When did mollusks become a thing?

Mollusks have been around for hundreds of millions of years. The earliest known mollusks date back to the Precambrian period, around 550 million years ago. These early mollusks were small, worm-like creatures that lived in the oceans. Over time, mollusks evolved into a wide variety of forms, including clams, snails, and squid. Today, mollusks are one of the most successful groups of animals on Earth, with over 100,000 known species.