Input (grade 13): Biologist Stephen Jay Gould said the ichthyosaur was his favorite example of convergent evolution, where similarities of structure are analogous not homologous, for this group:
Output (grade 12): Biologist Stephen Jay Gould said the ichthyosaur was his favorite example of convergent evolution. Its similarities to fish are not homologous, caused by common descent, but analogous, caused by selection in the same environment: