Dating turritella fossil

Sponges reached their greatest diversity during the Cretaceous period. The genus Hydnoceras is considered a "glass sponge", which means it was composed of silica spicules, which provided structural support and deterred enemies.

Glass sponges are extant, but are now found only in the deep ocean.

This makes sense for two reasons- invertebrates are the most common fossils throughout North America, and they are inexpensive and cheap to use as samples during the event.

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This page contains information about all of the specimens you need to know for the event Fossils.

Of all the groups that you are responsible for knowing for this event, protists are the most under-represented.

You are responsible for knowing Fusulinids (usually the genus Fusulina) and the genus Nummulites.

Fusulinids are easily recognizable by their appearance- they appear to be grains of wheat.

They are omnivorous, eating via reticulopodia (cell extensions), which projected through pores in the test to catch small creatures.

Classification: Protista (kingdom), Foraminifera (phylum), Granuloreticulosea (class), Foramiferida (order), Fusilinidae (family), Fusilinids (genus) The name "nummulites" means "little coin" in Latin.The test of Nummulites is also spiraled, but does not form the same structure as that of the fusulinids. They date from the Paleocene to the Ogliocene epochs, and are commonly found in the Middle East, North Africa, Europe, and Asia.Nummulitic limestone was what was used to build the pyramids.Many forams lived benthically, but some were planktonic, and all were marine.They became much more common when coral reefs expanded, and would die off without them.The term 'diatomaceous earth' refers to sediment that is overwhelmingly composed of fossil diatoms.

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