Question

According to the fossil record found in these sedimentary layers, what conclusion can be drawn about animal life in general?

Answer 1

B)Vertebrates appeared in the oceans before they moved on to land.

Answer 2

Answer:

Option (B)

Explanation:

The life first existed in the oceans. The marine vertebrates first occurred during the Cambrian explosion, about 500 million years back and these were the fishes. Over millions of years, these vertebrate fishes have undergone evolution forming more new complex species such as the amphibians that can live in both water as well as in the terrestrial areas. They occurred about 350 million years back. Thus, with the increasing time, more new species have developed and occupied a wide range of terrestrial areas.

These organisms after their death, their bodies are covered with sediments, removing from the oxygenated environment, providing the necessary condition for the preservation of fossils.

Thus, the vertebrate animals first appeared in the oceans then they have undergone evolution and were widely spread in the continental areas and the remains of these fossils are later found to be embedded in the sedimentary type of rock.

Hence, the correct answer is option (B).