Consider the following statements 1. Dinosaurs roamed the earth during the Mesozoic era. 2. All Dindsaurus and other reptiles such as Ichthyosaur us and Pterosaurus became extinct due to unknown reasons in Triassic period. Which of the statements given above is/ are correct ?

Statement 1 is correct as the Mesozoic Era (252 to 66 million years ago) is widely known as the 'Age of the Dinosaurs' [t1][t2]. This era is subdivided into the Triassic, Jurassic, and Cretaceous periods, during which dinosaurs first appeared and eventually dominated terrestrial ecosystems [t2][t8]. Statement 2 is incorrect because the mass extinction of non-avian dinosaurs, pterosaurs, and marine reptiles like ichthyosaurs did not occur in the Triassic period. While a mass extinction occurred at the end of the Triassic, it primarily affected other groups [t1][t9]. The iconic extinction of dinosaurs and other large reptiles occurred at the end of the Cretaceous period, approximately 66 million years ago, due to a massive meteorite impact at the Chicxulub crater and volcanic activity [c1][c5][t3]. Therefore, only the first statement is accurate.

Sources

1. [1] https://www.wa.gov.au/organisation/department-of-mines-petroleum-and-exploration/geological-survey-of-western-australia/dinosaurs-and-other-giant-reptiles
2. [2] https://www.nhm.ac.uk/discover/when-did-dinosaurs-live.html
3. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 3: Geological Time Scale The Evolution of The Earths Surface > Cretaceous–Paleogene extinction event (Fifth Extinction – 66 mya) > p. 48
4. [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > Chicxulub Crater > p. 36
5. [5] https://www.usgs.gov/youth-and-education-in-science/mesozoic