Credit: Tumblr Blog Siphonophora:
Radiolarians are amoeboid protozoans, found throughout the oceans as zooplankton. Responsible for their intricate forms are the silica skeletons of which they are composed; basically, they are made of glass. Their skeletons litter the ocean floor, which is in fact mostly covered with them. This is called Siliceous Ooze. The earliest known radiolaria date back to the beginning of the Cambrian period- that’s about ~541 million years before present.












