Today's #megafauna is Basilosaurus! This Eocene #whale was about 60 feet long and sported tiny hind limbs. It is possible that the hind limbs were used to hold onto partners during mating, though they were disconnected from the rest of the whale skeleton and could not have supported weight on land. Basilosaurus's elongated shape and small tail flukes suggest that it swam by moving most of its body up and down--not just its tail.

Although this may sound like a silly mode of transportation, #Basilosaurus was the apex #preadtor of its time. With strong jaw muscles, large incisors, and serrated molars at the back of its mouth, this whale proved a formidable foe for #fish, #sharks, and even other #MarineMammals.

At Whale Valley--a rich source of marine fossils that was likely an Eocene nesting ground--#fossil evidence paints a picture of Basilosaurus's hunting habits. Nesting fossils show the contents of its stomach, and specimens of another whale species, dorodon, show bite marks consistent with Basilosaurus's teeth. Most dorodon fossils nested in Basilosaurus skeletons are juveniles--suggesting that Basilosaaurus lurked near these nesting grounds, targeting young dorodons just as modern #orcas target the calves of other whales.