Empty seashells became the ocean’s first ready-made homes 470 million years ago

An international study led by scientists at the University of Tartu shows that about 470 million years ago, a major ecological change took place in the world’s oceans. For the first time, the hollow interiors of empty mollusc shells began serving as homes for small sea creatures. This marked the start of a brand-new way of living on the seafloor and was a major step toward how ocean ecosystems function today.The study, titled "Colonization of empty shells by cryptic fauna: a global event and important ecological innovation in Ordovician benthic ecosystems," was published in the journal Scientific Reports. The University of Tartu research team, including Olev Vinn, Oive Tinn, Liisa Lang, and Mare Isakar, examined fossils from different parts of the world to see how animals first moved into these shells.From empty structures to crowded communitiesIn today's oceans, an empty shell rarely stays vacant for long.