Geologists determine the geological history of an area by examining rock
layers in geologic columns. The diagram
shows three geologic columns from the
same region that have not been
overturned
A Place an arrow at each rock layer
boundary to represent a missing layer
of rock in each of the three columns
В.
Select the oldest rock layer
represented in the group of geologic
columns
• You may use the arrow more than once.
• There may be more than one correct
answer

Even though the ostrich is a flightless bird, ostriches still possess wings that stretch approximately two meters across when fully extended. scientists speculate that when dinosaurs became extinct, some of the birds that lived during that time became land dwellers since they were able to consume the food that the dinosaurs once ate. over time, these species grew larger and heavier. eventually, the ostrich species became too big to fly. the wings found on ostriches are known as a. analogous structures. b. homologous structures. c. vestigial structures. d. symmetrical structures.