Largest organisms one of the largest and oldest clonal colonies on Earth. Among animals, the largest species are all marine mammals, specifically whales. The blue whale is believed to be the largest animal to have ever lived. The largest land animal classification is also dominated by mammals, with the African bush elephant being the most massive of these. The largest single-stem tree by wood volume and mass is the giant sequoia ("Sequoiadendron giganteum"), native to Sierra Nevada and California; it typically grows to a height of and in diameter. Multiple-stem trees such as banyan can be enormous. Thimmamma Marrimanu in India spreads
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