During a mass extinction event, a vast number of species die off during a relatively short geological time. This can be seen in fossil layers found in sedimentary rock.

Question

The following table shows data about the types of fossils found in certain sedimentary rock layers from the surface down to the lowest rock layer (Rock Layer E):

Rock Layer Fossils Found
Surface None
A A1, A2, B2, B3
B B1, B2, B3
C C1, C2, D2, E2, E3
D D1, D2, E2, E3
E E1, E2, E3
Examine the fossils found in each layer. Based on this fossil record data, between which two rock layers does there appear to have been a mass extinction event?

(1 point)
Responses

B and C
B and C

C and D

Answer 1

Based on the fossil record data provided, a mass extinction event appears to have occurred between Rock Layer B and Rock Layer C.

This is evident because Rock Layer B contains fossils B1, B2, and B3, while Rock Layer C contains a different set of fossils (C1, C2, D2, E2, E3). Since there is no overlap in the fossil types between these two layers, it suggests that a significant number of species went extinct during this transition, indicative of a mass extinction event.

Therefore, the correct response is: B and C.