Animal including salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of animals, plants, fungi and rocks. Animals are however not particularly heat tolerant; very few of them can survive at constant temperatures above . Only very few species of animals (mostly nematodes) inhabit the most extreme cold deserts of continental Antarctica. The blue whale ("Balaenoptera musculus") is the largest animal that has ever lived, weighing up to 190 metric tonnes and measuring up to long. The largest extant terrestrial animal is the African bush elephant ("Loxodonta africana"), weighing up to 12.25 tonnes and
Largest prehistoric animals is "Ptychodus", which was about long. The largest-known placoderm was the long "Dunkleosteus". It is estimated to have weighed around . Its relative, "Titanichthys", may have rivaled it in size. The largest-known is "Aegirocassis" at least long. The largest-known in this group was "Jaekelopterus rhenaniae" at in length. A close contender was "Pterygotus" at in length. There are two contenders for largest-known ever arachnid: "Pulmonoscorpius kirktonensis" and "Brontoscorpio anglicus". Pulmonoscorpius was Brontoscorpio was . The biggest difference is that "Brontoscorpio" was aquatic, and "Pulmonoscorpius" was terrestrial. "Brontoscorpio" is not to be confused with various Eurypterids: it was a true scorpion