Microlophus
Microlophus is a genus of tropidurid lizards native to South America. Around 20 species are recognized and 10 of these are endemic to the Galápagos Islands, where they are commonly known as lava lizards. The remaining, which often are called Pacific iguanas, are found in the Andes and along the Pacific coasts of Chile, Peru, and Ecuador.
The distribution of the lava lizards and their variations in shape, colour, and behaviour show the phenomenon of adaptive radiation so typical of the inhabitants of this archipelago. One species occurs on all the central and western islands, which were perhaps connected during periods of lower sea levels, while one species each occurs on six other more peripheral islands. All have most likely evolved from a single ancestral species. However, as usual for the Tropiduridae, they can change their colour individually to some extent, and members of the same species occurring in different habitats also show colour differences. Thus, animals living mainly on dark lava are darker than ones that live in lighter, sandy environments.
Evolution
Galápagos adaptive radiation
The genus Microlophus colonized the Galápagos archipelago on two separate occasions, both during the Pleistocene. Most of the Galápagos endemic species radiated from the first colonization event known as the Western radiation. Two species, M. bivittatus and M. habelii, radiated from the second colonization event, and are sister to the continental species M. occipitalis.Historically, the species M. albemarlensis was considered to occur on Isabela, Fernandina, Santiago, Santa Cruz, and Santa Fe islands. The species was later realized to actually be a species complex, and more recently, the Santiago, Santa Cruz, and Santa Fe populations have been given species status as M. jacobii, M. indefatigabilis, and M. barringtonensis, respectively. This restricts the range of M. albemarlensis to the Isabela and Fernandina islands.
Species
Listed alphabetically by specific name.| Species | Common name | Distribution | Image |
| Microlophus albemarlensis | Galápagos lava lizard, Isabela lava lizard | Galápagos | |
| Microlophus arenarius | Peru | ||
| Microlophus atacamensis | Atacamen Pacific iguana | Chile | |
| Microlophus barringtonensis | Santa Fe lava lizard | Galápagos | |
| Microlophus bivittatus | San Cristóbal lava lizard | Galápagos | |
| Microlophus delanonis | Española lava lizard, Hood lava lizard | Galápagos | |
| Microlophus duncanensis | Pinzón lava lizard | Galápagos | |
| Microlophus grayii | Floreana lava lizard | Galápagos | |
| Microlophus habelii | Marchena lava lizard | Galápagos | |
| Microlophus heterolepis | Chile, Peru | ||
| Microlophus indefatigabilis | Santa Cruz lava lizard | Galápagos | |
| Microlophus jacobii | Santiago lava lizard | Galápagos | |
| Microlophus koepckeorum | Frost's iguana | Peru | |
| Microlophus occipitalis | knobbed Pacific iguana | Peru, Ecuador | |
| Microlophus pacificus | Pinta lava lizard, common Pacific iguana | Galápagos | |
| Microlophus peruvianus | Peru Pacific iguana | Ecuador, Peru, Chile | |
| Microlophus quadrivittatus | four-banded Pacific iguana | Peru, Chile | |
| Microlophus slevini Torres-Carvajal, 2024 | Slevin’s lava lizard | Galápagos | |
| Microlophus tarapacensis | Tarapaca Pacific iguana | Chile | |
| Microlophus theresiae | Theresia's Pacific iguana | Peru | |
| Microlophus theresioides | corredor de pica | Chile | |
| Microlophus thoracicus | Tschudi's Pacific iguana | Peru | |
| Microlophus tigris | tiger Pacific iguana | Peru | |
| Microlophus yanezi | Yanez's lava lizard | Chile |
Nota bene: A binomial authority in parentheses indicates that the species was originally described in a genus other than Microlophus.