Ichthyosaurs Were Aquatic Dinosaurs

Multiple Choice

Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are

A) homologous.
B) examples of convergent evolution.
C) adaptations to a common environment.
D) A and C only
E) B and C only