Scientists predict that sponges—among the most basic animals—arose a few hundred million years before the occurrence of the oldest confirmed fossil specimens, which date to about 500 million years ago ...

1. Identify a fossil as a sponge, archeocyathid, rugose, tabulate or scleractinian coral. 2. Know the skeletal structure and material of each of these animals. 3. Know the ecological characteristics ...

There are over 9,000 described species of sponge (Porifera) living in the ocean, from the intertidal zone all the way down to the abyss. These animals have long been providing for their underwater ...