Biology Lecture, Ch 25 vocab

• the preserved remains of ancient organisms
• they can tell a great deal about body forms of organisms that lived long ago

• rocks formed by the accumulation of grains on the bottom of bodies of water
• if undisturbed, the oldest layer (strata) lies at the bottom while the newer at the top

a layer of sedimentary rock

a successive time interval in which half the remaining radioactive material of the radioisotope decays and becomes a different more stable isotope

• a method that relates the ages of rocks to patterns of Earth's magnetism (this changes over time)
• rocks preserve magnetic fields

the study of the movement of major land masses

the movement of lithospheric plates and the continents they contain

• caused by changing physical parameters
• when a large proportion of a species that are living at the time disappear.

an assemblage of all organisms of all kinds living at a particular time or place

all the plants living at a particular time or place

all of the animals living at a particular time or place

• 3 billion years ago
• shallow seas became populated with life
• life = microscopic prokaryotes (eukaryotes evolved 1/2 way through

• a rapid diversification of life
• happened before cambrian period

• vertebrates with well protected eggs that can be laid in dry places
• resulted from split of the terrestrial vertebrate lineage

A supercontinent created from all the continents that exists today being connected.

• Pangea divided into 2 and created this and Gondwana
• This was the northern half

• the other half that resulted from Pangea splitting into 2
• this is the southern half