A perucetus colossus is bigger than a blue whale and was around 66 feet long and weighs up to 350 metric tons.
A blue whale is very big and weighs between 290,000 lbs to as much as 330,000 lbs and can reach up to 110 feet in length.
Female blue whales are usually larger than male blue whales and blue whales have a lifespan of around 80 years to 90 years with a heart size of 5 feet long.
The amount of blue whales that are left in the world is around 25,000 blue whales.
Blue whales are still facing a multitude of threats from human interference so the population of blue whales in the world are declining.
Blue whales do still exist and there are 5 recognized subspecies of blue whales.
Today the number of blue whales is only a small fraction of what it was before modern commercial whaling reduced the number of whales significantly during the early 1900s.
However populations of blue whales are increasing globally still.
Before whaling began, there may have been as many as 250,000 blue whales, but today, the blue whale is one of the world's rarest species of whales, with a population of just 10,000-25,000.
The blue whales face a multitude of threats from human interference.
Blue whales are a marine mammal and a baleen whale.
Blue whales reach a maximum confirmed length of 29.9 meters and weigh up to 199 tonnes, and they are the largest animal known ever to have existed.
A blue whale's long and slender body can be of various shades of greyish-blue dorsally and somewhat lighter underneath.
The blue whale is the largest known animal to have ever lived.
An adult blue whale can grow to a massive 30m long and weigh more than 180,000kg which is about the same as 40 elephants, 30 Tyrannosaurus Rex or 2,670 average-sized men.
Primary threats blue whales face include commercial whaling, noise pollution, ship strikes, and climate change, which affects their food sources and habitats.
The blue whale has a dive time that varies from around 10 to 30 minutes, which is not enough to earn the species the record for the longest dive.
Blue whales were targeted for the rich rewards their huge bodies held.
The whaling ships used in the twentieth century were fast enough to catch even the quickest whales, and had mechanical weapons on board - including exploding harpoons.