Sphenodon punctatusGray, 1842

Beakhead

Photograph by wild_wind, CC BY, via iNaturalist

A ground-dwelling, nocturnal, meat-eating reptile from the Australo-Pacific region, reaching 800 mm snout to vent.

Also called Beak-head, Brothers Island Tuatara, Cook Strait Tuatara.

Reptilia › Rhynchocephalia › Sphenodontidae › Sphenodon

Grows to: 800mm; greatest recorded
Eats: Carnivorous
Active: Nocturnal
Lives up to: 100years

What is known

30 sourced facts, each taken from a named scientific dataset. How to read these.

Cited from a dataset unless a row is marked otherwise.

Standing in the world

Conservation status: Least Concern

The animal itself

Colour on the back: Brown, Green
Pattern on the back: Uniform
Pupil: Round
Venomous: No
Fangs: None
Longest recorded life: 100years
Body temperature when active · measured in the wild: 20°C68 °F
Body temp in the wild · mean, when active: 16–21°C61–70 °F

Size

Length snout to vent · greatest recorded: 800mm2 ft 7 in
Largest female · snout to vent: 450mm17.5 in
Largest male · snout to vent: 610mm2 ft
Body mass · greatestcomputed: 1020g2.2 lb
Body mass · a typical adult: 430g15.2 oz

How it lives

Diet: Carnivorous
How it hunts: Active foraging
Active: Nocturnal
Where it lives: Terrestrial
Habitat: Forest, Shrubland
Region: Australo-Pacific
Elevation · above sea level: 1–722m

Breeding

Reproduction: Oviparous
Sex decided by: Temperature
Average clutch: 11.5
Clutches in a year: 0.22per year
Age at first breeding · female: 4380days

Naming and history

Subspecies: No
Described by: Gray
Moved to another genus · since it was first described: Yes
Described in: 1842

Keeping one

10 ft 6 in × 10 ft 6 in × 6 ft 7 in(320 × 320 × 200 cm)

Minimum length × width × height, for one animal. Bigger is always better.

The standard sizes ground-dwelling species at 4 × 4 × 2.5 times snout-vent length.

Mindestanforderungen an die Haltung von Reptilien (Sachverständigengutachten), German Federal Ministry for Nutrition, Agriculture and Forestry, Animal Welfare Division, 10 January 1997. The standard states these floor areas are recommendations rather than binding limits.

From this animal’s own snout-vent length of 2 ft 7 in (800 mm), at 4 × 4 × 2.5 times it, following the German federal welfare standard — how this is worked out.

Active animals measured in the wild averaged 68 °F (20 °C).

Mean body temperature of active individuals measured in nature. A measurement of the animal, not a setting for a thermostat.

Feeding

A prey item should be no wider than the space between the animal's eyes.

Widely used across reptile husbandry references. The stated reason is that the gap approximates the width of the throat, so wider prey is associated with impaction. This is established practice, not a measurement.

93kJ per day

Worked out for an animal of 1,020 g, the heaviest recorded for Beakhead — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.

An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.

What nobody knows

These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.

— Still living
— Length snout to vent · adult female mean
— Length snout to vent · adult male mean
— Length snout to vent · adult mean
— Length nose to tail · greatest recorded
— Female length · mean, nose to tail
— Length nose to tail · adult male mean
— Length nose to tail · adult mean
— Largest female · shell length
— Largest male · shell length
— Hatchling length · snout to vent
— Hatchling length · nose to tail
— Largest juvenile · snout to vent
— Largest juvenile · shell length
— Egg length
— Egg width
— Body mass · adult female, mean
— Body mass at hatching
— Preferred body temperature · chosen in a laboratory gradient
— Eats arthropods
— Eats vertebrates
— Eats plant matter
— How the young develop
— Gestation or incubation
— Smallest clutch recorded
— Largest clutch recorded
— Mean clutch · smallest reported
— Mean clutch · largest reported
— Clutches a year · fewest
— Clutches a year · most
— First breeds from · youngest recorded
— First breeds by · oldest recorded
— Hatchling length · smallest recorded
— Hatchling length · largest recorded
— Mature from · youngest recorded
— Mature by · oldest recorded
— Size at maturity · smallest recorded
— Size at maturity · largest recorded
— Limbs
— Status assessed · the year the Red List last looked
— Population trend
— Red List criteria
— Biome
— Active season · shortest recorded
— Active season · longest recorded
— Density · lowest recorded
— Density · highest recorded
— Home range · largest recorded
— Suborder
— Infraorder
— Type locality
— Active in
— Mainland or island
— Range size

Take this data

Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.

This species as JSON · the whole dataset

Cite this page

The Reptile & Amphibian Encyclopedia (2026). Sphenodon punctatus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/sphenodon-punctatus

@misc{sphenodon_punctatus_2026,
  title  = {Sphenodon punctatus},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/sphenodon-punctatus}
}

Sources

Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
AnAge, Human Ageing Genomic Resources (de Magalhães et al.), used under CC BY 3.0.
Moura, M. R. et al. TetrapodTraits: a database of 33,281 tetrapod species. Used under CC BY 4.0. Observed values only; this encyclopedia does not publish its imputed predictions.
Catalogue of Life (dataset 3LR), used under CC BY.