What the sources say
Texas Horned LizardPhrynosoma cornutum
Every figure, record and mechanism on the Texas Horned Lizard profile was written from a source, and this is the working table behind it: 47 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.
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Source
01
Animal Diversity Web, University of Michigan
Phrynosoma cornutum (Texas horned lizard). Animal Diversity Web, University of Michigan.
- The page saysturns its own eyes into blood-squirting weapons against predators
- The source says
These lizards can also squirt blood from their eyes, which they spray at predators.
- The page saysArid prairies, dunes, deserts and desert-basin edges
- The source says
Texas horned lizards reside in arid or semi-arid regions with access to open ground and some scattered vegetative cover. These areas include a number of early successional habitats like prairies, dunes, and deserts. They also include the edge habitat of playas, which are flat desert basins
- The page saysfrom the southern Great Plains and southwestern United States into northern Mexico
- The source says
Texas horned lizards (Phrynosoma cornutum) are distributed across the United States and Mexico ... as far west as southeastern Arizona and New Mexico. Texas horned lizards are commonly found throughout Oklahoma and Texas
Note: "Southern Great Plains" summarizes the account's Oklahoma/Texas/Kansas/southeast-Colorado range. - The page saysMainly harvester ants (Pogonomyrmex); ants were 69% of prey items in 351 stomachs, plus other insects
- The source says
The diet of Texas horned lizards mainly consists of harvester ants (Pogonomyrmex rugosus); however, if the opportunity arises, they will consume other insects. Pianka and Parker (1975) examined the stomach contents of 351 Texas horned lizards. Here, ants made up 69.0% of prey items found in these stomachs.
- The page saysBlood-squirting eye defense
- The source says
These lizards can also squirt blood from their eyes, which they spray at predators.
- The page saysa lizard is sexually mature once it measures at least 69 millimeters (2.7 inches) from snout to vent, females grow larger than males
- The source says
Upon reaching sexual maturity, the snout-vent length of Texas horned lizards measures a minimum of 69 mm. Female Texas horned lizards are larger than the males.
Note: 69 mm = 2.7 in. ADW's maximum lengths are not used: its prose gives females 144 mm and its table 69 to 114 mm, and neither says whether it is snout-vent or total length. - The page saysbody mass runs between 25 and 90 grams (0.9 to 3.2 ounces)
- The source says
Their mass ranges from 25 to 90 g.
Note: 0.88 and 3.17 oz (ADW's table) rounded to 0.9 and 3.2. - The page saysround-bodied, spike-crowned lizard of the arid prairies, dunes and deserts
- The source says
Texas horned lizards reside in arid or semi-arid regions with access to open ground and some scattered vegetative cover. These areas include a number of early successional habitats like prairies, dunes, and deserts.
- The page saysrunning from southeastern Colorado and southwestern Missouri down through Oklahoma and Texas
- The source says
Their range extends as far north as southeast Colorado, Kansas, and southwest Missouri. ... Texas horned lizards are commonly found throughout Oklahoma and Texas
- The page saysinto northern Mexico
- The source says
They live as far south as the Mexican states of northeast Sonora, Chihuahua, Durango, Zacatecas, San Luis Potosí, and Tamaulipas.
Note: "Northern Mexico" summarizes these named Mexican states. - The page saysTwo brow horns crown its head, more spikes run along its jaw, and two rows of spines line its flanks
- The source says
The largest horns crown their heads: two form the brow, while more protrude from the jawline and up to the temporal portion of the skull. Two rows of spikes line the lateral portions of their torso
- The page saysIf a threat keeps coming, the lizard hisses and lunges, and it can also
- The source says
If the threat approaches, they will hiss and lunge to defend themselves. These lizards can also squirt blood from their eyes, which they spray at predators.
- The page saysraise the blood pressure inside its sinus orbitalis, a sinus in the eye socket, until a blood vessel ruptures and a passage opens into the conjunctival sac, so blood sprays out at the predator
- The source says
They do this by forcing the blood pressure within the sinus orbitalis to increase, causing the blood vessel to rupture and forcing a passage to be formed into the conjunctival sac.
Note: "A sinus in the eye socket" glosses orbitalis (of the orbit). "Until" paraphrases "causing". - The page saysOne individual studied by Burleson in 1942 squirted blood from its left eye across nearly a meter
- The source says
An individual studied by Burleson (1942) ejected blood from its left eye at a distance of nearly 1 meter.
- The page saysThe lizard builds the pressure itself until the vessel gives way
- The source says
forcing the blood pressure within the sinus orbitalis to increase, causing the blood vessel to rupture
- The page saysthen sprays the blood at predators
- The source says
which they spray at predators.
- The page saysWhen Pianka and Parker opened the stomachs of 351 of these lizards, 69.0% of the prey items were ants
- The source says
Pianka and Parker (1975) examined the stomach contents of 351 Texas horned lizards. Here, ants made up 69.0% of prey items found in these stomachs.
- The page saysA single lizard can take from about 30 to more than 100 ants a day
- The source says
A single Texas horned lizard can consume from about 30 to over 100 ants per day.
- The page sayswaiting at a colony entrance, tilting its head sideways and down, and lapping them up with a sticky tongue
- The source says
Texas horned lizards have been observed waiting at colony entrances of harvester ants between the hours of 0900-1100 h ... To catch their prey, Texas horned lizards tilt their heads sideways and downwards, then quickly lap them up into their mouths with their sticky tongues.
- The page saysIts horns are thought to be a defense: they have been found puncturing the throats of canids (the dog family), rattlesnakes, whipsnakes, falcons and hawks that preyed on it
- The source says
It is thought that the horns of horned lizards are used to defend against predators. The horn of this species have been found puncturing the throats of all listed species except greater roadrunners.
Note: ADW's Known Predators list: Canids, western diamondback rattlesnake, sidewinder, Sonoran whipsnake, coachwhip, prairie falcon, American kestrel, loggerhead shrike, red-shouldered hawk, greater roadrunner. - The page saysThe greater roadrunner is the listed exception: it crushes the lizard's skeleton against a rock, then eats it head first
- The source says
Greater roadrunners kill Texas horned lizards by crushing their skeletons against a rock, then consuming the lizard head first, a method of consumption which has allowed them to avoid the same fate.
- The page saysit has declined throughout central Oklahoma and Texas since the 1960s
- The source says
Since the 1960s, they have declined throughout central Oklahoma and Texas.
- The page saysWithin Texas, though, urban growth over its habitat, collection as pets and pesticides reducing the harvester ants it eats have all contributed to its decline
- The source says
the urbanization of their habitat, collection as pets, and the loss of their main food source have all contributed to their decline. Harvester ants (Pogonomyrmex rugosus) make up 69% of their diet, but they are facing a decline due to the use of pesticides.
- The page saysNearly a meter: one lizard studied in 1942 shot blood that far from its left eye
- The source says
An individual studied by Burleson (1942) ejected blood from its left eye at a distance of nearly 1 meter.
- The page saysIt raises the blood pressure in a sinus in its eye socket until a blood vessel bursts, and the blood is forced into the pocket between eyelid and eyeball
- The source says
They do this by forcing the blood pressure within the sinus orbitalis to increase, causing the blood vessel to rupture and forcing a passage to be formed into the conjunctival sac.
Note: "The pocket between eyelid and eyeball" glosses the conjunctival sac. - The page saysMostly harvester ants, plus other insects when the chance comes
- The source says
The diet of Texas horned lizards mainly consists of harvester ants (Pogonomyrmex rugosus); however, if the opportunity arises, they will consume other insects.
- The page saysAnts were 69% of the prey items researchers counted in the stomachs of 351 lizards
- The source says
Pianka and Parker (1975) examined the stomach contents of 351 Texas horned lizards. Here, ants made up 69.0% of prey items found in these stomachs.
- The page saysone lizard eats roughly 30 to over 100 ants a day
- The source says
A single Texas horned lizard can consume from about 30 to over 100 ants per day.
- The page saysLow
- The source says
The only harm Texas horned lizards can do to humans is bite. While normally a docile species, Texas horned lizards may lunge at a human if threatened.
- The page saysit can inflate itself with air so the spikes stand out, making it harder for a predator to eat
- The source says
They can also inflate themselves full of air so their spikes protrude, making them more difficult for predators to consume.
- The page saysIts diet is mainly harvester ants
- The source says
The diet of Texas horned lizards mainly consists of harvester ants (Pogonomyrmex rugosus)
- The page saystags: camouflage
- The source says
Depending upon the geographic region, Texas horned lizards will have coloration that resembles the color of the ground.
Note: Settles #732: ground-matching coloration by region fits the tag definition (coloration that blends the animal into surrounding terrain). - The page saysit forces up the blood pressure behind its eye until a vessel ruptures and blood sprays nearly a meter at the predator
- The source says
An individual studied by Burleson (1942) ejected blood from its left eye at a distance of nearly 1 meter. They do this by forcing the blood pressure within the sinus orbitalis to increase, causing the blood vessel to rupture
Note: vibe.reason, settled in #732 (was geography and mood).
Source
02
Hammerson 2007
Hammerson (2007). Phrynosoma cornutum. The IUCN Red List of Threatened Species 2007: e.T64072A12741535.
- The page saysLeast Concern
- The source says
IUCN Red List category: Least Concern (LC).
Note: Category checked through GBIF's copy of the Red List, as iucnredlist.org refuses scripts; the assessment DOI is the cited reference. - The page saysThe IUCN Red List rates the Texas horned lizard Least Concern
- The source says
IUCN Red List category: Least Concern (LC).
- The page saysThe IUCN Red List rates it Least Concern
- The source says
IUCN Red List category: Least Concern (LC).
Source
03
Comanns et al. 2011
Comanns et al. (2011). Moisture harvesting and water transport through specialized micro-structures on the integument of lizards. Beilstein Journal of Nanotechnology.
- The page saysA honeycomb-shaped microstructure on its scales makes the skin superhydrophilic
- The source says
the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable
- The page saysa droplet spreads almost instantly and soaks into a network of capillary channels running between the scales
- The source says
an almost immediate spreading of the droplet on the moisture harvesting animals, i.e., Moloch horridus, Phrynocephalus arabicus and Phrynosoma cornutum can be seen
- The page saysthose channels are wired to favor one direction
- The source says
the velocity towards the mouth, i.e., rostral is significantly higher than for all other directions
- The page saysin lab tests, water moving toward the mouth flowed at about 3.15 millimeters a second, against roughly 1.6 to 1.8 millimeters a second sideways or toward the tail
- The source says
P.c. 3.15 ± 0.94 / 1.84 ± 0.24 / 1.61 ± 0.45
Note: Table 1's average water transport velocity (mm/s) for Phrynosoma cornutum (P.c.): rostral / lateral / caudal, measured in the first 333 ms after applying water. - The page saysIts scales carry a microscopic honeycomb texture that makes water spread across them rather than bead
- The source says
All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales
Note: "Spread rather than bead" glosses superhydrophilic (claim 24). - The page saystiny channels between the scales then move that water toward its mouth faster than in any other direction
- The source says
the velocity towards the mouth, i.e., rostral is significantly higher than for all other directions
Note: "Faster" paraphrases the source's "significantly higher" velocity; same comparison (mouthward vs. every other direction).
Source
04
Comanns et al. 2015
Comanns et al. (2015). Directional, passive liquid transport: the Texas horned lizard as a model for a biomimetic 'liquid diode'. Journal of The Royal Society Interface.
- The page saysskin channels that steer water toward its snout
- The source says
their skin is capable of collecting and transporting water directionally by means of a capillary system between the scales. This fluid transport is passive ... and directs water preferentially towards the lizard's snout.
- The page saysNo muscles or pumping are involved, just channels that narrow and widen along the way
- The source says
This fluid transport is passive, i.e. requires no external energy ... based on geometric principles, namely on a periodic pattern of interconnected half-open capillary channels that narrow and widen.
- The page saysIts skin also collects water from sources such as moist sand and dew
- The source says
Special skin adaptations enable them to access water sources such as moist sand and dew
Source
05
Sherbrooke & Kimball 2024
Sherbrooke & Kimball (2024). Antipredator Blood-Squirting Defense in Horned Lizards (Phrynosoma): Chemical Isolation of Plasma Component(s), Pogonomyrmex Ant Dietary Origin, and Evolution. Ichthyology & Herpetology.
- The page saystags: toxic-chemical
- The source says
squirt systemic blood from circumocular sinuses during encounters with certain mammalian predators. The predators react with distinct revulsion.
Note: Settles #732: the aversive plasma compound comes from its Pogonomyrmex ant diet (same abstract: "Plasma fractions from individuals of P. cornutum, a blood-squirting species, fed Pogonomyrmex had more aversive levels of the active compound(s) compared to those given a cricket diet").
Source
06
Lara-Reséndiz et al. 2015
Lara-Reséndiz et al. (2015). Thermoregulation of two sympatric species of horned lizards in the Chihuahuan Desert and their local extinction risk. Journal of Thermal Biology.
- The page saysA 2015 study measured its body temperatures at three Chihuahuan Desert sites in Mexico and fed them into an extinction model: if air temperatures rise as climate models predict, it projected local extinction at 6% of sites within the species' current range by 2050 and 18% by 2080
- The source says
at three contrasting Chihuahuan Desert sites in Mexico. Using these physiological data, we estimate local extinction risk under predicted climate change within their current geographical distribution. ... if air temperature rises as predicted by climate models, the extinction model projects that P. cornutum will become locally extinct at 6% of sites by 2050 and 18% by 2080
Note: 2015 is the paper's publication year (Journal of Thermal Biology, 2015). "Projected" keeps the model's hedge.
How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.