Vocabulary
a rock is its age compared to the ages of other rocks
relative age
that layers with matching index fossils are the same age.
infer
rocord of the geologic events and the evolution of life forms as shown in the rock and fossil records
geologic time scale
is an animal with land plants
vertebrate
likely contributed to the mass extinction
factors
a rock is number of years that passed since the rock formed.
absolute age
is a gap in the geologic record
uncomformity
The paleozoic era life increased in complexity and pangaea formed
eras
is an animal that lives part of its life on land and part of its life in water
amphibian
area that is now india had weakend enviroments
hypothesize
to another rock and age in number of years since the rock formed
relative
the atoms of one element break down to form atoms of another element
radioactive decay
you can see in figure 2 that the Mesozoic era includes three periods
periods
have scaly skin and lay eggs that have tough, leathery shells
repile
it reaches on the surface
absorbed
determine the relative ages of sedimentary rock layers
law of superposition
IN radioactive dating scientists first determine the amount of a radioactive element in a rock sample.
radioactive dating
the geologic time scale
refine
many types of living things became extinct at the same time
mass entinction
the total energy of motionin the particles of a substance
Thermal energy
they most often occur in layers of sedimentary rock
fossils
this vast number of years into manageable periods scientists created the geologic time scale
organize
common invertbrates included jellyfish worms, sponges, clam like brachiopods and triobites
invertebrate
body temperture and feeds milk to its young
mammal
it escapes into space
green house