At a certain point in Earth’s distant past, the planet’s assortment of organic molecules and compounds aligned to create the very first living organisms. However, a team of MIT geochemists believe that some 541 million-year-old chemical fossils embedded in sediment indicate that some of Earth’s earliest creatures were the ancient relatives of today’s sea sponges. In some cases, the sediment can have the right mixture of oxygen and other material that preserves a living organism’s biomolecules. In 2009, researchers from MIT detected what appeared to be first known chemical fossils of ancient sea sponges inside rock samples collected in Oman. If true, this implies that sponges first appeared earlier than almost any other lifeforms, making them among Earth’s first living creatures.