Question

this diagram shows fossils in an undisturbed sedimentary rock sequence. shallower deeper which of the following fossils is oldest? select the most likely answer. turtle shell crab claw fish

Explanation:

Step1: Recall the principle of superposition

In undisturbed sedimentary rock layers, the oldest layers are at the bottom (deeper) and the youngest at the top (shallower).

Step2: Identify the depth of each fossil

• The turtle shell fossil is in the deepest layer (bottom layer).
• The crab claw fossil is in a layer above the turtle shell's layer.
• The fish fossil is in a layer above the turtle shell's layer but below the crab claw's? Wait, no, looking at the diagram: the bottom layer (deepest) has the turtle shell, then the fish layer, then the crab claw layer, then the top (shallowest) with the urchin - like fossil. Wait, no, the layers from deeper to shallower: first (deepest) is the brown layer with turtle shell, then white layer with fish, then beige layer with crab claw, then black layer with urchin. So the deepest layer (oldest) has the turtle shell.

Step3: Determine the oldest fossil

Since the turtle shell is in the deepest (oldest) layer among the three options, it is the oldest.

Answer:

A. turtle shell (assuming the first option is turtle shell, as per the labels: first image is turtle shell, second crab claw, third fish. So the oldest is the turtle shell fossil, so the option with turtle shell, e.g., if options are labeled as first: turtle shell, second: crab claw, third: fish, then the answer is the turtle shell option. So in the given options, the turtle shell is the oldest.