Marine animals first colonized empty seashells about 470 million years ago‎

An international study led by researchers from the University of Tartu shows that approximately 470 million years ago, a significant ecological change took place in the world's oceans: For the first time, the interiors of empty mollusk shells began to be used as habitats. This marked the emergence of a new ecological niche and was a crucial step in the development of a marine ecosystem similar to today's.