Q.12 A lizard like reptile which is considered as a “Living fossil” is:
1. Komado dragon
2. Varonus
3. Sphenodon
4. Gekko
Living Fossil Lizard-Like Reptile: Sphenodon (Tuatara)
Sphenodon, commonly known as the tuatara, is a rare reptile from New Zealand recognized as a “living fossil” due to its unchanged form since the Mesozoic era. The correct answer is 3. Sphenodon.
Correct Answer
Sphenodon belongs to the order Rhynchocephalia, the sole survivor of a group dominant 200 million years ago, earning its “living fossil” status for minimal morphological changes over geological time. Despite lizard-like appearance, it features a third “pineal” eye, slow metabolism, and lives over 100 years in New Zealand islands.
Option Explanations
1. Komodo Dragon (Incorrect)
The Komodo dragon (Varanus komodoensis) is the world’s largest lizard, native to Indonesian islands, known for venomous bite and recent evolution, not fossil-like stasis.
2. Varanus (Incorrect)
Varanus refers to monitor lizards, a diverse genus of active predators like the Asian water monitor; they represent modern squamate evolution, lacking ancient “living fossil” traits.
3. Sphenodon (Correct)
This nocturnal, oviparous reptile from New Zealand shows primitive features like a diapsid skull and acrodont teeth, unchanged since Jurassic times, distinguishing it from true lizards.
4. Gekko (Incorrect)
Gekko geckos are tropical house geckos with adhesive toe pads for climbing; they exemplify advanced squamate adaptations, far from “living fossil” status.
