fossils

Question 1

what are fossils

Answer 1

the remains of animals or plants, footprints and burrows found in sedimentary rocks. animal either eaten or decomposes

Question 2

what information do fossils give us

Answer 2

different form of life that existed on earth also major changed in earths history

Question 3

what is fossilization

Answer 3

rare event, small chance of being preserved, some organisme have better chances bc: composition of skeletons or where they lived

Question 4

what info are lost in the fossilization process

Answer 4

internal organs, skin, hair, muscles etc..

Question 5

relative dating methods

Answer 5

analyze the layers or strata that build over time, layers are formed by sedimentary rocks, younger layers are on top or older layers.

Question 6

superposition:

Answer 6

oldest layer is at the bottom and youngest at the top

Question 7

relative dating:

Answer 7

comparing locations of fossils, does not give exact age but shows the order based on the stratigraphic layers

Question 8

absolute dating:

Answer 8

shows the age of the fossil, counting tree rings

Question 9

carbon dating:

Answer 9

uses radioactive isotope of carbon to determine how it decays over time

Question 10

order of geologic time scale

Answer 10

precambian, paleozoic, mesozoic, cenozoic

Question 11

important events in precambian

Answer 11

-formation of earth
-first sign life
-bacteria
-oxygen in atmosphere
-first aquatic soft-bodied organisms

Question 12

how long did the precambian era last

Answer 12

4 billion yrs

Question 13

important events in paleozoic

Answer 13

-aquatic invertabrates w hard shell
- large extinction of aquatic life
-plants, amphibians on dry land
-trees, reptiles
-largest mass extinction caused by glaciation

Question 14

how long did the paleozoic era last

Answer 14

300 million yrs

Question 15

important events in mesozoic

Answer 15

-warm climate, more large reptile
-extinction killing 50% of marine life
-first birds and small mammals
-dinosaurs
-extinction causing dinosaur disappear

Question 16

important events in cenozoic

Answer 16

-long cooling and drought period
-large mammals
-primates and hominids
-present