All Angles Creatures
Squamata · XantusiidaeEntry 21,306 of 21,572

Reptilia · Squamata

Xantusia jaycoleiBezy, Bezy, Bolles, 2008

Cole's Night Lizard

No photograph of this species exists under a license anyone may reuse. It gets the same page regardless.

A ground-dwelling, active by day or night lizard from the Nearctic region, reaching 42 mm snout to vent.

Also called Cole’s Night Lizard.

ReptiliaSquamataXantusiidaeXantusia

Grows to
42mm
greatest recorded
Active
Cathemeral
Lives
Terrestrial
Weighs up to
1.42g
greatest
Body length across Xantusiidae

Longer than only 8% of all species in Xantusiidae anyone has measured.

8% of 36 species are smaller92% larger
36 mmthe whole family, smallest to largest153 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 36 to 153 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

24 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

The animal itself

Limbs
Four legs
Venomous
No
Fangs
None

Size

Length snout to vent · greatest recorded
42mm1.75 in

Shai Meiri, unpublished

Length snout to vent · adult female mean
40mm1.5 in
Largest female · snout to vent
40mm1.5 in

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

Body mass · greatestcomputed
1.42g0.05 oz

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

How it lives

Active
Cathemeral

probbaly mostly nocturnal (Rorabaugh and Lemos-Espinal 2016), cathemeral (Rodda 2020), Nocturnal (Ponce-Rosales et al. 2023)

Where it lives
Terrestrial

leaf litter (inferred from Noonan et al. 2013)

Biome
Deserts & Xeric Shrublands
Region
Nearctic
Mainland or island
Mainland
Highest it lives · above sea level
130m

0-129 (Rorabaugh and Lemos-Espinal 2016)

Range size
164km²

Breeding

Reproduction
Viviparous
Average clutch
4eggs

Naming and history

Suborder
Sauria
Infraorder
Scincoidea
Subspecies
No
Described by
Bezy, Bezy, Bolles
Moved to another genus · since it was first described
No
Described in
2008
Type locality
Mexico

Keeping one

6.5 in × 6.5 in × 4.25 in(17 × 17 × 11 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 1.75 in (42 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 Cole's Night Lizard. Rather than repeat a number from a care sheet, this page leaves it out.

Feeding

0kJ per day

Worked out for an animal of 1 g, the heaviest recorded for Cole's Night Lizard — 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 · snout to vent
  • Hatchling length · nose to tail
  • Largest juvenile · snout to vent
  • Largest juvenile · shell length
  • Egg length
  • Egg width
  • Body mass · a typical adult
  • Body mass · adult female, mean
  • Body mass at hatching
  • Longest recorded life
  • Preferred body temperature · chosen in a laboratory gradient
  • Body temperature when active · measured in the wild
  • Diet
  • Eats arthropods
  • Eats vertebrates
  • Eats plant matter
  • How it hunts
  • How the young develop
  • Gestation or incubation
  • Smallest clutch recorded
  • Largest clutch recorded
  • Mean clutch · smallest reported
  • Mean clutch · largest reported
  • 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
  • Conservation status
  • Status assessed · the year the Red List last looked
  • Population trend
  • Red List criteria
  • Active season · shortest recorded
  • Active season · longest recorded
  • Density · lowest recorded
  • Density · highest recorded
  • Home range · largest recorded
  • Habitat
  • Active in
  • Lowest it lives · above sea level

Others in Xantusiidae

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). Xantusia jaycolei. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/xantusia-jaycolei

@misc{xantusia_jaycolei_2026,
  title  = {Xantusia jaycolei},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/xantusia-jaycolei}
}

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.