Question

Land reptiles which went back into water about 200 mya to evolve into fish-like reptiles were :

• A. \( Ichthyosaurus \)
• B. \( Tyrannosaurus \)
• C. \( Stegosaurus \)
• D. \( Brachiosaurus \)

Hint:

Focus on the term "fish-like reptiles" and the time frame. Ichthyosaurs are the classic example of reptiles that adapted to marine life and developed a streamlined, fish-like body form through convergent evolution.

Answer 1

The Correct Option is A

Ichthyosaurs were a group of marine reptiles that evolved from terrestrial ancestors and adapted to a fully aquatic lifestyle. They appeared in the early Triassic period, around 250 million years ago, and thrived during the Mesozoic era. Their body shape was remarkably similar to that of modern fish and dolphins, an example of convergent evolution. They had streamlined bodies, paddle-like limbs for steering and stability, and a powerful tail for propulsion. The statement that they went back into water about 200 mya and evolved into fish-like reptiles accurately describes ichthyosaurs. The other options are incorrect: \begin{itemize} \item Tyrannosaurus was a large terrestrial carnivorous dinosaur from the late Cretaceous period. \item Stegosaurus was a large herbivorous dinosaur from the late Jurassic period, known for its plates along its back and spiked tail. \item Brachiosaurus was a giant herbivorous sauropod dinosaur from the late Jurassic period, characterized by its long neck and forelimbs longer than its hind limbs. \end{itemize}