 These whales and "Llanocetus" may form a clade of toothed baleen whales of the Southern Hemisphere, a sister clade to Aetiocetidae and more modern baleen-bearing baleen whales.The name "Mammalodon" is said to be derived from English "mammal" and Ancient Greek "odontos" tooth, meaning "mammal tooth," as its molar teeth are similar to those found in terrestrial carnivores.The Ancient Greek for "tooth" is however odous (ὀδούς).