Mistaken Identities: Lizards vs. Salamanders

Lizards and salamanders are both ectotherms—meaning their body temperature is controlled by external sources—with similar body shapes, but that's about where the similarities end. In fact, they diverged fairly early on the family tree of the animal kingdom. Lizards, along with snakes, turtles, crocodilians and tuataras, are reptiles (belonging to the class Reptilia). As amphibians, salamanders are in the class Amphibia, which also includes frogs, toads and caecilians.

This major divergence in classification is just scratching the surface of the differences between these two seemingly similar vertebrates!

Other Differences

When it comes to lizards and salamanders, there are more differences than meets the eye.

Habitats

Lizards live in a wide variety of terrestrial habitats across the globe and are found on every continent except Antarctica. As amphibians, salamanders dwell in aquatic habitats or in moist terrestrial habitats, like woodlands.

Breathing Methods

Unsurprisingly, as terrestrial animals, lizards breathe with lungs—but it's not so simple for salamanders. Some species of salamander breathe through lungs in addition to their skin and mouth lining, while other species lack lungs and rely on their skin and mouth lining for respiration. Fully aquatic species of salamander and aquatic larvae breathe through their skin and many species have external gills.

Reproduction

Lizards typically lay shelled eggs on land, although some species are viviparous, meaning they give birth to fully developed young. Most salamanders, on the other hand, lay non-shelled eggs; the one exception is the European fire salamander, which gives birth to fully developed young. Some salamander species lay their eggs in water; these eggs will hatch into aquatic larvae. Other species of salamander will lay their eggs on land; these young do not have an aquatic larval stage.

Diurnal vs. Nocturnal

Most species of lizard are diurnal, meaning they're active during the day—although there are some lizards, like geckos, that are nocturnal and active at night. All salamanders, however, are nocturnal.

Diet

When it comes to diet, lizards run the gamut: Some are carnivores and eat only other animals, some are herbivores and eat only plants, and some are omnivores and eat both. Salamanders are strictly carnivorous, feeding on a typical diet of earthworms, insects and other small invertebrates. Some larger species of salamanders include smaller salamanders and other vertebrates in their diet.