"Living Dinosaurs" - Hexactinellid sponge reefs were frequent in the Jurassic but were thought to have died out together with the dinosaurs. They were however rediscovered as living reefs off British Columbia, Canada. See these fascinating new discoveries in a streaming video produced by GeoBio-Member PD Dr. Manfred Krautter and Coworkers. (recommended for DSL as minimum bandwith, data rate ca 55 KByte/s).
For more information: see " modern hexactinellid sponge mounds from the Canadian Arctic": M. Krautter's sponge-mound site