Refer to the figure. The figure depicts a layer of iridium at the Cretaceous-Tertiary (K/T) boundary between strata from two different periods in Earth's history.The only _______ fossils found above the K/T boundary are those of birds.

Question

Refer to the figure.  The figure depicts a layer of iridium at the Cretaceous-Tertiary (K/T) boundary between strata from two different periods in Earth's history.The only _______ fossils found above the K/T boundary are those of birds.

Quizplus · Accepted Answer

The layer of iridium at the K/T boundary is evidence for a catastrophic event, likely an asteroid impact, which is thought to have caused the mass extinction of non-avian dinosaurs. Therefore, the only fossils found above the K/T boundary are those of birds, which are the only surviving group of dinosaurs. The other choices (A) flying animal, (B) amniote, (D) warm-blooded animal, and (E) Cretaceous do not accurately reflect the evidence presented in the figure.

Refer to the Figure