Mesozoic

Hint: Dinosaurs are extinct species of reptiles that had appeared during the Mesozoic era.Complete answer: The above mentioned periods are geological time scales. 1. A method of chronological dating that classifies geological strata in time is the geologic time scale (GTS). It subdivides all time into named units of abstract time called eons, times, cycles, epochs, and ages in descending order of length. 2. Geological Time Scale is used to define the timing and relationships of events in geological history by geologists, paleontologists, and other earth scientists. 3. An era refers to a particular geologic time subdivision that divides an ‘eon’ into smaller units of time. Dinosaurs are a complex group in the Dinosauria clade. They are considered to be reptiles. 4. The second section of the Mesozoic Era was the Jurassic Period that occurred after the Triassic Period and before the Cretaceous Period. It was approximately 199.6-145.5 million years ago. 5. During the Jurassic period, the arid conditions typical to the Triassic gradually changed. 6. The hot and humid conditions of the Jurassic period allowed lush vegetation to cover much of the landscape. So, the correct answer is “Option B”.Note: According to the macroscopic fossil record, the Palaeozoic, Mesozoic, and Cenozoic eras reflect \"old life,\" \"middle life\" and \"recent life\" respectively. Scientists split the Mesozoic Era into three phases: the Triassic, Jurassic, and Cretaceous periods. Often the whole Mesozoic Era is called the age of dinosaurs but the first dinosaurs appeared in the Jurassic period.