Fossils

Fossils and Ancient Environments Fossils can tell us –The environment an animal lived in –The change in environment that may have occurred –The life style of the animal –The diet of the animal

Clues to Earth’s Past Geologic Time Scale is based on fossils Fossils are the remains of past life The best fossils are made from bones How fossils are made: –Animal dies –Bone gets buried by sediment –Sediment gets compacted –Sediment gets cemented –A sedimentary rock is made with the fossil as a part of it

Types of Preservation Replaced Remains –Permineralized remains Spaces in bone are replaced by minerals Some of the original material might be with the mineralized remains

Types of Preservation, cont Molds –Bone gets buried –The bone may decay or dissolve –The shape like the original bone is left –This makes a mold Cast –The mold gets filled with water, sediment or minerals –Filling this mold makes a cast

Types of preservation, cont. Original remains –Animal is buried really fast –No time for decay –Amber= bugs –Ice = woolly mammoth –All the original animal is preserved Trace fossils –Hand print, foot print, or other proof of activity –Trails, burrows and droppings are other examples –Shows an animal was once there

Index Fossils Fossils that –Lived a short period of time –World wide –Lots of animals –Easily Recognizable