[quote]About 6 million years ago, the seas off Peru were much warmer than today, by at least 4°C. The middle part of the Miocene period (23–5.3 million years ago) had been a warm time throughout the world, with sea temperatures soaring to 31°C in places. That was a time of great expansion of whales and other marine life as productivity soared in the oceans.

In the final million years of the period, two of the three marine gateways connecting the warmer tropical seas together had closed, blocked by tectonic uplifts. This caused a dramatic rerouting of oceanic currents, resulting in abrupt cooling of the oceans. Food resources were on the wane, so predators had to hunt harder for food.

Gigantic predators had an even harder time, as they needed much more food each day than smaller creatures.

[Baleen] whales belong to an extinct species called Piscobalaena. They were slow-moving animals that looked a lot like a scaled-down version of today’s southern right whales, with the oldest individuals reaching around 5 metres.

Megalodon—the female was larger than the male—could eat such a whale in 2-3 bites.

https://theconversation.com/friday-essay-giant-shark-megalodon-was-the-most-powe...