2 Points
What is an index fossil?
O
A. A fossil that contains rocks and minerals
O
B. A fossil found in rocks from one time period
O
C. A fossil that has vestigial structures
O
D. A fossil that formed 300 million years ago

B, A fossil found in rocks from one time period

Explanation:

Fossils are used to determine the ages of rock layers. Index fossils are the most useful for this. Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in. Hope that this helps you :)

this transfer is call conjunction

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.