The discovery of the ancient sea sponge order Vilesida and its unique sterols is reshaping the understanding of Earth's earliest animal life, suggesting animals may have originated approximately 100 million years earlier than previously believed. Researchers connected Vilesida's sterol precursors to ancient steranes found in rocks from locations like Oman and Siberia, acting as biomarkers that indicate multicellular life existed long before the Cambrian explosion. This finding provides a crucial living comparison for molecular evidence previously found in ancient sedimentary records, altering the timeline of animal evolution by pushing back the potential emergence of simple, soft-bodied filter feeders.