lower1. 1  to cause to descend; let or put down: to lower a flag. 2  to make lower in height or level: to lower the water in a canal. 3  to reduce in amount, price, degree, force, etc. 4  to make less loud: Please lower your voice.
Biggest Whale-Basilosaurus (60 Tons). Basilosaurus (Nobu Tamura). Unlike the other mammals on this list, Basilosaurus can't lay claim to being the largest-ever of its breed--that honor belongs to the still-extant Blue Whale, which can grow to as much as 200 tons.
Blue whales are the largest animal ever to have lived - even larger than the dinosaurs. They are a sub-species of baleen whale, feeding mainly on krill, that can grow to up to 30 metres long, and weigh 100-150tonnes. Their mouths could hold up to 100 people, and their hearts are the size of a small car.