Question

Jurassic period of Mesozoic era is characterised by
A) Flowering plants and first dinosaurs appear
B) Gymnosperms are dominant plants and first birds appear
C) Radiation of reptiles and angiosperms appear
D) Dinosaurs become extinct and angiosperm appear

Answer 1

Hint:The timeline of the Earth’s evolution includes three eras; the Paleozoic era, the Mesozoic era, and the Cenozoic era. These eras are divided by major mass extinction.

Complete answer:
To solve this question, we should know details about the Mesozoic era. The Mesozoic era is divided into; Triassic period that is 245-208 million years ago, the Jurassic period that is 208-146 million years ago, and the cretaceous period that is 146-65 million years ago. The Mesozoic era means the “middle animals' ', in this era the world fauns get changed drastically from the Paleozoic era. The Mesozoic era had the most popular organism that is dinosaurs; they evolved in the Triassic period but not diverse till the Jurassic period. The Mesozoic era had birds that did not get extinct but the dinosaurs got extinct at the end of the Cretaceous period. Some of the dinosaurs had lived in the late Cretaceous deposits in the United States Montana. For the terrestrial vegetation also the Mesozoic era was a great time for the change. The early Mesozoic was dominated by cycads, ferns, bennettitales, and other unusual plants. In the early Triassic period, modern gymnosperms like conifers appeared first and by the middle of Cretaceous, the earliest angiosperm had appeared and started to become diverse.
In the Mesozoic era, all the continents that are known today are combined into one large mass of land that is called Pangea and surrounded by a global ocean called Panthalassa. During the Jurassic period, the modern day Africa and South America get rift and start splitting the Pangea apart. Due to the abundance of evaporation, the Mesozoic era is considered to be a dry climate.
Now, the Jurassic period of the Mesozoic era is important as this period involves the dominance of the reptiles, dominance of the gymnosperm and the origin of first toothed birds.

Thus, the correct option is ‘B’. Gymnosperms are dominant plants and first birds appear.

Note:In the Mesozoic era the world’s largest mass extinction had occurred, many old organisms got extinct in the Permian extinction. This extinction includes the dinosaurs and mammals, and later the birds and flowers also get extinct.