How Whales became the largest mammal on earth.
Whales are the biggest animals of all time, heavier than Elephants, Woolly mammoths and even Dinosaurs. But they weren’t always the titans of the sea. Let’s rewind the clock around 50 million years. No, you won’t find any whales here. you have to go ashore, meet Pakicetus, the very first Whale.
How they became the largest animal ever.
Life on earth spend millions of years clawing its way out of the oceans. But Whales took all that effort and threw it out the window. From 50 to 40 million years ago, they traded in their four legs for flippers. In fact, some Whales today still have leftover bones of hind legs. Once submerged their weight under gravity no longer matters. So they could theoretically grow to enormous proportions and they did. Today a blue whale is 10,000 times more massive than the original Pakicetus was. But this transformation wasn’t as usual as you might think. In fact, over the next 37 million years or so, whales grew increasingly diverse, but their size remains small. For example, one of the first ones with baleen instead of teeth was only 18 feet long, making them easy prey for predators like a giant shark.
It wasn’t until around 300 million years ago, that an ice age tipped the scales in the whales’ favour. Ocean temperatures and current shifted sparking concentrated swarms of plants down and plankton seeking krill. It was an all you can eat buffet for the baleen whales, who grew larger as a result and the last they became. The farther they could travel in search of food to grow even more. 3 million years later, humpback, for example, have one of the longest migration of any mammal on earth travelling over 5000 miles a year. As a result, modern whales are the largest they ever been in history.
Take the biggest of the bones, the blue whale it weighs more than a Boeing 757,
The post credit goes to Nick Pyenson and his book “Spying on Whales”.
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