10 Days, 10 Amazing Facts about Dolphins!
Day 6: Did You Know? Orcas or killer whales are actually dolphins!
They are the largest of the dolphin family (Family Delphinidae ~ 32 species, including what we normally consider dolphins, pygmy killer whales, Feresa attenuata, and false killer whales, Pseudorca crassiddens). (marinebio)
See the orcas in the wild at explore.org