Fossils

major types of fossils

                Imprint- when an organism lies down on wet sediment and somehow the imprint of the organism remains after the organism is gone, like a foot print in cement

 

                Permineralized- when sediment fills the organisms soft and empty parts and other sediment completely covers the organism.  In this case the sediment takes on the shape of the organism, long after the organism has decayed

 

                Amber- when an organism is covered in Sap and the sap hardens into amber, the organism remains like a mummy inside of the amber stone…. This is useful for scientists because they can study the organisms DNA

 

The relative age of a fossil is a comparison of all of the fossils found on a particular area.  Those fossils found closer to the bottom beds of sediment are older.  Those fossils found near the top are younger.  We can not necessarily find out how old a fossil is with this process, but by comparing the areas the fossils are found, we can determine which is older and about how much older

 

Absolute age has to do with a fossils real age.  Scientists are able to do this by using chemicals and testing to find out the actual age of the fossil.  They do this by radioactive decay and looking at the half lives of the parts they break down.

 

The fossil record is an incomplete record of all fossils found. It is incomplete because, not all extinct creatures left fossils.