Tuesday, July 27, 2010
Sunday, July 25, 2010
Photo: Earliest Animals Were Sea Sponges, Fossils Hint
Fish glide past barrel sponges on a coral reef in an undated photo.
Sea sponges were thriving about a hundred million years before the evolutionary growth spurt that gave rise to modern animals, according to a February 2009 study. Fossil steroids produced by the sponges are now the oldest known fossil evidence of animal life, the study says.