Pretty amazing discovery, discussed in Smithsonian Magazine. It’s equally amazing that sponges are our oldest ancestors. And see here. And here.

Turner, now a field geologist at Laurentian University, is finally ready to step forward with her discovery: The spangled stones she found are sponge fossils dated at 890 million years old, placing sponges as the earliest prehistoric animal that humanity has ever found so far. Published today in the journal Nature, her findings suggest that animals popped up long before Earth was considered hospitable enough to support complex life.