Head to head
Twin-Spotted Spiny Lizard vs Blue Spiny Lizard
The twin-spotted spiny lizard and blue spiny lizard are both members of the large Sceloporus group, sharing the same robust, heavily scaled body plan but taking very different approaches to colouration and range.
| Twin-Spotted Spiny Lizard | Blue Spiny Lizard | |
|---|---|---|
| Scientific name | Sceloporus bimaculosus | Sceloporus serrifer |
| Distinguishing mark | Pair of dark shoulder blotches | Vivid blue body colouration in males |
| Relative size | Moderate | Larger, one of the bigger spiny lizards |
| Range within the US | Southwestern US | Only the southern tip of Texas |
| Primary range | Southwestern US and northern Mexico | Mexico, reaching just into Texas |
| Habitat | Desert grassland | Thornscrub and desert |
| Conservation status | Least Concern | Least Concern |
| Diet | Insectivore | Insectivore |
Twin-Spotted Spiny Lizard vs Blue Spiny Lizard: common questions
How can you tell a twin-spotted spiny lizard from a blue spiny lizard?
Size and colour settle it quickly: the blue spiny lizard is considerably larger and, in males, shows vivid blue colouration across much of the body, while the twin-spotted spiny lizard is a more moderately sized lizard identified mainly by a pair of dark blotches on the shoulders rather than any dramatic overall colouration.
Which of these two lizards is more common in the United States?
The twin-spotted spiny lizard has the broader US presence, occupying desert grassland across parts of the southwestern United States, while the blue spiny lizard reaches only the very southern tip of Texas, representing the northern edge of a range that extends much farther south through Mexico, where it is considerably more common.
Why is the blue spiny lizard so vividly coloured?
A male of this species uses its intensely blue colouration prominently in territorial disputes with rival males and in courtship displays directed at females, a bold visual signal quite different from the twin-spotted spiny lizard's subtler, more camouflage-oriented shoulder blotch pattern.