Question

Which phrases describe organisms that formed index fossils? Check all that apply.

Answer 1

Answer:

• are extinct
• had hard parts
• were generally large
• were alive only for a short time

Explanation:

• The index fossils are also called s the guide fossils and are used to identify the geological periods. The index fossils are known to have a short-range with the geographical distribution and have a rapid evolutionary trend.

• This is found during the Mesozoic era of the 245 to 65 million years. These are easily distinguished and identify the type of species and are recognized and were abundantly found during the cambrian and ordovician periods.

Answer 2

are extinct, had hard parts,were generally large and were alive only for a short time.

Explanation:

Index fossils typically are extinct organisms that have hard parts that have been preserved till date. They are generally large in population but their body size might vary and only alive for a short period in time.

• Index fossils are also known as guide fossils or indicator fossils.
• They help to define geologic periods more appropriately and fittingly.
• Like every other remains of organisms preserved in rocks, they must have preservable hard parts.
• Their population must be abundant so as to increase their chances of being preserved.
• They must also be extinct. Extinction is the mass loss of a specie. If they are not extinct, they might not be good indicators of time. Extinction confines the life history of organism into a proper time frame.

Learn more:

Fossils brainly.com/question/12790206

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