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Squamata · AnguidaeEntry 1,268 of 21,572

Reptilia · Squamata

Anniella geronimensisShaw, 1940

Baja California Legless Lizard

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

A burrowing, day-active, meat-eating lizard from the Nearctic region, reaching 165 mm snout to vent.

Reptilia › Squamata › Anguidae › Anniella

Grows to
165mm
greatest recorded
Eats
Carnivorous
Active
Diurnal
Lives
Fossorial
Body length across Anguidae

Longer than 70% of all species in Anguidae anyone has measured.

70% of 86 species are smaller30% larger
72 mmthe whole family, smallest to largest610 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 72 to 610 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

38 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
Endangered
Status assessed · the year the Red List last looked
2007
Population trend
Decreasing
Red List criteria
B1ab(iii)

The animal itself

Limbs
None
Venomous
No
Fangs
None
Preferred body temperature · chosen in a laboratory gradientmeasured
24.1°C
Body temp in the wild · mean, when active
25.9°C

body temperature of active animals in nature

Size

Length snout to vent · greatest recorded
165mm6.5 in

max 165 mm SVL (Feldman et al. 2016)

Length snout to vent · adult female mean
115.3mm4.5 in
Largest female · snout to vent
115.3mm4.5 in

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

Hatchling length · snout to vent
36mm1.5 in
Largest juvenile · snout to vent
36mm1.5 in
Body mass · greatestcomputed
7.82g0.28 oz

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

How it lives

Diet
Carnivorous

Insects (mostly termites, Pianka and Vitt 2003, see also Stebbins and McGinnis 2018)

How it hunts
Active foraging

Mesquita et al. 2016

Active
Diurnal
Where it lives
Fossorial

(e.g., Stebbins and McGinnis 2018)/Sand swimming (e.g., Lara-Resendiz et al. 2020)

Biome
Deserts & Xeric Shrublands
Active season · months of the year
8–9months
Region
Nearctic
Mainland or island
Mainland
Elevation · above sea level
90m

Lara-Resendiz et al. 2020

Range size
2930km²

Breeding

Reproduction
Viviparous
Average clutch
1eggs
Eggs or young per clutch
1–2eggs

1 (Alaniz-Garcia and Valdez-Villavicencio 2008), mean 1 (Mesquita et al. 2016), 1-2 (Stebbins and McGinnis 2018)

Mean clutch
1eggs

(Alaniz-Garcia and Valdez-Villavicencio 2008), mean 1 (Mesquita et al. 2016), 1-2 (Stebbins and McGinnis 2018)

Clutches a year
1per year

Naming and history

Suborder
Sauria
Infraorder
Anguimoprha
Subspecies
No
Described by
Shaw
Moved to another genus · since it was first described
No
Described in
1940
Type locality
Mexico

Keeping one

Baja California Legless Lizard is assessed as Endangered 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.

2 ft 2 in × 2 ft 2 in × 16.5 in(66 × 66 × 41 cm)

Minimum length × width × height, for one animal. Bigger is always better. Substrate at least 3.25 in (8 cm) deep.

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

Burrows, so substrate deep enough to dig in matters as much as floor area.

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 6.5 in (165 mm), at 4 × 4 × 2.5 times it, following the German federal welfare standard — how this is worked out.

In a laboratory thermal gradient this species settled at 75 °F (24.1 °C).

Preferred body temperature, recorded in a laboratory gradient where the animal could choose freely. 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.

1kJ per day

Worked out for an animal of 8 g, the heaviest recorded for Baja California Legless 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 · nose to tail
  • — 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
  • — Body temperature when active · measured in the wild
  • — Eats arthropods
  • — Eats vertebrates
  • — Eats plant matter
  • — How the young develop
  • — Gestation or incubation
  • — Clutches in a year
  • — 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
  • — Colour on the back
  • — Pattern on the back
  • — Pupil
  • — Sex decided by
  • — Density · lowest recorded
  • — Density · highest recorded
  • — Home range · largest recorded
  • — Habitat
  • — Active in

Others in Anguidae

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). Anniella geronimensis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/anniella-geronimensis

@misc{anniella_geronimensis_2026,
  title  = {Anniella geronimensis},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/anniella-geronimensis}
}

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.