Question

What is the correct arrangement of periods of Palaeozoic era in ascending order in geological time scale ?

• A. Cambrian$\to$ Devonian$\to$ Ordovician$\to$ Silurian$\to$ Carboniferrous$\to$ Permian
• B. Cambrian$\to$ Ordovician$\to$ Silurian$\to$ Devonian$\to$ Carboniferous$\to$ Permian
• C. Cambrian$\to$ Ordovician$\to$ Devonian$\to$ Silurian$\to$ Carboniferrous$\to$ Permian
• D. Silurian$\to$ Devonian$\to$ Cambrian$\to$ Ordovician$\to$ Permian$\to$ Carboniferous

Answer 1

The correct option is B Cambrian$\to$ Ordovician$\to$ Silurian$\to$ Devonian$\to$ Carboniferous$\to$ Permian

Palaeozoic era is also called as “era of ancient life”. It is divided into six periods which are namely Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian period. Cambrian period (520-505 million yrs ago) is marked by establishment of invertebrate phyla as well as earlier vertebrates and dominant trilobites. Ordovician period (505-430 million years ago) is marked by appearance of first vertebrates and fungi as well as major extinction of marine species. Silurian period (430-410 million years ago) marked by origin of jawed fishes, wingless insects and terrestrial vascular plants. Devonian period (410-360 million years ago) is marked by origin of amphibians and diversification and dominance of fishes on earth. Carboniferous period (360-285 million years ago) is marked by origin of first reptiles and arthropods as well as abundance of horsetails, fern and seed bearing plants. Permian period (285-250 million years ago) is marked by abundance of primitive reptiles and appearance of conifers.

Therefore, the correct answer is option B.