Question

select all the correct answers.

in the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence?

• mammals lived before the precambrian era.
• dinosaurs and mammals existed in the precambrian era.
• dinosaurs evolved after precambrian organisms.
• precambrian organisms evolved after dinosaurs.
• precambrian organisms were the first life-forms to become fossilized, according to this...

Explanation:

Analyze the rock layers

Using the Fossil Record knowledge point
According to the law of superposition, in an undisturbed sequence of rocks, the oldest layer is at the bottom and the youngest is at the top.

• Layer C (bottom): Precambrian fossils (oldest)
• Layer B (middle): Dinosaur fossils
• Layer A (top): Mammal fossils (youngest)

Evaluate statement 1 and 2

• "Mammals lived before the Precambrian era": Incorrect. Layer A (mammals) is above Layer C (Precambrian), meaning mammals lived much later.
• "Dinosaurs and mammals existed in the Precambrian era": Incorrect. Dinosaurs (Layer B) and mammals (Layer A) are in distinct, younger layers above the Precambrian layer (Layer C).

Evaluate statement 3

• "Dinosaurs evolved after Precambrian organisms": Correct. Layer B (dinosaurs) lies above Layer C (Precambrian), showing that dinosaurs appeared later in geological time.

Evaluate statement 4 and 5

• "Precambrian organisms evolved after dinosaurs": Incorrect. Layer C is below Layer B, meaning Precambrian organisms existed before dinosaurs.
• "Precambrian organisms were the first life-forms to become fossilized, according to this evidence": Correct. Layer C is the deepest (oldest) layer containing fossils in this sequence, showing they were fossilized first among the groups shown.

Answer:

• Mammals lived before the Precambrian era.
• Dinosaurs and mammals existed in the Precambrian era.
• Dinosaurs evolved after Precambrian organisms. (Correct answer)
• Precambrian organisms evolved after dinosaurs.
• Precambrian organisms were the first life-forms to become fossilized, according to this evidence. (Correct answer)