Reptilia · Squamata
Phrynosoma blainvilliiGray, 1839
San Diego Horned Lizard
Photograph placed in the public domain, CC0, via iNaturalist
A ground-dwelling, day-active, meat-eating lizard from the Nearctic region, reaching 114 mm snout to vent.
Reptilia › Squamata › Phrynosomatidae › Phrynosoma
- Grows to
- 114mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Diurnal
- Lives up to
- 10years
Longer than 83% of all species in Phrynosomatidae anyone has measured.
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
44 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
- Least Concern
- Status assessed · the year the Red List last looked
- 2016
- Population trend
- Decreasing
The animal itself
- Limbs
- Four legs
- Venomous
- No
- Fangs
- None
- Longest recorded life
- 10years
- Preferred body temperature · chosen in a laboratory gradientmeasured
- 37.6°C
- Body temperature when active · measured in the wild
- 34.9°C95 °F
- Body temp in the wild · mean, when active
- 34.9°C
Jennings and Hayes 1994: >8 (in captivity); 10 (http://www.californiaherps.com/lizards/pages/p.blainvillii.html)
mean body temperature of active individuals in nature
body temperature of active animals in nature
Size
- Length snout to vent · greatest recorded
- 114mm4.5 in
- Length snout to vent · adult female mean
- 78.2mm3 in
- Largest female · snout to vent
- 78.2mm3 in
- Hatchling length · snout to vent
- 27mm1 in
- Largest juvenile · snout to vent
- 27mm1 in
- Body mass · greatestcomputed
- 44.81g1.6 oz
- Body mass at hatchingmeasured
- 1g0.04 oz
max 114 mm (e.g., Heimes 2022)
snout-vent length; the source column mixes this with straight carapace length
computed from length by a family-level allometric equation, not weighed
How it lives
- Diet
- Carnivorous
- How it hunts
- Active foraging
- Active
- Diurnal
- Where it lives
- Terrestrial
- Habitat
- Forest, Grassland, Savanna, Shrubland
- Biome
- Mediterranean
- Active season · months of the year
- 7–8months
- Region
- Nearctic
- Mainland or island
- Mainland
- Highest it lives · above sea level
- 2440m
- Range size
- 216,647km²
- Density
- 236–277.1per hectare
insects (mostly ants, Jones and Lovich 2009, Stebbins and McGinnis 2018), arthropods, mostly ants (Heimes 2022),
Jones and Lovich 2009
e.g., Hult and Germano 2015
0-2438 (Stebbins and McGinnis 2018), near sea level to about 1700 (Heimes 2022)
Breeding
- Reproduction
- Oviparous
- Average clutch
- 15.5eggs
- Eggs or young per clutch
- 6–49eggs
- Mean clutch
- 12.4–15.5eggs
- Clutches in a year
- 1.5per year
- Clutches a year
- 1–2per year
- First breeds at
- 20–36months
6-21 (Stebbins and McGinnis 2012), 10-21 (Shaw 1952 n=2), 6-49 (Stebbins and McGinnis 2018), up to 10 (Grismer and Grismer 2022), Dominguez-Guerrero et al. 2022 (mean 12.4)
Naming and history
- Suborder
- Sauria
- Infraorder
- Pleurodonta
- Subspecies
- No
- Described by
- Gray
- Moved to another genus · since it was first described
- No
- Described in
- 1839
- Type locality
- Mexico
Keeping one
18 in × 18 in × 11 in(46 × 46 × 29 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 4.5 in (114 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 100 °F (37.6 °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.
6kJ per day
Worked out for an animal of 45 g, the heaviest recorded for San Diego Horned 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
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How the young develop
- — Gestation or incubation
- — 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
- — Red List criteria
- — Home range · largest recorded
- — Active in
- — Lowest it lives · above sea level
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). Phrynosoma blainvillii. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/phrynosoma-blainvillii
@misc{phrynosoma_blainvillii_2026,
title = {Phrynosoma blainvillii},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/phrynosoma-blainvillii}
}Sources
- Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
- Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
- Catalogue of Life (dataset 3LR), used under CC BY.