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Squamata · GekkonidaeEntry 3,895 of 21,572
Great Rock gecko, Calodactylodes illingworthorum

Reptilia · Squamata

Calodactylodes illingworthorumDeraniyagala, 1953

Great Rock gecko

Photograph by Achintha de Zoysa, CC BY, via iNaturalist

A rock-dwelling, active by day or night, meat-eating gecko from the Oriental region, reaching 100 mm snout to vent.

Also called Illingworth's Gecko, Sri Lankan Golden Gecko.

ReptiliaSquamataGekkonidaeCalodactylodes

Grows to
100mm
greatest recorded
Eats
Carnivorous
Active
Cathemeral
Lives
Saxicolous
Body length across Gekkonidae

Longer than 90% of all geckos anyone has measured.

90% of 1,580 species are smaller10% larger
23 mmthe whole family, smallest to largest220 mm

The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 23 to 220 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.

What is known

35 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

Still living
Extant
Conservation status
Vulnerable
Status assessed · the year the Red List last looked
2019
Population trend
Decreasing
Red List criteria
B1ab(iii)

The animal itself

Limbs
Four legs
Venomous
No
Fangs
None

Size

Length snout to vent · greatest recorded
100mm4 in

max 100 mm SVL (Feldman et al. 2016)

Length snout to vent · adult female mean
81.5mm3.25 in
Largest female · snout to vent
81.5mm3.25 in

snout-vent length; the source column mixes this with straight carapace length

Hatchling length · snout to vent
31.5mm1.25 in
Largest juvenile · snout to vent
31.5mm1.25 in
Body mass · greatestcomputed
19.05g0.67 oz

computed from length by a family-level allometric equation, not weighed

Body mass at hatchingmeasured
0.7g0.02 oz

How it lives

Diet
Carnivorous

Arthropods (e.g., Das and Das 2017); insects (de Silva and Ukuwela 2017)

Active
Cathemeral

Crepuscular and nocturnal (e.g., de Silva and Ukuwela 2017) / Nocturnal (Wickramasinghe and Somaweera 2003)/cathemeral (Schmitz and Higham 2018)

Where it lives
Saxicolous

e.g., Das and de Silva 2011, de Silva and Ukuwela 2017, Werner et al. 2008; and Arboreal? Goonewardene et al. 2003

Habitat
Caves, Forest, Rocky, Savanna, Subterranean
Biome
Tropical & Subtropical Dry Broadleaf Forests
Region
Oriental
Mainland or island
Found only on islands
Elevation · above sea level
150–600m

150-600 (de Silva and Ukuwela 2017)

Range size
3987km²

Breeding

Reproduction
Oviparous
Average clutch
2eggs
Eggs or young per clutch
2eggs

Das and Das 2017, Werner et al. 2008

Mean clutch
2eggs

Naming and history

Suborder
Sauria
Infraorder
Gekkota
Subspecies
No
Described by
Deraniyagala
Moved to another genus · since it was first described
No
Described in
1953
Type locality
Sri Lanka

Keeping one

Great Rock gecko is assessed as Vulnerable on the IUCN Red List. Species at risk in the wild are often covered by CITES and by national law, which decide what may be bought, sold, moved across a border or kept at all — and captive-bred and wild-caught animals are usually treated differently. Check the rules where you are before acquiring one. Nothing below is a judgement about keeping this species; it is what a published welfare standard says about space, and what the animal itself was measured doing.

15.5 in × 15.5 in × 9.75 in(40 × 40 × 25 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.

Lives on rock, so stable hard surfaces and basking ledges suit it.

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 4 in (100 mm), at 4 × 4 × 2.5 times it, following the German federal welfare standard — how this is worked out.

No preferred body temperature has been recorded for Great Rock gecko. Rather than repeat a number from a care sheet, this page leaves it out.

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.

3kJ per day

Worked out for an animal of 19 g, the heaviest recorded for Great Rock gecko — 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.

  • 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 male · snout to vent
  • Largest female · shell length
  • Largest male · shell length
  • Hatchling length · nose to tail
  • Largest juvenile · shell length
  • Egg length
  • Egg width
  • Body mass · a typical adult
  • Body mass · adult female, mean
  • Longest recorded life
  • Preferred body temperature · chosen in a laboratory gradient
  • Body temperature when active · measured in the wild
  • Eats arthropods
  • Eats vertebrates
  • Eats plant matter
  • How it hunts
  • How the young develop
  • Gestation or incubation
  • Clutches in a year
  • 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
  • Age at first breeding · female
  • Mature from · youngest recorded
  • Mature by · oldest recorded
  • Size at maturity · smallest recorded
  • Size at maturity · largest recorded
  • Body temp in the wild · lowest mean recorded
  • Body temp in the wild · highest mean recorded
  • Colour on the back
  • Pattern on the back
  • Pupil
  • Sex decided by
  • Active season · shortest recorded
  • Active season · longest recorded
  • Density · lowest recorded
  • Density · highest recorded
  • Home range · largest recorded
  • Active in

Others in Gekkonidae

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). Calodactylodes illingworthorum. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/calodactylodes-illingworthorum

@misc{calodactylodes_illingworthorum_2026,
  title  = {Calodactylodes illingworthorum},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/calodactylodes-illingworthorum}
}

Sources

  1. Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
  2. Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
  3. Catalogue of Life (dataset 3LR), used under CC BY.