Index fossils are fossilized remains of organisms that serve as convenient reference points to geologists because they were very widely distributed during a very short period. This means that, if a geologist is trying to figure out how old a certain segment of rock is, the presence of an index fossil will give him a very good idea to a pretty high level of certainty.
Most index fossils are aquatic, especially mollusks. This is because (a) mollusks had shells, which are easily preserved, and (b) marine organisms generally fossilize easily because they often live on sand and so turn into sedimentary rock, which forms without volcanic activity (like igneous) or intense pressure (like metamorphic).
One good example of an index fossil is Paradoxides, a species of trilobite that was distributed in seas all over the world, but only for a very small amount of time during the Cambrian Period, about 540 million years ago.
Index fossils are the remains of organisms that lived during a very specific and well-defined time span, and are able to be recognized from various, distant locations; hence, they are usually marine invertebrates like trilobites or ammonites. They are able to provide a means of dating fossils found with them or in layers above and below them.
It gives information to scientists about the past. It also provides a reference of time throught rock layers. It can identify and define geological periods of time.
They use Index Fossils to study extinct plants or animals from certian time periods
It gives information to scientists about the past. It also provides a reference of time throught rock layers. It can identify and define geological periods of time.
Index fossils are very important to geologists because they identify geological. The fossil snail is a particularly difficult animal to study.
they tell the absoute age of rcoks which they occur
The absolute age of the index fossil was determine by radioactive dating or another absolute method
it must have lived through a long span of time
It gives information to scientists about the past. It also provides a reference of time throught rock layers. It can identify and define geological periods of time.
Index Fossil
Index fossils are very important to geologists because they identify geological. The fossil snail is a particularly difficult animal to study.
An index fossil must be of a rapidly evolving organism that only existed for a specific period of time, is easily recognizable, is abundantly preserved, and was widespread geographically. Most index fossils are therefore of marine organisms.
they tell the absoute age of rcoks which they occur
To be useful as an index fossil fuel, spices must have existed for about 1000 years.
C). a narrow time range and a wide geographic range
The absolute age of the index fossil was determine by radioactive dating or another absolute method
Index fossils are very important to geologists because they identify geological time periods. Index fossils are found within a specific layer of rock- So when one finds the age of the rock layer, that is also the age of the index fossil.
It gives information to scientists about the past. It also provides a reference of time throught rock layers. It can identify and define geological periods of time.
it must have lived through a long span of time
False.