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 mammals and not fish. The largest animal that ever lived is the blue whale. The blue whale can weigh 200 tons and measures almost 100 feet. But some other extinct animals were longer, if not heavier than blue whales, most being dinosaurs. Among those of the largest extinct animals are the great sauropod dinosaurs.