Fossils

Which part of an organism is preserved in cast and mold fossils?

• skin

• bone

• muscle

• soft tissue

Which correctly lists three materials that preserve soft tissues in fossils?

• amber, minerals, and sediment

• minerals, permafrost, and amber

• permafrost, amber, and tar

• sediment, minerals, and amber

Why is still water an ideal environment for the formation of mold and cast fossils?

• Sediment builds up over organisms.

• Sediment turns organisms into rock.

• Hard tissue decays under sediment.

• Soft tissue is preserved under sediment.

How do organisms form carbon films?

• Organisms turn into rock.

• Residue is left on rocks when organisms decay.

• Hollow forms are left in sediment by decaying organisms.

• Organisms leave evidence of their activities, such as footprints.

What happens to soft parts of organisms when cast fossils form?

• They decay.

• They petrify.

• They form carbon films.

• They become part of the fossil.

How are casts formed by decaying organisms?

• Organisms turn into rock over time.

• Organisms leave carbon residue on a rock.

• Organisms leave impressions in sediment that hardens into rock.

• Impressions left by organisms are filled in with sediment that hardens into rock.

Tags

NGSS.MS-LS4-1

Which type of fossils form from hardening sediment?

• casts

• tar pit fossils

• carbon films

• amber fossils

Which feature do amber fossils have that mold fossils do not?

• preserved soft tissue

• organisms turned into rock

• solid copies of the original organism

• impressions of hard tissue left by organisms

How does this fossil differ from fossils that have preserved remains?

Which feature does this fossil have that preserved remains do not have?

• It has carbon residue left by a decaying organism.

• It was formed by tree sap that turned into amber.

• It was preserved in frozen soil called permafrost.

• It includes the preserved soft tissue of an organism.

Tags

NGSS.MS-LS4-1

The image shows a fossil that is hard like rock but that resembles a tree.

Which statement explains how this type of fossil differs from a trace fossil?

• This fossil reveals the activities of an organism.

• This fossil was created in solidifying sediment.

• This fossil is an impression left by an organism.

• This fossil was an organism that has been turned into rock.

Tags

NGSS.MS-LS4-1