The Jurassic period of the Mesozoic era is characterized by-
- Radiation of reptiles and origin of mammal-like reptiles
- Flowering plants and first dinosaurs appear
- Gymnosperms are dominant plants and first birds appear
- Dinosaurs become extinct and angiosperms appear
Answer
(3) Gymnosperms are dominant plants and first birds appear
Solution
The Mesozoic era has three periods: Triassic → Jurassic → Cretaceous.
⇒ Triassic: radiation of reptiles, first dinosaurs and mammal-like reptiles.
⇒ Jurassic: gymnosperms (conifers, cycads) are the dominant plants; dinosaurs at their peak; the first birds (Archaeopteryx) appear.
⇒ Cretaceous: flowering plants (angiosperms) appear; dinosaurs become extinct at its end.
∴ The Jurassic is characterized by dominant gymnosperms and the appearance of the first birds.
Answer: (3)