Reefs

Stromatolites, Stromatoporoids, sponges, corals & bryozoa

What environments did stromatolites grow in?

Saline (prevent animal grazing), muddy environments so cyanobacteria could draw in sediment to form the stromatolites.

What do spicules do in sponges?

act as a scaffold to support soft tissue, which enhances fossilization potential

What mineral do the spicules of sponges produce?

Silica

Name each of the types of Spicules in sponges

Monaxons, Triaxons, Tetraxons, Desmas, Polyaxons, Microscleres

This has a sophisticated structure

Stromatoporoid

What symmetry do the rugose corals possess?

Circular symmetry

Name the growth forms of rugose corals

ceratoidal, discoidal, cylindrical, scolecoidal, pyramidal, calceoloidal.

What body term can be applied to both mollusks and tabulate corals (also reduced in corals)?

Septa.

What feature do tabulate corals lack and why?

They lack an outer protective wall, because they are protected by surrounding sediment

What kind of symmetry do scleractinians show?

perfect radial symmetry