Reptiles of North Carolina
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Phrynosomatidae Members:
NC Records

Phrynosoma cornutum - Texas Horned Lizard

No image for this species.
Taxonomy
Class: Reptilia Order: Squamata Family: Phrynosomatidae
Taxonomic Comments: The genus Phrynosoma, the Horned Lizards, is endemic to North America and contains seventeen species, nine of which occur north of Mexico (SSAR, 2017; Powell et al., 2016). These species are all associated with prairie desert, or scrub habitats and have their native ranges located west of the Mississippi.
Species Comments: The Texas Horned Lizard is native to the western United States and exists in North Carolina solely as an introduced species.
Identification
Description: This striking species, with its crown of enlarged thorn like scales on its head and smaller spines covering the rest of its flattened body cannot be mistaken for any other of our lizard species. A photograph showing the head or the body can serve as the basis of a record for this species.
Field Marks: In addition to the prominent spines, this species is easily recognized by its wide flattened body and short tail. The ground cover ranges from yellowish to brownish, with a series of paired dark brown patches located on either side of a white mid-dorsal line.
Morphological Features: The head of this species has a row of small spines located transversly on its crown with two outer ones more strongly developed. two pairs of outward poining spines on are located on the lateral sides of the head and a pair of elongated, sharply pointed horns project rearward protecting the neck. The rest of the dorsal surface of the body bears smaller spines and a fringe consisting of a double of row of small triangular projections runs along the sides of the body. The total body length, including the short tail, is 2.5-7" (60-181mm) (Beane et al., 2010).
Field Guide Descriptions: Beane et al. (2010); Powell et al. (2016)
Online Photos:    Google   iNaturalist   GBIF
Observation Methods: This species is strictly diurnal and relies mainly on camouflage to avoid detection. If spotted, it typically remains stationary but it can run fairly fast if disturbed and will burrow into sand as a final attempt to escape.
Distribution in North Carolina
Distribution Reference: NCMNS Herpetology Collection Database (accessed 2023-01)
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: The habitats used by this species in its native range are dry flats supporting sparse vegetation. Areas in North Carolina where introduced populations have managed to persist are similar in their openness and possess the sandy substrates that this species uses for burrowing. The presence of ants is also a crucial habitat factor, particularly Harvester Ants that are a main prey item for this species.
Biotic Relationships: The species is an ant specialist and especially prefers the large Harvester Ants, despite their strong stinging abilities. The sharp spines on their heads give them substantial protection from snakes; if grabbed, they will swivel their heads driving their spines into the bodies of their persecutors. They can also squirt blood out of their eyes which also acts as a deterent.
Life History and Autecology
General Ecology
Community Ecology: This species may compete for food with Eastern Racerunners, who favor the same habitats, but their diet is more focused on ants than in that species.
Adverse Environmental Impacts
Effects of Introduced Species/Induced Increases of Native Species: Texas Horned Lizards may be declining in both their native ranges and in North Carolina as a result of the spread of the Red Imported Fire Ant. While adults appear to be immune to their stings and can escape from them by burrowing into sand, the Fire Ants may be responsible for eliminating colonies of Harvester Ants, the main food of this species. The ants are also known to attack the eggs of various species of lizards and snakes.
Interactions with Humans: The pet trade was responsible for great declines in the areas where Horned Lizards are native and also spread them into areas where they had little chance of survival in the wild.
Status in North Carolina
NHP State Rank: SE
Global Rank: G4G5
Protected Lands: There appear to be no records of this species from Hammocks Beach State Park, one area of protected land located near Swansboro, the area where this species appears to be still surviving. No records appear to exist from Camp Lejeune, which is also located fairly nearby.
Environmental Threats: Increased hurricane activity and sea-level rise may affect any populations that still remain in the Tidewater region of the state.
Status Comments: This species was introduced to North Carolina via the pet trade; Horned Lizards were extremely popular (Hall received one as pet on his fourth birthday in 1953) until the states where they naturally occur enacted laws protecting them from commercial exploitation. Only a few sites in our state have the combination of open sandy habitats and abundant ants -- mainly Harvester Ants -- that this species requires. Although we have records dating as far back as the 1920s and 30s, recent records have become increasingly scarce. There are no records in the NC Museum of Natural Sciences more current than 2001 (accessed 2023-02-12) but a specimen was found in Onslow County -- the county with the greatest number of records -- in 2021. The status of that population needs to be determined as does the fate of the populations once found further inland but not observed in decades.
Stewardship: Although not a native species, this fascinating species appears to be a completely benign introduction to our states fauna and any populations that still survive deserve at least some degree of protection, including from collection and protection of the small amounts of habitat that still support them.