How do hypercarniverous whales differ from modern whales?

Answer 1

There were several apex predator whales during the Cenozoic era.

The first in fossil register from the early Eocene period was Basilosaurus cetoides, a rather slim but very large (up to 20 metres long) odontoceti whale that preyed on sharks and bony fish.

But the indisputably top predator of all whale species ever was Livyatan melvillei, the only possible contender of C. megalodon on the Miocene oceans.

Very few fossil remains have been found after the first discovery, in 2008, of Livyatan melvillei, and no complete fossil skeleton has been found to this day.

However, the maximum total lenght of Livyatan melvillei must have been 17 metres, or possibly even larger.

The big difference of these prehistoric odontoceti whales from contemporaneous toothed whales, like the sperm whale (Physeter macrocephalus), lies in the fact that the early «hypercarnivorous» whales had teeth in upper AND lower jaws, unlike the sperm whale, which has teeth only in the lower jaw. The only possible exception could have been the Aulophyseterwhale from late Miocene, but this is still a matter of debate among paleontologists.

Livyatan melvillei had the largest teeth EVER from a carnivorous animal (including dinosaurs, pliosaurs and mosasaurs), more than 36 cm in total lenght. Larger fossil remains of this monster whale are expected to be discovered.

Just to make a comparison, the largest fossil teeth of C. megalodon is 19,4 cm, and it was found by professional fossil hunter Vito Bertucci, worldwide known as the «Megalodon Man». He died recently during a very dangerous dive in the Ogeechee River, near the Intercoastal Waterway in Bryan county, searching for even larger meg teeth. Vito Bertucci was aged 48.