The correct answer is option 1, which states that only statement 1 is correct.

Let`s analyze each statement:

Statement 1: Dinosaurs roamed the earth during the Mesozoic era.

This statement is correct. Dinosaurs were a group of reptiles that existed on Earth from about 230 million years ago to 65 million years ago, during the Mesozoic era. They were the dominant terrestrial vertebrates during this time.

Statement 2: All Dinosaurs and other reptiles such as Ichthyosaurs and Pterosaurs became extinct due to unknown reasons in the Triassic period.

This statement is incorrect. Although some reptiles, such as the Ichthyosaurs and Pterosaurs, became extinct during the Triassic period, it was not the cause of the extinction of all dinosaurs. The extinction event that wiped out the non-avian dinosaurs occurred at the end of the Cretaceous period, about 65 million years ago.

In summary, only statement 1 is correct. Dinosaurs did roam the Earth during the Mesozoic era. The extinction of all dinosaurs, including Ichthyosaurs and Pterosaurs, occurred at the end of the Cretaceous period, not the Triassic period.