Geckos are often mistaken for dinosaurs due to shared reptilian traits, such as scales. However, despite both being reptiles, their evolutionary histories followed distinctly separate paths for millions of years. Geckos are not dinosaurs.
Geckos: Lizards of Today
Geckos are a diverse group of lizards within the order Squamata and infraorder Gekkota. With over 1,500 species, they inhabit warm climates worldwide, from deserts to rainforests. These small reptiles typically range from 1.6 to 23.6 inches, possessing soft skin often covered in granular scales.
Many gecko species are nocturnal, with large eyes sensitive to low light, though some are active during the day. They can vocalize, producing chirps, clicks, or barks, which is uncommon among other lizards. Geckos are also known for their specialized toe pads, covered in millions of microscopic hairs called setae. These structures allow them to adhere to almost any surface, enabling them to climb vertical walls and walk across ceilings by utilizing Van der Waals forces.
Dinosaurs: A Look at the Past
Dinosaurs represent a diverse group of reptiles belonging to the clade Dinosauria. They first appeared during the Middle to Late Triassic period, approximately 243 to 233 million years ago. Following a major extinction event around 201 million years ago, dinosaurs became the dominant terrestrial vertebrates throughout the Jurassic and Cretaceous periods.
These ancient reptiles are distinguished by their hip structures and an upright posture, with legs positioned directly beneath their bodies, unlike the sprawling stance of most other reptiles. Dinosaurs varied immensely in size, from chicken-sized creatures to massive sauropods weighing over 100 tons. While many extinct groups were carnivorous or herbivorous, all dinosaurs laid eggs. Birds are the direct descendants of avian dinosaurs, representing the only dinosaur lineage that survived the Cretaceous-Paleogene extinction event.
Separate Evolutionary Journeys
Geckos and dinosaurs, despite both being reptiles, stem from different branches of the reptilian evolutionary tree. Their lineages diverged very early in reptilian history from a common reptilian ancestor. Dinosaurs belong to the Archosauria, a group that also includes modern crocodiles and birds.
Conversely, geckos are part of the Lepidosauria, an ancient lineage encompassing all lizards, snakes, and the tuatara. The evolutionary split between Archosauria and Lepidosauria occurred during the Triassic period, long before either geckos or dinosaurs reached peak diversity. Unambiguous gecko fossils date back to the Middle Jurassic (174 to 145 million years ago), indicating their presence alongside dinosaurs but as a distinct group. Geckos did not evolve from dinosaurs, nor are they “living dinosaurs” in the same way birds are; their shared reptilian ancestry makes them distant cousins, not direct descendants.