schools. Department of Conservation, Government of New Zealand.
118. "Tiritiri Matangi Island field trip". Tiritiri Matangi – An education resource for schools. Department of Conservation, Government of New Zealand. November 2007. Archived from the original on 29 March 2014.
119. "130 tuatara find sanctuary". The Dominion Post . Wellington, NZ. 20 October 2007. Archived from the original on 10 December 2008. Retrieved 19 April 2008.
120. Easton, P. (20 March 2009). "Life will be wild for new boy". The Dominion Post . Wellington, NZ. Archived from the original on 14 June 2009. Retrieved 20 March 2009.
121. Lutz RL (2006). Tuatara: a living fossil. Salem, OR: Dimi Press. p. 53. Retrieved 22 November 2022.
122. Connor, S. (31 January 2016). "Tuatara: Lizard-like reptile takes 38 years to lay an egg in Chester Zoo". The Independent . Retrieved 31 January 2016.
123. Williams, D. (2001). "Chapter 6: Traditional Kaitiakitanga Rights and Responsibilities" (PDF). Wai 262 Report: Matauranga Maori and Taonga. Waitangi Tribunal. Archived from the original (PDF) on 28 June 2007. Retrieved 2 June 2007.
124. Ramstad KM, Nelson NJ, Paine G, Beech D, Paul A, Paul P, et al. (April 2007). "Species and cultural conservation in New Zealand: maori traditional ecological knowledge of tuatara". Conservation Biology. 21 (2): 455–64. Bibcode:2007ConBi..21..455R. doi:10.1111/j.1523-1739.2006.00620.x. PMID   17391195. S2CID   39213356.
125. Lutz 2005 , p. 64
126. Taonga NZ. "Life history". teara.govt.nz. Retrieved 12 December 2022.
127. "Tuatara: Journal of the Biological Society". Wellington, NZ: New Zealand Electronic Text Centre. Retrieved 19 April 2008.
128. Ganz, J. (23 June 2017). "Everything we know about John Green's new book". EW.com. Retrieved 15 October 2017.
129. "About – The Third Eye". Tuatarabrewing.co.nz. Tuatara Breweries. Retrieved 10 June 2018.
130. "s01e13 – Zoo Balloon – Abbott Elementary Transcripts – TvT" . Retrieved 2 October 2022.^{[ permanent dead link ‍]}

Further reading

• Blanchard B, et al. (Tuatara Recovery Group) (June 2002). Jasperse J, Rolfe J (eds.). Tuatara captive management plan and husbandry manual (PDF). Threatened Species Occasional Publication. Vol. 21. Wellington, New Zealand: Department of Conservation. Retrieved 26 November 2007.
• Bry L. "Evolution of a third eye in some animals?". MadSci Network. Retrieved 9 August 2007.
• Daugherty C, Keall S. "Tuatara". Te Ara – the Encyclopedia of New Zealand. Archived from the original on 15 October 2008.
• Daugherty CH, Cree A (April 1990). "Tuatara: a survivor from the dinosaur age". New Zealand Geographic. 6: 66–86.
• Gill V (30 May 2012). "Tuatara reptile slices food with 'steak-knife teeth". BBC Nature. Archived from the original on 26 August 2017. Retrieved 8 January 2014.
• Lutz D (2005). Tuatara: A Living Fossil. Salem, Oregon: Dimi Press. ISBN   978-0-931625-43-5.
• Maisano J. "Sphenodon punctatus (tuatara) – 3D visualisations from X-ray CT scans". Digimorph. University of Texas at Austin. Retrieved 8 May 2006.
• Marris J. "Images and movies of the Brothers Island tuatara (Sphenodon guntheri)". ARKive: Images of Life on Earth. Archived from the original on 26 June 2007. Retrieved 3 June 2007.
• McKintyre M (1997). Conservation of the Tuatara. Victoria University Press. ISBN   978-0-86473-303-0.
• Mulligan J (18 August 2017). "Tuatara". Critter of the Week. RNZ.
• Newman DG (1987). Tuatara. Endangered New Zealand Wildlife Series. Dunedin, New Zealand: John McIndoe. ISBN   978-0-86868-098-9.
• Parkinson B (2000). The Tuatara. Reed Children's Books. ISBN   978-1-86948-831-4.
• Schwab IR, O'Connor GR (March 2005). "The lonely eye". The British Journal of Ophthalmology. 89 (3): 256. doi:10.1136/bjo.2004.059105. PMC   1772576 . PMID   15751188.

External links

• Media related to Sphenodon at Wikimedia Commons
• Data related to Sphenodon at Wikispecies
• "Specimens of Tuatara". Te Papa Tongarewa: The collection of the Museum of New Zealand.