Paleontology Flashcards
What is paleontology?
Paleontology is the study of life’s history as revealed in the preserved remains of once-living organisms.
What is a fossil?
A fossil is the preserved remains of a once-living organism.
What is petrifaction?
Petrifaction is the conversion of organic material into rock.
What is resin?
Resin is a thick, slowly flowing liquid produced by plants that can harden into a solid.
What is the fossil record?
The fossil record is the sum total of all fossils discovered.
What does it mean to say that a species is extinct?
When a species is extinct, then there are no living representatives of that species that we know of.
What were placoderms?
Placoderms were fish that had bony plates covering their heads rather than the scales that cover the heads of modern fish. They are assumed to be extinct.
What are amphibians?
Amphibians are creatures that live both in and out of water.
Four General Features of the Fossil Record
- Fossils are usually found in sedimentary rock, which is usually laid down by water. This suggests that most fossils were laid down by water.
- The vast majority of fossils are hard-shelled creatures. Most of the rest are either water-dwelling creatures or insects. Very few fossils are of plants, reptiles, birds, and mammals.
- Some fossils are of extinct organisms. Some fossils are of organisms that are still alive.
- Fossils in one layer of rock can be very different from fossils in another.
What are index fossils?
Index fossils are fossils that are assumed to represent a certain period in earth’s past.
What is the geological column?
The geological column is a theoretical picture in which layers of rock from around the world are meshed into a single, unbroken record of earth’s past.
