|Basilosaurus on display in the Life in the Ancient Seas exhibit, 1989. Photo by Chip Clark, Smithsonian Institution|
04 February 2017
The earliest whales walked the shorelines of swamps and oceans. The earliest large fully aquatic whales that we know of and would recognize as whales were still rather alien appearing in terms of what we think of as whales; however, their largest representatives could be mistaken for nothing else due to their size and mammalian characteristics. The king of these early whales, by name the "king lizard", was Basilosaurus. Consisting of two recognized species, B. cetoides and B. isis, Basilosaurus was a predatory whale measuring up to 18 m (59 ft) long and possessing a skull and feeding apparatus capable of an estimated 20,000 pounds per square inch of force during an extreme bite. Flippers extending 35 cm (14 in) stabilized the whale as it propelled itself through the water with a hypothesized undersized, by modern standards, fluke capable vertical movements possessing either a dorsal fin or ridge along the midline of the tail. This structure is hypothesized currently and its exact size and morphology are unknown presently, though support for both morphologies have been published in the past.