Longtail Spiny Lizard

Longtail Spiny Lizard, Sceloporus siniferus

Longtail Spiny Lizard, Sceloporus siniferus. Lizards photographed in Parque National Huatulco, Huatulco, Oaxaca, March 2021. Photographs and identification courtesy of Marina Sutormina, Stockholm, Sweden.

The Longtail Spiny Lizard, Sceloporus siniferus, is a member of the Iguanidae family. The Iguanidae family consists of seven hundred members placed in forty genera. There are one hundred species in the Sceloporus genus. The Longtail Spiny Lizard is known in Mexico as Lagartija-escamosa Cola Larga.

Longtail Spiny Lizards have slender, elongated bodies that are covered in coarse, keeled scales. Their skin displays a blend of light gray and brown colors on their dorsal side with a lighter brown ventral surface. One distinguishing feature are two rows of fringed scales under their toes that aid in climbing. Sexual dimorphism is displayed with males weighing larger, possessing longer heads, and displaying a different scale pattern than the females. Females typically display a dorsal zigzag pattern whereas the males typically display two dorsal light colored stripes. Ventrally, the males may show some sexual dimorphism with an orange coloration in their gular region. They can grow up to approximately 6 cm (2.4 inches) in snout-to-vent length.

The Longtail Spiny Lizard is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, habitat use, and reproduction. However, it is known that this species is capable of reproducing throughout the year and can lay multiple clutches each breeding season. Additionally, they feed on various insects, larvae, and plant matter.

The Longtail Spiny Lizard is endemic to Mexico, where it ranges from western Guerrero along the Pacific Coast to eastern Chiapas. They have been found at elevations from sea level to approximately 2,400 m (7,900 feet). They inhabit dry forest and oak forest, including disturbed areas.

The Longtail Spiny Lizard may be confused with the Mesquite Lizard, Sceloporus grammicus, due to their similar appearances and overlapping ranges. These species can be differentiated visually. The Mesquite Lizard varies in coloration from dark grayish-brown to olive or green with a series of indistinct dark crossbands along their dorsal side. Additionally, males often display vibrant patches of blue on their gular region during breeding season.

From a conservation perspective, the Longtail Spiny Lizard is currently considered to be of Least Concern due to their wide distribution and presumed large population size. There appear to be no major threats to this species.