Complex sentence: The cone snails or cone shells, sometimes simply known as "cones", (family Conidae), are a taxonomic family of approximately 500 medium-sized to large, sophisticated predatory sea snails, marine gastropod mollusks.
Split into simpler sentences: The cone snails or cone shells, sometimes simply known as "cones", are the popular name for snails or snail shells in the family Conidae, a taxonomic group of related organisms. Cone snails are medium-sized to large, sophisticated predatory sea snails, marine gastropod mollusks.