Crotaphytus antiquus
VENERABLE COLLARED LIZARD
Crotaphytus antiquus - Axtell & Webb 1995
IDENTIFICATION:
DISTRIBUTION:
Crotaphytus antiquus is known only from three small mountain ranges in the Mayrán (AKA Parras) Basin in the vicinity of Torreón, Coahuila, Mexico. These are the Sierra Solis, Sierra Texas and Sierra San Lorenzo.
HABITAT:
Crotaphytus antiquus occurs on the lower slopes of several extremely dry desert ranges. The desert is described as Chihuahuan and has essentially the same flora as the region around El Paso, Texas. Creosote is a common plant where this species occurs.
NATURAL HISTORY:
This species is saxicolous and is most often observed perched on rocks and rock outcrops. Male and female Crotaphytus antiquus display their breeding coloration in May and early June. Smaller lizards are a large part of the diet of most Crotaphytus, and the Venerable Collared Lizard is probably no exception. This species will bask during the heat of the day in temperatures that are too extreme for other lizards. Other species of lizard found in the habitat of C. antiquus are Sceloporus cyanostictus, Holbrookia maculata, Cophosaurus texanus, Aspidoscelis marmoratus variolosus, and Phrynosoma modestum. When frightened, collared lizards have the ability to run on their hind legs (bipedal motion) for short distances.
TAXONOMY:
This species is closely related to Crotaphytus reticulatus.
TYPE:
Described as Crotaphytus antiquus by Axtell and Webb (1995). Holotype: UTEP 15900. Type locality: 2.1 km N, 1.6 km E Vizcaya (25 46′ 04″N, 103 11′ 48″W, el 1100 m) in the Sierra Texas, Coahuila, Mexico. An adult male collected on 22 June 1978 by Eric C. Axtell and Ralph W. Axtell.
PERSONAL NOTES:
In July, 2007 Troy Hibbits and I visited the Sierra San Lorenzo to search for this species; we found a juvenile male, a spectacular adult male and an adult female C. antiquus on the lower slopes of the range. The juvenile was basking on the top of a boulder on the edge of a small draw while the adult male was flushed from beneath some thick brush where it had been concealed until our approach. The adult female was basking on a large rock and unlike the other two lizards, was extremely wary. We also observed many Sceloporus cyanostictus and several Cophosaurus texanus.
CONSERVATION STATUS:
The existance of Crotaphytus antiquus was kept a secret for many years after it’s discovery; the authors of the original description felt that “conservation by silence” was the best route to take at first. This species does have a very small natural range and could potentially be susceptible to overcollection. Fortunately, due to the isolation and arid nature of this species’ habitat, overcollection appears to be the only immediate threat to it’s existance. This species is probably not being collected except by permitted researchers, and then only in very limited numbers.
REFERENCES:
Axtell, R. W. and Webb, R. G. 1995. Two New Crotaphytus from Southern Coahuila and the Adjacent States of East-Central Mexico. Bulletin of the Chicago Academy of Sciences, Vol. 16(2):1-15.