Geological Time Scale and Fossils
Flashcard maker : Ruth Blanco
Name for the time in earths early history that accounts for ninety percent of earth’s time, but only cellular organisms lived.
the part of geologic time 570-245 million years ago ; invertebrates, fishes, amphibians, reptiles, ferns, and cone-bearing trees were dominant
middle life (245-144 million years ago); rise of mammals and dinosaurs; the rise of birds; extinction of dinosaurs, rise of flowering plants
Era of recent that began about 66 MYA, and continues today. Includes the first appearance and homo sapiens about 400,000 years ago
The unit of time that comes after era.
The unit of time that comes after period.
Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock
Law of Superposition
The geologic principle that states that in horizontal layers of sedimentary rock, each layer is older than the layer above it and younger than the layer below it.
a fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is found
a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
a space in a rock that has the shape of the remains of a living thing that once occupied that space.
a model in the shape of a living thing or its remains, it forms when minerals or rock particles fill the space
Forms when entire organisms or parts, like leaves, stems, flowers, fish, are pressed between layers of soft mud or clay
forms when entire organisms or parts of organisms are prevented from decaying by being trapped in rock, ice, tar, or amber.
a fossil in which minerals replace all or part of an organism
layers of rock
Chronological collection of life’s remains in sedimentary rock layers
The disappearance of all members of a species from Earth