Question

Dinosaurs became extinct in
A. Permian
B. Jurassic
C. Triassic
D. Cretaceous

Answer 1

Hint: The period in which dinosaurs became extinct was the last segment of the Mesozoic era and ended almost 65 million years ago. It lasted 79 million years and was succeeded by the Paleogene period.
In the early phases of this period, the configuration of continents was very different as compared to today’s arrangement. Towards the end of this period, it became similar to the modern configuration.

Complete answer:
- The Mesozoic era consisted of 3 periods and the Cretaceous period was the last of them. It was alSo, the longest segment of that era. The Cretaceous period succeeded the Jurassic period and was followed by the Paleogene period.
- As per palaeontological studies, the youngest trace of dinosaurs dates to around 65-66 million years ago and indicates their extinction period to be during the Cretaceous period.
- Based on the amount of metal iridium found in the layer of the Cretaceous period (K-PG layer), Luis and Walter Alvarez proposed that the dinosaurs became extinct due to a meteor hit.

Hence, the correct answer is option (D).

Additional information:
- Permian period: This was the last period of the Paleozoic era and spanned 47 million years. It was followed by the Triassic period.
- Triassic period: This was the first period of the Mesozoic era and lasted for 50.6 million years. It was succeeded by the Jurassic period.
- Jurassic period: This was the second period of the Mesozoic era and lasted 56 million years. This is followed by the last period of the era – The cretaceous period.

Note: Dinosaurs became extinct in the cretaceous period. Paleontological pieces of evidence like fossil bones, teeth, and other structures suggest that dinosaurs inhabited Earth for about 230 million years at least. The mass extinction of dinosaurs was accompanied by the extinction of marine and flying reptiles as well. This resulted in the removal of three-quarters of all life forms on Earth. Other than the meteor hit, some scientists even believe the lava from volcanic eruptions to be a reason for extinction.