Whales are the largest mammal on earth of all time. It is heavier than Elephants, Woolly mammoths and even Dinosaurs. But they weren’t always the titans of the sea.
If you look at in history around 50 million years earlier. You will not find any whales there. When you go to the seashore, you find Pakicetus, the very first species Whale.
Then what happened, how whales became the largest animal on earth ever?
The answer to this question is in the book “Spying on Whales” written by Nick Pyenson. Somewhere around 50 to 40 million years ago, they (whales) traded in their four legs for flippers. In fact, some whales today still have leftover bones of hind legs. Once the whales submerged in the ocean 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 was not a usual one. 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 was not until 300 million years ago, that an ice age tipped the scales in the whales’ favour. Ocean temperatures and currents shifted sparking concentrated swarms of plants down and plankton seeking krill. It was an all you can eat buffet for the baleen whales, as a result, they grew larger and larger.
The farther they could travel in search of food to grow even more. 3 million years later they were the longest migrant mammal on earth travelling over 5000 miles a year. As a result, modern whales are the largest they ever been in history.
You surprised to know that if you take the biggest bones of the blue whale, it weighs more than a Boeing 757, like a belly button the size of a plate. And it’s a network of blood vessels if you let them out in a line to distance from Pluto to the sun and back over two and half times. In fact, the largest blue whales are so huge, that the scientists think they may have hit a physical limit. Scientists estimate once a Whale is 110 feet long, it can’t close its mouth fast enough before prey escapes. So it’s possible we are living among the largest animal that will ever exist. Lucky for us they mostly eat krill.
The post-credit goes to Nick Pyenson and his book “Spying on Whales”.