@sciants_media: When Is a Whale Not a Whale? Orca? Dolphin? Porpoise? Whale? What gives? Watch for an explanation! #marinebiology #dolphins #whales #taxonomy Sources: McGowen MR et al. Cetacean phylogeny and classification (Molecular Phylogenetics and Evolution, 2009). Gatesy J et al. Evolutionary relationships of cetaceans (Systematic Biology, 2013). Geisler JH & Theodor JM. Cetacean evolutionary history (Annual Review of Ecology, Evolution, and Systematics, 2009).