Paleontology Flashcards
Paleontology
Paleontology is the study of the history of life on Earth via fossil record.
fossil
remains of an organism or evidence of them preserved in rock. usually found in sedimentary rock.
Fossilization
Process of an organism’s body or other evidence of their life is preserved (typically in rock).
Stages of fossilization
Death
Burial
Preservation
Uplift/Erosion
Discovery/Recovery
Death
organism must die.
soft body parts are decomposed leaving only hard body parts, such as bones and shells.
Burial
Buried by sediments
The faster this step occurs, the more likely it will be that the remains will undergo fossilization
More detail is preserved if it is buried in smaller sediments (e.g., clay, silt,)
Preservation
silica, preserving their shape, Hollow cavity
Uplift/Erosion
Uplift: Rocks that were previously underground or underwater can be brought up to surface by the action of tectonic plates.
By lifting layers of sedimentary rocks, fossils can be exposed.
Erosion by wind and water can remove sedimentary rock, exposing rock layers and the fossils they contain.
Discovery/Recovery
Fossils can be found on the surface or evidence of a fossil can be seen via familiar shapes and patterns in rock indicating they may be there.
Original Remains
The organism’s original tissue makes up all or part of the fossil.
Examples of original remains are bodies of animals, plants and even humans frozen in glaciers.
Molds Fossils
Original organism are replaced with minerals from the groundwater.
The replaced remains dissolve and leave behind a mold, which later minerals may fill to create a cast of the original organism.
Trace Fossils
No actual part of the organism is left in a trace fossil.
Trace fossils can give information about the location and behaviour of organisms.
Examples include tracks, footprints, bite marks, burrows and feces.
Trail and Burrow Fossils
Created by ancient animals moving around on soft material known as trails fossils.
Burrowing animals created hollow underground structures that filled with sediment over time. These hollow structures are known as burrow fossils.
Evolution
Fossils provide a detailed, but incomplete, record of life on Earth over billions of years.
Comparisons of fossils from different periods of time provide direct evidence for the evolution of species.
Relative Dating
Determining which layers are younger and which ones are older based on their positions
stratigraphic sequence.
A series of rock layers found together
Index Fossils
well preserved organisms, that lived large areas during specific time periods
Paleoclimatology
the study of past climates.
- examing the physical characteristics of plants
-how they are distributed in various climates around the world today, plant fossils allow scientists to make inferences about climates in the past.
Radiometric Dating
technique used to determine the absolute age of many geological samples including organic materials, volcanic rock layers and meteorites.
Radioactive Decay
Radiometric dating relies on radioactive decay.
a process which an isotope of an element undergoes a nuclear reaction to form an isotope of a different element.
1.The initial element undergoing decay is known as the parent element.
2.The element produced in the decay is known as the daughter element.
Isotopes
version of an element with a different number of protons and neutrons than normal.
Radioactive Dating Using Carbon-14
taken into plants through photosynthesis and into animals through food chains. When an organism dies, stops incorporating new carbon-14 atoms into its body.
Scientists can estimate the age of an organism’s remains by measuring the amount of carbon-14 remaining in a sample of the remains.
Half-Life
The half-life of a radioisotope is the time it takes for half of the atoms to undergo radioactive decay.
