Have you found some interesting fossils but are unsure how to identify them?
Are you confused about the difference between brachiopods and bivalves or crinoids and corals?
Skeletal support comes from protein collagen and spicules that are calcareous or siliceous.
Reproduction by sponges is by both sexual and asexual means.
It is almost unchanged since the days that it lived in those prehistoric swamps. They have hard diamond-shaped scales that form an interlocking armored body.
Lacking mouths, special cells form small pores that filter food from the sea as other cells form flagella that maintain a constant flow through a series of bodily channels.
Some sponges are radially symmetrical and others asymmetrical.
The resulting data, in the form of a calibration curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age.
Other corrections must be made to account for the proportion of throughout the biosphere (reservoir effects).