GEOLOGY

Detailed explanation-1: -In a scientific first, the results suggest that bivalves, a class of animals that includes clams and oysters, are most closely related to gastropods such as snails and slugs.

Detailed explanation-2: -The phylum Mollusca is the second-largest animal phylum, with over 100, 000 species. The molluscs include many familiar animals, including clams, snails, slugs, and squid, as well as some less familiar animals, like tusk shells and chitons (Fig. 3.51 A).

Detailed explanation-3: -The earliest undisputed gastropods date from the Late Cambrian Period, around 500 million years ago.

Detailed explanation-4: -Mollusks are a large group of invertebrate animals. Mollusks have soft bodies, and their bodies are not divided into rings like the segmented worms called annelids . Mollusks don’t have legs, though some have flexible tentacles for sensing their environment or grabbing things.