Fossil Vocabulary
1.) Paleontologist (70) – Scientist who studies fossils.
2.) Principle/ Law of Superposition (78)In undisturbed layers of rock, the oldest layers are
found on the bottom and the youngest on the top.
3.) Relative Age/ Dating (79) - Its age in comparison
to the age of other things.
4.) Index Fossil (75) The remains of species that existed on Earth for
relatively short periods of time, were abundant, and
were widespread geographically.
5.) Trilobites (100/105) - Small, hard-shelled
organisms that crawled on the seafloor and
sometimes swam through the water. They are
considered to be index fossils.
6.) Extinction Causes:
Natural Causes- Meteorite colliding with Earth,
Mass volcanic activity, draught, climate change
(leading to loss of vegetation/habitat), Intro. Of
predator due to natural causes i.e. migration
Man-made CausesPollution, Deforestation/Habitat destruction,
Hunting, New predators
7.) Geologic Time Scale (100) – The division of Earth’s
history.
8.) Era (101) - Next to Eons, the longest subdivisions,
which are marked by major, striking, and worldwide
changes in the types of fossils present.
9.) Period (101) - Units of geologic time characterized
by the types of life existing worldwide at the time,
Eras are divided into these.
10.) Epoch (101) - When periods are divided into smaller
units of time.
11.) Precambrian (108) -The longest part of Earth’s
history which lasted from 4.5 billion years ago to about
544 million years ago. Not many fossils at all.
12.) Paleozoic (110) –
 “Era of ancient life”.
 An abundance of organisms with hard parts, such as
shells, marked the beginning of this era.
 Many marine fossils due to shallow seas covering a
large part of Earth.
 Vertebrates, amphibians, and reptiles evolved during
this era.
13.) Mesozoic (116) –
 “Era of Middle Life”
 Pangaea began to break apart.
 Reptiles and Dinosaurs evolved.
 Birds, Mammals, Gymnosperms/ Non-Flowering Plants
(ex. Pine trees), and Angiosperms/ Flowering Plants.
14.) Cenozoic (120) “Era of Recent Life”
 Climate became cooler and “ice ages” occurred.
 Alps, Andes and Himalayan Mountains were created.
 Large Mammals- Elephants, horses, camels, deer,
humans, kangaroos, koala’s (marsupials).
15.) Present day Earth:
Cenozoic Quaternary Holocene
Era
Period
Epoch
END OF MESOZOIC- Meteorite collided with Earth,
causing a huge dust cloud to rise into the
atmosphere, blocking out the Sun.
END OF PALEOZOIC- meteorite and/or changes in
climate and lowering of sea-level due to the formation
of Pangaea. More land, less seas meaning less marine
life.