A useful index fossil must be
distinctive or easily recognizable, abundant, and have a wide geographic distribution and a short range through time
. Index fossils are the basis for defining boundaries in the geologic time scale
Which fossil could be a good index fossil?
Trilobites
are good index fossils. Why are trilobite fossils useful as index fossils?
What makes a good index fossil quizlet?
What makes a good index fossil and why is it different from other fossils?
It is distinctive, widespread, abundant and limited in geologic time. They were only alive for a short amount of time.
Why would humans make a good index fossil?
Some fossils are more useful than others in establishing the age of rocks. These are called index fossils. The best index fossils are
easy to recognize
, and are found over a large geo- graphic area, but they existed for a brief period of time.
Which three characteristics make a fossil species useful as an index fossil?
Characteristics of an Index Fossil
A good index fossil is one with four characteristics:
it is distinctive, widespread, abundant, and limited in geologic time
. Because most fossil-bearing rocks formed in the ocean, the major index fossils are marine organisms.
What is a good example of an index fossil?
There are some types of index fossils which include
Ammonites, Brachiopods, Graptolites, Nanofossils and Trilobites
. Ammonites: The fossil of ancient marine animals is said to be known as an ammonite index fossil. During the Mesozoic era, they were common (245 to 65 million years ago ).
Which species would make the best index fossil?
Trilobites
serve as good index fossils, letting geologists date the age of the rocks that they are in.
How do you find a good index fossil?
To find the index fossil you must
eliminate any fossils that don't show up in each rock outcrop
and those that show up in more than one layer per outcrop. We can eliminate “fossil 1” because it shows up in multiple layers in the same outcrop.
Which index fossil is youngest?
- Early Pleistocene 0.5 million.
- Tertiary Period.
- Eocene.
- Cretaceous Period 145 to 66 million.
- Jurassic Period.
- Triassic Period.
- Permian Period.
- Pennsylvanian Period.
Are trace fossils unique?
Ichnofossils, also known as trace fossils, are geological records of the activities and behaviors of past life. … These fossils are different from
body fossils that preserve the actual remains of a body such as shells or bones
.
What 5 pieces of information can the fossil record tell you?
Examples include
bones, teeth, shells, leaf impressions, nests, and footprints
. This evidence reveals what our planet was like long ago. Fossils also show how animals changed over time and how they are related to one another.
Why do we use index fossils instead of all fossils when trying to determine rock age?
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful
because they tell the relative ages of the rock layers in which they occur
.
Do scallops make for good index fossils?
These are the fossils that we want to use for relative dating. … Some of the scientists' favorite index fossils are trilobites, ammonites and
scallop shells
.
What are index fossils used for?
Keyed to the relative time scale are examples of index fossils, the forms of life which existed during limited periods of geologic time and thus are used as
guides to the age of the rocks in which they are preserved
.
Why would a shark not be a good index fossil?
A shark would not be a good index fossil
because the species has survived for too long
.
What are the two best environments to look for fossils?
It is often found in deserts, beaches, and other sandy environments. Shale is formed from particles of mud. Good places to find fossils are
outcrops
. An outcrop is a place where old rock is exposed by wind and water erosion and by other people's digging.
