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| For the experimental music band, see Tuatara (band).The tuatara is an amniote of the family Sphenodontidae, endemic to New Zealand.Tuatara resemble lizards, but are equally related to lizards and snakes, 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 diapsids (the group that additionally includes birds and crocodiles).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.Tuatara, like many of New Zealand's native animals, are threatened by habitat loss and the introduced Polynesian Rat (Rattus exulans).Taxonomy and evolution
2 Description
2.Distribution and threats
4.Brothers Island tuatara
4.Taxonomy and evolution
Tuatara, and their sister group Squamata (which includes lizards, snakes and amphisbaenians), belong to the superorder Lepidosauria, the only surviving taxon within Lepidosauromorpha.The origin of the tuatara probably lies close to the split between the Lepidosauromorpha and the Archosauromorpha.Though tuatara resemble lizards, the similarity is mostly superficial, since the family has several characteristics unique among reptiles.The typical lizard shape is very common for the early amniotes; the oldest known fossil of a reptile, the Hylonomus, resembles a modern lizard.Birds
"Lizards" are polyphyletic.Tuatara were originally classified as lizards in 1831 when the British Museum received a skull.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.Now, most authors prefer to use the more exclusive order name of Sphenodontia for the tuatara and its closest living relatives.During the years since the description of the Rhynchocephalia, many disparately related species have been added to this order.In 1925, Williston proposed the Sphenodontia to include only tuatara and their closest fossil relatives.Tuatara have been referred to as living fossils.This means that they have remained mostly unchanged throughout their entire history, which is approximately 220 million years.There was even a successful group of aquatic sphenodontians known as 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 of tuatara: Sphenodon punctatus and the much rarer Sphenodon guntheri, or Brothers Island tuatara, which is confined to North Brother Island in Cook Strait.The Brother's Island tuatara (S.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.Size comparison of tuatara 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.Brother's Island tuatara are slightly smaller, weighing up to 660g.Tuatara sexes differ in more than size.The spiny crest on a tuatara's back, made of triangular soft folds of skin, is bigger in males than in females, and can be stiffened for display.The male abdomen is narrower than the female's.Skull of a tuatara, showing the complete temporal arches.Skull
In the course of evolution, the skull has been modified in most diapsids from the original version evident in the fossil record.However, in the tuatara, all the original features are preserved: it has two openings (temporal fenestra) on each side of the skull, with complete arches.In addition, in the tuatara, the upper jaw is firmly attached to the skull.There is a single row of teeth in the lower jaw and a double row in the upper jaw, with the bottom row fitting perfectly between the two upper rows when the mouth is closed.This is a tooth arrangement not seen in any other reptiles; although most snakes also have a double row of teeth in their upper jaw, their arrangement and function is different from the tuatara's.The tuatara's teeth are not replaced, since they are not separate structures like real teeth, but sharp projections of the jaw bone.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.Sensory organs
In tuatara, both eyes can focus independently, and are specialized with a "duplex retina" that contains two types of visual cells for vision by both day and night, and a tapetum lucidum which reflects on to the retina to enhance vision at night.The tuatara has a third eye on the top of its head called the parietal 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.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.Together with turtles, the tuatara has the most primitive hearing organs among the amniotes.The stapes comes into contact with the quadrate (which is immovable) as well as the hyoid and squamosal.This is the usual condition of fish vertebrae and some amphibians, but is unique to tuatara within the amniotes.They are found in some lizards (in lizards they are mostly made of cartilage), crocodiles and the tuatara, and are not attached to the spine or thoracic ribs.The real ribs are small projections, with small, hooked bones, called uncinate processes, found on the rear of each rib.This feature is also present in birds.The tuatara is the only living tetrapod with well developed gastralia and uncinate processes.These anatomical details most likely evolved from structures involved in locomotion even before the vertebrates migrated onto land.Behaviour
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.Tuatara thrive in temperatures much lower than those tolerated by most reptiles, and hibernate during winter.The body temperature of tuatara is lower than that of other reptiles ranging from 5.Burrowing seabirds such as petrels, prions and shearwaters 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 beetles, crickets and spiders.Their diet also consists of frogs, lizards and bird's eggs and chicks.The eggs and young of seabirds that are seasonally available as food for tuatara may provide beneficial fatty acids.Tuatara will bite when approached, and do not let go easily.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.Tuatara reproduce very slowly, taking ten years to reach sexual maturity.Mating occurs in midsummer; females mate and lay eggs once every four years.During courtship, a male makes his skin darker, raises his crests and parades toward the female.Males do not have a penis; they reproduce by the male lifting the tail of the female and placing his vent over hers.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.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.There is some evidence that sex determination in tuatara is determined by both genetic and environmental factors.Current distribution of tuatara (in black).Circles represent the North Island tuatara, squares the Brothers Island tuatara.Symbols may represent up to seven islands.However, kiore (Polynesian rats) had recently established on several of the islands, and tuatara were persisting, but not breeding, on these islands.Brothers Island tuatara
Sphenodon guntheri is present naturally on one small island with a population of approximately 400.Brothers Island tuatara were moved to Titi Island in Cook Strait, and their establishment monitored.Matiu Island, a more publicly accessible location.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 Straight.The carrying capacity of Moutohora is estimated at 8500 individuals, and the island could allow public viewing of wild tuatara.Eradication of rats
In 1990 and 1991, tuatara were removed from Stanley, Red Mercury and Cuvier Islands, and maintained in captivity to allow Pacific 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.Pacific rats were, however, 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.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.Tuatara at the Karori Wildlife Sanctuary are given coloured markings on the head for identification.Captive breeding
There are several Tuatara breeding programmes within New Zealand.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 Pukaha Mount Bruce Wildlife Centre keeps a pair and 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).Today, tuatara are regarded as a taonga (special treasure).The tuatara was featured on one side of the 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.New York, New York: DK Publishing, Inc.Threatened Species Recovery Plan Series No.Threatened Species Unit, Department of Conservation, Government of New Zealand.Threatened Species Unit, Department of Conservation, Government of New Zealand.Tuatara Factsheet (Sphenodon punctatus).Kiwi Conservation Club: Fact Sheets.Royal Forest and Bird Protection Society of New Zealand Inc.The new encyclopedia of reptiles and amphibians, Oxford University Press, Oxford, pp.Lepidosauromorpha: Lizards, snakes, Sphenodon, and their extinct relatives..Tree of Life Web Project (1995).Tuatara, Relics of a Lost Age.Science and Nature: Animals.Portland, Oregon: Timber Press Inc, p.New Zealand Frogs and reptiles.David Bateman publishing, pp.Tuataras at Animal Corner."Turtles as diapsid reptiles.""Complete mitochondrial genome suggests diapsid affinities of turtles."Return of the Tuatara:A relic from the age of dinosaurs gets a human assist.The new encyclopedia of reptiles and amphibians, Oxford University Press, Oxford, p.Melissa Kaplan's Herp Care Collection.Tuatara Reptile, New Zealand.University of Michigan Museum of Zoology."Metabolism of tuatara, Sphenodon punctatus"."Reproductive cycles of male and female tuatara (Sphenodon punctatus) on Stephens Island, New Zealand"."Courtship, mating and male combat in Tuatara, Sphenodon punctatus".Neglected taxonomy and continuing extinctions of tuatara (Sphenodon).Threatened Species Recovery Plan 47.Biodiversity Recovery Unit, Department of Conservation, Government of New Zealand.New Zealand Herald: Tuatara Release.The tuatara, Sphenodon punctatus Gray, on islands with and without populations of the Polynesian rat, Rattus exulans (Peale)."Rare tuatara raised at Wellington Zoo", 29 October 2007.The Dominion Post, 20 October 2007.Wai 262 Report: Matauranga Maori and Taonga.Daugherty (2007) Species and Cultural Conservation in New Zealand: Maori Traditional Ecological Knowledge of Tuatara.Conservation of the Tuatara.Tuatara captive management plan and husbandry manual (PDF).Department of Conservation, Wellington, New Zealand.Brothers Island tuatara (Sphenodon guntheri).This page was last modified 20:33, 2 January 2008.All text is available under the terms of the GNU Free Documentation License.See Copyrights for details.For the experimental music band, see Tuatara (band).The tuatara is an amniote of the family Sphenodontidae, endemic to New Zealand.Tuatara resemble lizards, but are equally related to lizards and snakes, 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 diapsids (the group that additionally includes birds and crocodiles).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 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.Tuatara, like many of New Zealand's native animals, are threatened by habitat loss and the introduced Polynesian Rat (Rattus exulans).Taxonomy and evolution
2 Description
2.Behaviour
4 Conservation
4.Brothers Island tuatara
4.Taxonomy and evolution
Tuatara, and their sister group Squamata (which includes lizards, snakes and amphisbaenians), belong to the superorder Lepidosauria, the only surviving taxon within Lepidosauromorpha.The origin of the tuatara probably lies close to the split between the Lepidosauromorpha and the Archosauromorpha.Though tuatara resemble lizards, the similarity is mostly superficial, since the family has several characteristics unique among reptiles.The typical lizard shape is very common for the early amniotes; the oldest known fossil of a reptile, the Hylonomus, resembles a modern lizard.Tuatara were originally classified as lizards in 1831 when the British Museum received a skull.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.Now, most authors prefer to use the more exclusive order name of Sphenodontia for the tuatara and its closest living relatives.During the years since the description of the Rhynchocephalia, many disparately related species have been added to this order.This has resulted in turning the Rhynchocephalia into what taxonomists call a "wastebasket taxon".In 1925, Williston proposed the Sphenodontia to include only tuatara and their closest fossil relatives.Sphenodon is derived from the Greek for "wedge" (sphenos) and "tooth" (odon(t)).Tuatara have been referred to as living fossils.There was even a successful group of aquatic sphenodontians known as 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 of tuatara: Sphenodon punctatus and the much rarer Sphenodon guntheri, or Brothers Island tuatara, which is confined to North Brother Island in Cook Strait.The Brother's Island tuatara (S.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.Size comparison of tuatara 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.Both species are sexually dimorphic, males being larger.Brother's Island tuatara are slightly smaller, weighing up to 660g.Tuatara sexes differ in more than size.The spiny crest on a tuatara's back, made of triangular soft folds of skin, is bigger in males than in females, and can be stiffened for display.Skull of a tuatara, showing the complete temporal arches.However, in the tuatara, all the original features are preserved: it has two openings (temporal fenestra) on each side of the skull, with complete arches.In addition, in the tuatara, the upper jaw is firmly attached to the skull.Testudines (turtle and tortoise) skulls with their single temporal fenestrum are widely considered to be the most primitive among amniotes, though some research suggests they might have lost the temporal holes rather than never having had them.This is a tooth arrangement not seen in any other reptiles; although most snakes also 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.The tuatara's teeth are not replaced, since they are not separate structures like real teeth, but sharp projections of the jaw bone.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.Sensory organs
In tuatara, both eyes can focus independently, and are specialized with a "duplex retina" that contains two types of visual cells for vision by both day and night, and a tapetum lucidum which reflects on to the retina to enhance vision at night.The tuatara has a third eye on the top of its head called the parietal eye.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.Together with turtles, the tuatara has the most primitive hearing organs among the amniotes.The hair cells are unspecialized, innervated by both afferent and efferent nerve fibres, and respond only to low frequencies.This is the usual condition of fish vertebrae and some amphibians, but is unique to tuatara within the amniotes.They are found in some lizards (in lizards they are mostly made of cartilage), crocodiles and the tuatara, and are not attached to the spine or thoracic ribs.The real ribs are small projections, with small, hooked bones, called uncinate processes, found on the rear of each rib.The tuatara is the only living tetrapod with well developed gastralia and uncinate processes.The pelvis and shoulder girdles are arranged differently than in lizards, as is the case with other parts of the internal anatomy and its scales.Behaviour
Adult tuatara are terrestrial and nocturnal reptiles, though they will often bask in the sun to warm their bodies.Tuatara thrive in temperatures much lower than those tolerated by most reptiles, and hibernate during winter.The body temperature of tuatara is lower than that of other reptiles ranging from 5.Burrowing seabirds such as petrels, prions and shearwaters 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 beetles, crickets and spiders.Their diet also consists of frogs, lizards and bird's eggs and chicks.The eggs and young of seabirds that are seasonally available as food for tuatara may provide beneficial fatty acids.Tuatara will bite when approached, and do not let go easily.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.Tuatara reproduce very slowly, taking ten years to reach sexual maturity.Mating occurs in midsummer; females mate and lay eggs once every four years.Males do not have a penis; they reproduce by the male lifting the tail of the female and placing his vent over hers.It takes the females between one and three years to provide eggs with yolk, and up to seven months to form the shell.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.There is some evidence that sex determination in tuatara is determined by both genetic and environmental factors.The average lifespan is about 60 years, but they can live to be over 100 years old.Current distribution of tuatara (in black).Circles represent the North Island tuatara, squares the Brothers Island tuatara.However, kiore (Polynesian rats) had recently established on several of the islands, and tuatara were persisting, but not breeding, on these islands.Brothers Island tuatara
Sphenodon guntheri is present naturally on one small island with a population of approximately 400.Brothers Island tuatara were moved to Titi Island in Cook Strait, and their establishment monitored.Matiu Island, a more publicly accessible location.The captive juveniles were from induced layings from wild females.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 Straight.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.Moutoki Island to Moutohora.The carrying capacity of Moutohora is estimated at 8500 individuals, and the island could allow public viewing of wild tuatara.Eradication of rats
In 1990 and 1991, tuatara were removed from Stanley, Red Mercury and Cuvier Islands, and maintained in captivity to allow Pacific 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.Recovery Plan, published in 2001, states that eradication of rats from this island is pending.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.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.Tuatara at the Karori Wildlife Sanctuary are given coloured markings on the head for identification.Captive breeding
There are several Tuatara breeding programmes within New Zealand.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 Pukaha Mount Bruce Wildlife Centre keeps a pair and 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).Today, tuatara are regarded as a taonga (special treasure).The tuatara was featured on one side of the 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.Animal: The Definitive Visual Guide to the World's Wildlife.New York, New York: DK Publishing, Inc.Zoological Society of San Diego (2007).Threatened Species Recovery Plan Series No.Threatened Species Unit, Department of Conservation, Government of New Zealand.Threatened Species Unit, Department of Conservation, Government of New Zealand.Tuatara Factsheet (Sphenodon punctatus).Karori Sanctuary Wildlife Trust.Royal Forest and Bird Protection Society of New Zealand Inc.In: Halliday, Tim and Adler, Kraig (eds.The new encyclopedia of reptiles and amphibians, Oxford University Press, Oxford, pp."Early evolution of the venom system in lizards and snakes."The Tree of Life Web Project."Phylogeny" In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods.New Zealand Ecology: Living Fossils.Russell, Matt (August, 1998).Tuatara, Relics of a Lost Age.Dieter Sues (eds) In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods.Stearn, William T (April 1, 2004).Portland, Oregon: Timber Press Inc, p.New Zealand Frogs and reptiles.David Bateman publishing, pp."Notes on the Bones of a Species of Sphenodon, (S.Tuataras at Animal Corner."Turtles as diapsid reptiles.""Complete mitochondrial genome suggests diapsid affinities of turtles."Return of the Tuatara:A relic from the age of dinosaurs gets a human assist.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.Tuatara Reptile, New Zealand."Metabolism of tuatara, Sphenodon punctatus"."Reproductive cycles of male and female tuatara (Sphenodon punctatus) on Stephens Island, New Zealand"."Courtship, mating and male combat in Tuatara, Sphenodon punctatus".Neglected taxonomy and continuing extinctions of tuatara (Sphenodon).New Zealand Herald: Tuatara Release.The tuatara, Sphenodon punctatus Gray, on islands with and without populations of the Polynesian rat, Rattus exulans (Peale)."Rare tuatara raised at Wellington Zoo", 29 October 2007.Chapter 6: Traditional Kaitiakitanga Rights and Responsibilities.Wai 262 Report: Matauranga Maori and Taonga.Daugherty (2007) Species and Cultural Conservation in New Zealand: Maori Traditional Ecological Knowledge of Tuatara.Conservation of the Tuatara.Tuatara captive management plan and husbandry manual (PDF).Brothers Island tuatara (Sphenodon guntheri).All text is available under the terms of the GNU Free Documentation License.New Zealand was separated from the rest of
the world over 100 million years ago.The Kiwi, a flightless bird, is a symbol of
New Zealand.However, Tuatara is an even more primitive and distinctive animal than Kiwi.Tuataras survived because no predators invaded New Zealand.Tuataras are unusual reptiles, since they like cool weather.Invercargill environment (although they get a bit of help from oxytocin
injections).Tuataras do not live in lovely forest like this any more.The Maori rat (Kiore) made it impossible to live on the mainland.Tuatara melded with a misty,
Whirinaki Forest background.So, this is how Tuatara would have looked, before humans messed up the mainland
environment.Genetic testing has shown there are two species of tuatara: Sphenodon
Punctatus and S.There are also DNA subspecies, but lets not get involved with all that.Tuataras live separate from each other in well defended burrows.This is not safe for the birds, for wily Tuataras are partial to eggs and
chickens in spring time.Perhaps Tuatara tells the birds stories on rainy nights about him being
their ancient ancestor and having every right to live with them.Tuatara's relatives were the beak headed reptiles (Rhinocephalia).Tuatara (Sphenodon) is often used by zoologists as an example of
about as basic a reptile as they can find.The evolution of both reptiles and birds can be
described starting from tuatara anatomy.Tuataras are too lazy to chase their
prey.They just sit and if anything small is silly enough to pass by,
Tuatara suddenly snaps it up.Adult tuataras also enjoy eating young tuatara.The children emerge in daylight, when adults are often sleeping, which saves them
from a cannibal death.Snakes' teeth are like this too (acrodont).When eating slugs, teeth are not essential and
so old Tuataras get by very well.This is one of the reasons tuataras are not lizards.Crocodiles have thecodont teeth, which are set in the
bone.The female buries up to 19 soft shell eggs in soil, but not
often.No interest is taken in the eggs, which are left to
hatch by themselves just over a year later.Males are bigger than females and have bigger spines down their backs.Males can mate every year.So males fight vigorously over receptive females, and often show combat scars.Tuataras live for 60 to 100
years.The sex of Tuataras is decided by soil temperature around the
eggs.Warm soil causes males, cool soil leads to females.Other reptiles show this peculiarity too (crocodiles, turtles).Tuataras have three eyes, but the third eye is only tiny.It grows on top of the head, under the skin in adults, and has a retina with nerve
connection to the pineal.The amount of light falling on the third eye may trigger these biological cycles.There is a tiny extra hole in the skull for the third eye: called the parietal foramen
(although it is in the middle).We will review the big temporal foramina
shortly, since they are not eye sockets.Some scientists say the third eye has no function at all.This seems more a function of temperature than of light (since they live
underground).The next skull is synapsid, with one hole low in the temporal area.Modern reptiles, apart from turtles, are diapsid.They have two temporal holes behind the eye holes, giving even more bone for attaching the big jaw muscles.Tuataras show this complex arrangement very well and their skulls look like baskets as a result of it.No wonder they can bite hard.The brain box is little, because tuatara is not very clever and most of tuatara's skull is for eating, not thinking.That is where tuataras get the reputation of being related to dinosaurs.The arches bulge outwards slightly so the muscles have room to thicken as they contract.It is said the jaw elongated when reptile precursors, living in water, developed an appetite for big fish and had to open their mouths wide.The long nose was also useful for poking out of the water to breath.Crocodiles evolved from these).But a long jaw is harder to close and so the powerful biting muscles needed the bone arches to attach them to the skull.Tuatara eggs have an amnion.Humans nearly have the tuatara skull arrangement.The fibrous sheet is not there as a protection, but acts as an extra muscle attachment.Temporal muscle fibres are stuck very firmly to this membrane (temporal fascia).Don't you feel the subject has been
simplified by this concept?Sprawling tuatara, resting on his tummy.They move by wriggling, with just a little help from the
limbs.Some lizards have no legs and slither around like
snakes.The tuatara skeleton shows how the pelvic and shoulder
girdle articulations allow the animal to elevate its tummy off the ground.Much of a Tuatara's life is spent
sprawling.In dinosaurs the
front legs became fairly useless and often atrophied.University of Texas in Austin uses Computed Tomography to build digital models
of skeletons, including the Tuatara.Jessie Maisano, who kindly gave permission to use the picture.The reptile bone names have been added by John
Wattie.The industrial CT scanner used in Austin had a slice width of 20 microns.Management of foreign exchange riskIAS 39 consultancyCurrency overlayTreasury policies and reviews For more information please call George, Emma or Hils on 0800 100 301.The markets sprung into activity overnight after comments from US Federal Reserve Chairman
Ben Bernanke.Expectations are for interest rates to fall to at least 3.Tuatara Technology Limited, Auckland New Zealand All Rights Reserved.Hils Hunt formed Tuatara in 1991 and Mike Houlahan became a Director in 1993.Tuatara has remained privately owned, and both directors work within the company.Tuatara has a team of 15 including a specialist IT development department.Tuatara Technology Limited, Auckland New Zealand All Rights Reserved.Unauthorised use or reproduction is strictly prohibited.Tuatara are the only living members of an ancient order of reptiles that evolved around 225 million years ago.Their closest relatives all became extinct 65 million years ago.Tuatara have remained the same over 80 million years due to New Zealand's isolation, and this may be the reason they still survive.Tuatara are solitary animals although during the winter the young tuatara will huddle together.The males actively defend their territory but are less vigilant during the colder months.Tuatara reach sexual maturity at about 13 years of age.The average time between clutches can be up to four years.It is thought that adults stop growing at about 60 years of age but they can live longer than 100 years.Northern, Cook Strait and Brothers Island.Tuatara means 'old spiny back' in Maori.Tuataras have a third eye.Some scientists believe that this third eye may function as a light sensor, influencing the amount of time a tuatara spends basking.Tuatara teeth, also, are different from those of other reptiles.They have a single row of teeth in the lower jaw, and a double row in the upper jaw, the bottom row fitting neatly between the two upper rows.Little more than serrations of the jaw, they are not replaced when worn out or damaged, and some old Tuatara are virtually toothless, chewing their food between smooth jaw bones.The most populous island with tuatara is Stephens' Island, in Cook Strait.It was cleared for farming a long time ago and surprisingly the tuatara do very well in this environment.The sex of Tuataras is decided by soil temperature around the eggs.Adult tuatara are mainly nocturnal but the young come out during the day until they are about six months old, which reduces the chances of being eaten by an adult tuatara.Captive breeding is essential for the survival of some populations which share their island with rats, which can raid tuatara nests, eat baby tuatara and compete for tuatara for food.We hold a group of Cook Strait tuatara which are being studied for breeding purposes.On exhibit in the nocturnal house are Cook Strait tuatara called Spike and Spikette.Tuatara have a scaly loose skin which is soft to the touch.Brothers Island and has an olive skin with yellow spots.Bruce National Wildlife Centre. |
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