Simplify the following text for a Grade 10 native English-speaking person.
Original: By the Carboniferous period many of the shapes we see in living gastropods can be matched in the fossil record , but despite these similarities in appearance the majority of these older forms are not directly related to living forms .
Simplified: By the Carboniferous period many of the shapes seen in living gastropods can be matched in the fossil record . Despite these similarities in appearance , the majority of these older forms are not directly related to living forms .