Lessons from Fossils Flashcards
How old is the fossil of a footprint in Tanzania?
3.7 million years old.
What are fossils the remains of?
Fossils are the remains of plants or animals that lived many years ago. They have been preserved by natural processes.
What covers most dead animals and plants?
Sand, mud and dust cover the dead animals, plants, feces or footprints. This could happen when a river floods or volcano erupts. Then a fossil may form.
Who is Mary Anning
Mary Anning researched dinosaur feces and found fish bones inside them. This shows what some dinosaurs ate.
How is a fossil formed?
An animal dies and falls into mud or sand
More mud and sand buries it
Over time bacteria break down the soft parts of the body, only the teeth and skeleton remain
The mud and sand around the thing turns to rock
As rock forms, underground water rich with minerals seeps into the tiny gaps in the bones. Over time the minerals replace the bone making a hard copy
What rock are fossils found in?
Fossils are found in sedimentary rocks. Sedimentary rocks are formed in layers over millions of years. These layers are called strata.
What did William Smith find out?
200 years ago a miner, William Smith found out that different species are found in different strata.
What did Smith then do?
Smith looked around for evidence. He then shared his results with other scientists.
What was Smith’s explanation for the differently layered species?
Rock strata of the same age contain fossils of the same species. You can only find certain fossils in rock strata of a certain age.
What happened to do with fossils, in 1850?
In 1850 other scientists used Smith’s explanation to classify rock strata by the fossils they contained. By 1850 they had divided the Earth’s history into geological time periods.Each time period had it’s own Index fossil. The index fossil shows the relative age of the rock.
What are the 5 most recent time periods?
Triassic, Jurassic, Cretaceous, Tertiary, Quaternary.
