
Ancient sea sponges in 541-million-year-old fossils could be Earth’s first animals even before dinosaurs |
For decades, scientists have debated which animals first appeared on Earth and set the stage for the evolution of complex life. A recent study by MIT geochemists offers compelling evidence that the earliest animals were not dinosaurs or the unusual creatures of the Cambrian explosion, but ancient ancestors of today’s sea sponges. These soft-bodied, ocean-dwelling…