The giant beaver is one of the largest rodents ever known. It could grow to be 2.5 metres long and weigh 218 kg. It was probably a distant cousin of our modern beaver. The giant beaver became extinct about 10,000 years ago. Some fossils have been found that are over 70,000 years old. They look like our present day beavers except for their size, their ridged teeth and perhaps their roundish muskrat-like tails. Their cutting teeth could be up to 15 cm. long. Judging from their teeth, they were herbivores (plant eaters) like the modern beaver. They lived in lodges. One was found that was 1.2 metres high and 2.4 metres in diameter. They seem to have preferred lakes and ponds bordered by swamps as their home.