All Angles Creatures
Squamata · PhrynosomatidaeEntry 9,467 of 21,572
Speckled Earless Lizard, Holbrookia approximans

Reptilia · Squamata

Holbrookia approximansBaird, 1859

Speckled Earless Lizard

Photograph by Juan Cruzado Cortés, CC BY-SA, via iNaturalist

A ground-dwelling, day-active, meat-eating lizard from the Nearctic region, reaching 72 mm snout to vent.

ReptiliaSquamataPhrynosomatidaeHolbrookia

Grows to
72mm
greatest recorded
Eats
Carnivorous
Active
Diurnal
Lives
Terrestrial
Body length across Phrynosomatidae

Longer than only 29% of all species in Phrynosomatidae anyone has measured.

29% of 168 species are smaller71% larger
47 mmthe whole family, smallest to largest175 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 47 to 175 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

26 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
72mm2.75 in

max 72 mm SVL (Feldman et al. 2016)

Length snout to vent · adult female mean
61.5mm2.5 in
Body mass · greatestcomputed
13.09g0.46 oz

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

How it lives

Diet
Carnivorous

invertebrates (Rodda 2020)

How it hunts
Active foraging

Active (Hernandez-Salinas et al. 2023)

Active
Diurnal
Where it lives
Terrestrial

e.g., Heimes 2022

Biome
Deserts & Xeric Shrublands
Region
Nearctic
Mainland or island
Mainland
Elevation · above sea level
1090–2480m

1091-2272 (Lemos-Espinal et al. 2013), 1200-2480 (Heimes 2022), max 2480 (Quintero-Diaz et al. 2017)

Range size
843,944km²

Breeding

Reproduction
Oviparous
Average clutch
9eggs
Eggs or young per clutch
9eggs

(n=1, Lemos-Espinal and Smith 2007, Lemos-Espinal et al. 2013, Rorabaugh and Lemos-Espinal 2016), up to 9 (Heimes 2022)

Naming and history

Suborder
Sauria
Infraorder
Pleurodonta
Subspecies
No
Described by
Baird
Moved to another genus · since it was first described
No
Described in
1859
Type locality
Mexico

Keeping one

11.5 in × 11.5 in × 7 in(29 × 29 × 18 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 2.75 in (72 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 Speckled Earless Lizard. 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.

2kJ per day

Worked out for an animal of 13 g, the heaviest recorded for Speckled Earless 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 female · snout to vent
  • 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
  • Eats arthropods
  • Eats vertebrates
  • Eats plant matter
  • How the young develop
  • Gestation or incubation
  • 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

Others in Phrynosomatidae

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). Holbrookia approximans. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/holbrookia-approximans

@misc{holbrookia_approximans_2026,
  title  = {Holbrookia approximans},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/holbrookia-approximans}
}

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.